(Slip Opinion)              OCTOBER TERM, 2013                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

                       BOND v. UNITED STATES

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                  THE THIRD CIRCUIT

     No. 12–158.      Argued November 5, 2013—Decided June 2, 2014
To implement the international Convention on the Prohibition of the
  Development, Production, Stockpiling, and Use of Chemical Weapons
  and on Their Destruction, Congress enacted the Chemical Weapons
  Convention Implementation Act of 1998. The statute forbids, among
  other things, any person knowingly to “possess[ ] or use . . . any
  chemical weapon,” 18 U. S. C. §229(a)(1). A “chemical weapon” is “[a]
  toxic chemical and its precursors, except where intended for a pur-
  pose not prohibited under this chapter.” §229F(1)(A). A “toxic chem-
  ical” is “any chemical which through its chemical action on life pro-
  cesses can cause death, temporary incapacitation or permanent harm
  to humans or animals. The term includes all such chemicals, regard-
  less of their origin or of their method of production, and regardless of
  whether they are produced in facilities, in munitions or elsewhere.”
  §229F(8)(A). “[P]urposes not prohibited by this chapter” is defined as
  “[a]ny peaceful purpose related to an industrial, agricultural, re-
  search, medical, or pharmaceutical activity or other activity,” and
  other specific purposes. §229F(7).
     Petitioner Bond sought revenge against Myrlinda Haynes—with
  whom her husband had carried on an affair—by spreading two toxic
  chemicals on Haynes’s car, mailbox, and door knob in hopes that
  Haynes would develop an uncomfortable rash. On one occasion
  Haynes suffered a minor chemical burn that she treated by rinsing
  with water, but Bond’s attempted assaults were otherwise entirely
  unsuccessful. Federal prosecutors charged Bond with violating,
  among other things, section 229(a). Bond moved to dismiss the chem-
  ical weapons charges on the ground that the Act violates the Tenth
  Amendment. When the District Court denied her motion, she plead-
  ed guilty but reserved the right to appeal. The Third Circuit initially
2                      BOND v. UNITED STATES

                                 Syllabus

    held that Bond lacked standing to raise her Tenth Amendment chal-
    lenge, but this Court reversed. On remand, the Third Circuit rejected
    her Tenth Amendment argument and her additional argument that
    section 229 does not reach her conduct.
Held: Section 229 does not reach Bond’s simple assault. Pp. 8–21.
    (a) The parties debate whether section 229 is a necessary and
 proper means of executing the Federal Government’s power to make
 treaties, but “normally [this] Court will not decide a constitutional
 question if there is some other ground upon which to dispose of the
 case.” Escambia County v. McMillan, 466 U. S. 48, 51 (per curiam).
 Thus, this Court starts with Bond’s argument that section 229 does
 not cover her conduct. Pp. 8–9.
    (b) This Court has no need to interpret the scope of the interna-
 tional Chemical Weapons Convention in this case. The treaty speci-
 fies that a signatory nation should implement its obligations “in ac-
 cordance with its constitutional processes.” Art. VII(1), 1974 U. N. T.
 S. 331. Bond was prosecuted under a federal statute, which, unlike
 the treaty, must be read consistent with the principles of federalism
 inherent in our constitutional structure. Pp. 10–21.
      (1) A fair reading of section 229 must recognize the duty of “fed-
 eral courts to be certain of Congress’s intent before finding that fed-
 eral law overrides” the “usual constitutional balance of federal and
 state powers,” Gregory v. Ashcroft, 501 U. S. 452, 460. This principle
 applies to federal laws that punish local criminal activity, which has
 traditionally been the responsibility of the States. This Court’s prec-
 edents have referred to basic principles of federalism in the Constitu-
 tion to resolve ambiguity in federal statutes. See, e.g., United States
 v. Bass, 404 U. S. 336; Jones v. United States, 529 U. S. 848. Here,
 the ambiguity in the statute derives from the improbably broad reach
 of the key statutory definition, given the term—“chemical weapon”—
 that is being defined, the deeply serious consequences of adopting
 such a boundless reading, and the lack of any apparent need to do so
 in light of the context from which the statute arose—a treaty about
 chemical warfare and terrorism, not about local assaults. Thus, the
 Court can reasonably insist on a clear indication that Congress in-
 tended to reach purely local crimes before interpreting section 229’s
 expansive language in a way that intrudes on the States’ police pow-
 er. Pp. 10–14.
      (2) No such clear indication is found in section 229. An ordinary
 speaker would not describe Bond’s feud-driven act of spreading irri-
 tating chemicals as involving a “chemical weapon.” And the chemi-
 cals at issue here bear little resemblance to those whose prohibition
 was the object of an international Convention. Where the breadth of
 a statutory definition creates ambiguity, it is appropriate to look to
                      Cite as: 572 U. S. ____ (2014)                       3

                                 Syllabus

  the ordinary meaning of the term being defined (here, “chemical
  weapon”) in settling on a fair reading of the statute. See Johnson v.
  United States, 559 U. S. 133.
    The Government’s reading of section 229 would transform a statute
  concerned with acts of war, assassination, and terrorism into a mas-
  sive federal anti-poisoning regime that reaches the simplest of as-
  saults. In light of the principle that Congress does not normally in-
  trude upon the States’ police power, this Court is reluctant to
  conclude that Congress meant to punish Bond’s crime with a federal
  prosecution for a chemical weapons attack. In fact, only a handful of
  prosecutions have been brought under section 229, and most of those
  involved crimes not traditionally within the States’ purview, e.g., ter-
  rorist plots.
    Pennsylvania’s laws are sufficient to prosecute assaults like
  Bond’s, and there is no indication in section 229 that Congress in-
  tended to abandon its traditional “reluctan[ce] to define as a federal
  crime conduct readily denounced as criminal by the States,” Bass,
  supra, at 349. That principle goes to the very structure of the Consti-
  tution, and “protects the liberty of the individual from arbitrary pow-
  er.” Bond v. United States, 564 U. S. ___, ___. The global need to
  prevent chemical warfare does not require the Federal Government
  to reach into the kitchen cupboard. Pp. 15–21.
681 F. 3d 149, reversed and remanded.

   ROBERTS, C. J., delivered the opinion of the Court, in which KENNEDY,
GINSBURG, BREYER, SOTOMAYOR, and KAGAN, JJ., joined. SCALIA, J.,
filed an opinion concurring in the judgment, in which THOMAS, J.,
joined, and in which ALITO, J., joined as to Part I. THOMAS, J., filed an
opinion concurring in the judgment, in which SCALIA, J., joined, and in
which ALITO, J., joined as to Parts I, II, and III. ALITO, J., filed an opin-
ion concurring in the judgment.
                        Cite as: 572 U. S. ____ (2014)                              1

                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     preliminary print of the United States Reports. Readers are requested to
     notify the Reporter of Decisions, Supreme Court of the United States, Wash-
     ington, D. C. 20543, of any typographical or other formal errors, in order
     that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 12–158
                                   _________________


    CAROL ANNE BOND, PETITIONER v. UNITED

                  STATES 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE THIRD CIRCUIT

                                 [June 2, 2014]


  CHIEF JUSTICE ROBERTS delivered the opinion of the
Court.
  The horrors of chemical warfare were vividly captured
by John Singer Sargent in his 1919 painting Gassed. The
nearly life-sized work depicts two lines of soldiers, blinded
by mustard gas, clinging single file to orderlies guiding
them to an improvised aid station. There they would
receive little treatment and no relief; many suffered for
weeks only to have the gas claim their lives. The soldiers
were shown staggering through piles of comrades too
seriously burned to even join the procession.
  The painting reflects the devastation that Sargent
witnessed in the aftermath of the Second Battle of Arras
during World War I. That battle and others like it led to
an overwhelming consensus in the international commu-
nity that toxic chemicals should never again be used as
weapons against human beings. Today that objective is
reflected in the international Convention on Chemical
Weapons, which has been ratified or acceded to by 190
countries. The United States, pursuant to the Federal
Government’s constitutionally enumerated power to make
2                 BOND v. UNITED STATES

                     Opinion of the Court

treaties, ratified the treaty in 1997. To fulfill the United
States’ obligations under the Convention, Congress en-
acted the Chemical Weapons Convention Implementation
Act of 1998. The Act makes it a federal crime for a person
to use or possess any chemical weapon, and it punishes
violators with severe penalties. It is a statute that, like
the Convention it implements, deals with crimes of deadly
seriousness.
  The question presented by this case is whether the
Implementation Act also reaches a purely local crime: an
amateur attempt by a jilted wife to injure her husband’s
lover, which ended up causing only a minor thumb burn
readily treated by rinsing with water. Because our consti-
tutional structure leaves local criminal activity primarily
to the States, we have generally declined to read federal
law as intruding on that responsibility, unless Congress
has clearly indicated that the law should have such reach.
The Chemical Weapons Convention Implementation Act
contains no such clear indication, and we accordingly
conclude that it does not cover the unremarkable local
offense at issue here.
                              I

                             A

  In 1997, the President of the United States, upon the
advice and consent of the Senate, ratified the Convention
on the Prohibition of the Development, Production, Stock-
piling, and Use of Chemical Weapons and on Their De-
struction. S. Treaty Doc. No. 103–21, 1974 U. N. T. S. 317.
The nations that ratified the Convention (State Parties)
had bold aspirations for it: “general and complete dis-
armament under strict and effective international control,
including the prohibition and elimination of all types of
weapons of mass destruction.” Convention Preamble, ibid.
This purpose traces its origin to World War I, when “[o]ver
a million casualties, up to 100,000 of them fatal, are esti-
                 Cite as: 572 U. S. ____ (2014)           3

                     Opinion of the Court

mated to have been caused by chemicals . . . , a large part
following the introduction of mustard gas in 1917.” Ken-
yon, Why We Need a Chemical Weapons Convention and
an OPCW, in The Creation of the Organisation for the
Prohibition of Chemical Weapons 1, 4 (I. Kenyon & D.
Feakes eds. 2007) (Kenyon & Feakes). The atrocities of
that war led the community of nations to adopt the 1925
Geneva Protocol, which prohibited the use of chemicals as
a method of warfare. Id., at 5.
    Up to the 1990s, however, chemical weapons remained
in use both in and out of wartime, with devastating conse-
quences. Iraq’s use of nerve agents and mustard gas
during its war with Iran in the 1980s contributed to inter-
national support for a renewed, more effective chemical
weapons ban. Id., at 6, 10–11. In 1994 and 1995, long-
held fears of the use of chemical weapons by terrorists
were realized when Japanese extremists carried out two
attacks using sarin gas. Id., at 6. The Convention was
conceived as an effort to update the Geneva Protocol’s
protections and to expand the prohibition on chemical
weapons beyond state actors in wartime. Convention
Preamble, 1974 U. N. T. S. 318 (the State Parties are
“[d]etermined for the sake of all mankind, to exclude
completely the possibility of the use of chemical weapons,
. . . thereby complementing the obligations assumed under
the Geneva Protocol of 1925”). The Convention aimed to
achieve that objective by prohibiting the development,
stockpiling, or use of chemical weapons by any State Party
or person within a State Party’s jurisdiction. Arts. I, II,
VII. It also established an elaborate reporting process
requiring State Parties to destroy chemical weapons under
their control and submit to inspection and monitoring by
an international organization based in The Hague, Neth-
erlands. Arts. VIII, IX.
    The Convention provides:
4                 BOND v. UNITED STATES

                      Opinion of the Court

    “(1) Each State Party to this Convention undertakes
    never under any circumstances:
      “(a) To develop, produce, otherwise acquire, stock-
    pile or retain chemical weapons, or transfer, directly
    or indirectly, chemical weapons to anyone;
      “(b) To use chemical weapons;
      “(c) To engage in any military preparations to use
    chemical weapons;
      “(d) To assist, encourage or induce, in any way, any-
    one to engage in any activity prohibited to a State
    Party under this Convention.” Art. I, id., at 319.
“Chemical Weapons” are defined in relevant part as
“[t]oxic chemicals and their precursors, except where
intended for purposes not prohibited under this Conven-
tion, as long as the types and quantities are consistent
with such purposes.” Art. II(1)(a), ibid. “Toxic Chemical,”
in turn, is defined as “Any chemical which through its
chemical action on life processes can cause death, tempo-
rary incapacitation or permanent harm to humans or
animals. This includes all such chemicals, regardless of
their origin or of their method of production, and regard-
less of whether they are produced in facilities, in muni-
tions or elsewhere.” Art. II(2), id., at 320. “Purposes Not
Prohibited Under this Convention” means “[i]ndustrial,
agricultural, research, medical, pharmaceutical or other
peaceful purposes,” Art. II(9)(a), id., at 322, and other
specific purposes not at issue here, Arts. II(9)(b)–(d).
   Although the Convention is a binding international
agreement, it is “not self-executing.” W. Krutzsch & R.
Trapp, A Commentary on the Chemical Weapons Conven-
tion 109 (1994). That is, the Convention creates obliga-
tions only for State Parties and “does not by itself give rise
to domestically enforceable federal law” absent “imple-
menting legislation passed by Congress.” Medellín v.
Texas, 552 U. S. 491, 505, n. 2 (2008). It instead provides
                 Cite as: 572 U. S. ____ (2014)            5

                     Opinion of the Court

that “[e]ach State Party shall, in accordance with its con-
stitutional processes, adopt the necessary measures to
implement its obligations under this Convention.”
Art. VII(1), 1974 U. N. T. S. 331. “In particular,” each
State Party shall “[p]rohibit natural and legal persons
anywhere . . . under its jurisdiction . . . from undertaking
any activity prohibited to a State Party under this Con-
vention, including enacting penal legislation with respect
to such activity.” Art. VII (1)(a), id., at 331–332.
  Congress gave the Convention domestic effect in 1998
when it passed the Chemical Weapons Convention Imple-
mentation Act. See 112 Stat. 2681–856. The Act closely
tracks the text of the treaty: It forbids any person know-
ingly “to develop, produce, otherwise acquire, transfer
directly or indirectly, receive, stockpile, retain, own, pos-
sess, or use, or threaten to use, any chemical weapon.” 18
U. S. C. §229(a)(1). It defines “chemical weapon” in rele-
vant part as “[a] toxic chemical and its precursors, except
where intended for a purpose not prohibited under this
chapter as long as the type and quantity is consistent with
such a purpose.” §229F(1)(A). “Toxic chemical,” in turn, is
defined in general as “any chemical which through its
chemical action on life processes can cause death, tempo-
rary incapacitation or permanent harm to humans or
animals. The term includes all such chemicals, regardless
of their origin or of their method of production, and re-
gardless of whether they are produced in facilities, in
munitions or elsewhere.” §229F(8)(A). Finally, “purposes
not prohibited by this chapter” is defined as “[a]ny peace-
ful purpose related to an industrial, agricultural, research,
medical, or pharmaceutical activity or other activity,” and
other specific purposes. §229F(7). A person who violates
section 229 may be subject to severe punishment: impris-
onment “for any term of years,” or if a victim’s death re-
sults, the death penalty or imprisonment “for life.”
§229A(a).
6                BOND v. UNITED STATES

                     Opinion of the Court

                               B
  Petitioner Carol Anne Bond is a microbiologist from
Lansdale, Pennsylvania. In 2006, Bond’s closest friend,
Myrlinda Haynes, announced that she was pregnant.
When Bond discovered that her husband was the child’s
father, she sought revenge against Haynes. Bond stole a
quantity of 10-chloro-10H-phenoxarsine (an arsenic-based
compound) from her employer, a chemical manufacturer.
She also ordered a vial of potassium dichromate (a chemi-
cal commonly used in printing photographs or cleaning
laboratory equipment) on Amazon.com. Both chemicals
are toxic to humans and, in high enough doses, potentially
lethal. It is undisputed, however, that Bond did not in-
tend to kill Haynes. She instead hoped that Haynes would
touch the chemicals and develop an uncomfortable rash.
  Between November 2006 and June 2007, Bond went to
Haynes’s home on at least 24 occasions and spread the
chemicals on her car door, mailbox, and door knob. These
attempted assaults were almost entirely unsuccessful.
The chemicals that Bond used are easy to see, and Haynes
was able to avoid them all but once. On that occasion,
Haynes suffered a minor chemical burn on her thumb,
which she treated by rinsing with water. Haynes repeat-
edly called the local police to report the suspicious sub-
stances, but they took no action. When Haynes found
powder on her mailbox, she called the police again, who
told her to call the post office. Haynes did so, and postal
inspectors placed surveillance cameras around her home.
The cameras caught Bond opening Haynes’s mailbox,
stealing an envelope, and stuffing potassium dichromate
inside the muffler of Haynes’s car.
  Federal prosecutors naturally charged Bond with two
counts of mail theft, in violation of 18 U. S. C. §1708.
More surprising, they also charged her with two counts
of possessing and using a chemical weapon, in violation
of section 229(a). Bond moved to dismiss the chemical
                 Cite as: 572 U. S. ____ (2014)           7

                     Opinion of the Court

weapon counts on the ground that section 229 exceeded
Congress’s enumerated powers and invaded powers re-
served to the States by the Tenth Amendment. The District
Court denied Bond’s motion. She then entered a condi-
tional guilty plea that reserved her right to appeal. The
District Court sentenced Bond to six years in federal
prison plus five years of supervised release, and ordered
her to pay a $2,000 fine and $9,902.79 in restitution.
   Bond appealed, raising a Tenth Amendment challenge
to her conviction. The Government contended that Bond
lacked standing to bring such a challenge. The Court of
Appeals for the Third Circuit agreed. We granted certio-
rari, the Government confessed error, and we reversed.
We held that, in a proper case, an individual may “assert
injury from governmental action taken in excess of the
authority that federalism defines.” Bond v. United States,
564 U. S. ___, ___ (2011) (Bond I) (slip op., at 8). We “ex-
presse[d] no view on the merits” of Bond’s constitutional
challenge. Id., at ___ (slip op., at 14).
   On remand, Bond renewed her constitutional argument.
She also argued that section 229 does not reach her con-
duct because the statute’s exception for the use of chemi-
cals for “peaceful purposes” should be understood in con-
tradistinction to the “warlike” activities that the
Convention was primarily designed to prohibit. Bond
argued that her conduct, though reprehensible, was not at
all “warlike.” The Court of Appeals rejected this argu-
ment. 681 F. 3d 149 (CA3 2012). The court acknowledged
that the Government’s reading of section 229 would render
the statute “striking” in its “breadth” and turn every
“kitchen cupboard and cleaning cabinet in America into a
potential chemical weapons cache.” Id., at 154, n. 7. But
the court nevertheless held that Bond’s use of “ ‘highly
toxic chemicals with the intent of harming Haynes’ can
hardly be characterized as ‘peaceful’ under that word’s
commonly understood meaning.” Id., at 154 (citation
8                 BOND v. UNITED STATES

                     Opinion of the Court

omitted).
   The Third Circuit also rejected Bond’s constitutional
challenge to her conviction, holding that section 229 was
“necessary and proper to carry the Convention into effect.”
Id., at 162. The Court of Appeals relied on this Court’s
opinion in Missouri v. Holland, 252 U. S. 416 (1920),
which stated that “[i]f the treaty is valid there can be no
dispute about the validity of the statute” that implements
it “as a necessary and proper means to execute the powers
of the Government,” id., at 432.
   We again granted certiorari, 568 U. S. ___ (2013).
                              II
  In our federal system, the National Government pos-
sesses only limited powers; the States and the people
retain the remainder. The States have broad authority to
enact legislation for the public good—what we have often
called a “police power.” United States v. Lopez, 514 U. S.
549, 567 (1995). The Federal Government, by contrast,
has no such authority and “can exercise only the powers
granted to it,” McCulloch v. Maryland, 4 Wheat. 316, 405
(1819), including the power to make “all Laws which shall
be necessary and proper for carrying into Execution” the
enumerated powers, U. S. Const., Art. I, §8, cl. 18. For
nearly two centuries it has been “clear” that, lacking a
police power, “Congress cannot punish felonies generally.”
Cohens v. Virginia, 6 Wheat. 264, 428 (1821). A criminal
act committed wholly within a State “cannot be made an
offence against the United States, unless it have some
relation to the execution of a power of Congress, or to some
matter within the jurisdiction of the United States.”
United States v. Fox, 95 U. S. 670, 672 (1878).
  The Government frequently defends federal criminal
legislation on the ground that the legislation is authorized
pursuant to Congress’s power to regulate interstate com-
merce. In this case, however, the Court of Appeals held
                 Cite as: 572 U. S. ____ (2014)            9

                     Opinion of the Court

that the Government had explicitly disavowed that argu-
ment before the District Court. 681 F. 3d, at 151, n. 1. As
a result, in this Court the parties have devoted significant
effort to arguing whether section 229, as applied to Bond’s
offense, is a necessary and proper means of executing the
National Government’s power to make treaties. U. S.
Const., Art. II, §2, cl. 2. Bond argues that the lower
court’s reading of Missouri v. Holland would remove all
limits on federal authority, so long as the Federal Gov-
ernment ratifies a treaty first. She insists that to effec-
tively afford the Government a police power whenever it
implements a treaty would be contrary to the Framers’
careful decision to divide power between the States and
the National Government as a means of preserving liberty.
To the extent that Holland authorizes such usurpation of
traditional state authority, Bond says, it must be either
limited or overruled.
   The Government replies that this Court has never held
that a statute implementing a valid treaty exceeds Con-
gress’s enumerated powers. To do so here, the Govern-
ment says, would contravene another deliberate choice of
the Framers: to avoid placing subject matter limitations
on the National Government’s power to make treaties.
And it might also undermine confidence in the United
States as an international treaty partner.
   Notwithstanding this debate, it is “a well-established
principle governing the prudent exercise of this Court’s
jurisdiction that normally the Court will not decide a
constitutional question if there is some other ground upon
which to dispose of the case.” Escambia County v. Mc-
Millan, 466 U. S. 48, 51 (1984) (per curiam); see also
Ashwander v. TVA, 297 U. S. 288, 347 (1936) (Brandeis,
J., concurring). Bond argues that section 229 does not
cover her conduct. So we consider that argument first.
10                BOND v. UNITED STATES


                     Opinion of the Court 


                             III

  Section 229 exists to implement the Convention, so we
begin with that international agreement. As explained,
the Convention’s drafters intended for it to be a compre-
hensive ban on chemical weapons. But even with its
broadly worded definitions, we have doubts that a treaty
about chemical weapons has anything to do with Bond’s
conduct. The Convention, a product of years of worldwide
study, analysis, and multinational negotiation, arose in
response to war crimes and acts of terrorism. See Kenyon
& Feakes 6. There is no reason to think the sovereign
nations that ratified the Convention were interested in
anything like Bond’s common law assault.
  Even if the treaty does reach that far, nothing prevents
Congress from implementing the Convention in the same
manner it legislates with respect to innumerable other
matters—observing the Constitution’s division of respon-
sibility between sovereigns and leaving the prosecution of
purely local crimes to the States. The Convention, after
all, is agnostic between enforcement at the state versus
federal level: It provides that “[e]ach State Party shall, in
accordance with its constitutional processes, adopt the
necessary measures to implement its obligations under
this Convention.” Art. VII(1), 1974 U. N. T. S. 331 (em-
phasis added); see also Tabassi, National Implementation:
Article VII, in Kenyon & Feakes 205, 207 (“Since the
creation of national law, the enforcement of it and the
structure and administration of government are all sover-
eign acts reserved exclusively for [State Parties], it is not
surprising that the Convention is so vague on the critical
matter of national implementation.”).
  Fortunately, we have no need to interpret the scope of
the Convention in this case. Bond was prosecuted under
section 229, and the statute—unlike the Convention—
must be read consistent with principles of federalism
inherent in our constitutional structure.
                      Cite as: 572 U. S. ____ (2014)                  11

                          Opinion of the Court

                             A
   In the Government’s view, the conclusion that Bond
“knowingly” “use[d]” a “chemical weapon” in violation of
section 229(a) is simple: The chemicals that Bond placed
on Haynes’s home and car are “toxic chemical[s]” as de-
fined by the statute, and Bond’s attempt to assault
Haynes was not a “peaceful purpose.” §§229F(1), (8), (7).
The problem with this interpretation is that it would
“dramatically intrude[ ] upon traditional state criminal
jurisdiction,” and we avoid reading statutes to have such
reach in the absence of a clear indication that they do.
United States v. Bass, 404 U. S. 336, 350 (1971).
   Part of a fair reading of statutory text is recognizing
that “Congress legislates against the backdrop” of certain
unexpressed presumptions. EEOC v. Arabian American
Oil Co., 499 U. S. 244, 248 (1991). As Justice Frankfurter
put it in his famous essay on statutory interpretation,
correctly reading a statute “demands awareness of certain
presuppositions.” Some Reflections on the Reading of
Statutes, 47 Colum. L. Rev. 527, 537 (1947). For example,
we presume that a criminal statute derived from the
common law carries with it the requirement of a culpable
mental state—even if no such limitation appears in the
text—unless it is clear that the Legislature intended to
impose strict liability. United States v. United States
Gypsum Co., 438 U. S. 422, 437 (1978). To take another
example, we presume, absent a clear statement from
Congress, that federal statutes do not apply outside the
United States. Morrison v. National Australia Bank Ltd.,
561 U. S. 247, 255 (2010). So even though section 229,
read on its face, would cover a chemical weapons crime if
committed by a U. S. citizen in Australia, we would not
apply the statute to such conduct absent a plain statement
from Congress.1 The notion that some things “go without
——————
 1 Congress   has in fact included just such a plain statement in section
12                    BOND v. UNITED STATES

                          Opinion of the Court

saying” applies to legislation just as it does to everyday
life.
    Among the background principles of construction that
our cases have recognized are those grounded in the rela-
tionship between the Federal Government and the States
under our Constitution. It has long been settled, for ex-
ample, that we presume federal statutes do not abrogate
state sovereign immunity, Atascadero State Hospital v.
Scanlon, 473 U. S. 234, 243 (1985), impose obligations on
the States pursuant to section 5 of the Fourteenth
Amendment, Pennhurst State School and Hospital v.
Halderman, 451 U. S. 1, 16–17 (1981), or preempt state
law, Rice v. Santa Fe Elevator Corp., 331 U. S. 218, 230
(1947).
    Closely related to these is the well-established principle
that “ ‘it is incumbent upon the federal courts to be certain
of Congress’ intent before finding that federal law over-
rides’ ” the “usual constitutional balance of federal and
state powers.” Gregory v. Ashcroft, 501 U. S. 452, 460
(1991) (quoting Atascadero, supra, at 243). To quote
Frankfurter again, if the Federal Government would
“ ‘radically readjust[ ] the balance of state and national
authority, those charged with the duty of legislating [must
be] reasonably explicit’ ” about it. BFP v. Resolution Trust
Corporation, 511 U. S. 531, 544 (1994) (quoting Some
Reflections, supra, at 539–540; second alteration in origi-
nal). Or as explained by Justice Marshall, when legisla-
tion “affect[s] the federal balance, the requirement of clear
statement assures that the legislature has in fact faced,
and intended to bring into issue, the critical matters in-
volved in the judicial decision.” Bass, supra, at 349.

——————
229(c)(2): “Conduct prohibited by [section 229(a)] is within the jurisdic-
tion of the United States if the prohibited conduct . . . takes place
outside of the United States and is committed by a national of the
United States.”
                  Cite as: 572 U. S. ____ (2014)            13

                      Opinion of the Court

   We have applied this background principle when con-
struing federal statutes that touched on several areas of
traditional state responsibility. See Gregory, supra, at 460
(qualifications for state officers); BFP, supra, at 544 (titles
to real estate); Solid Waste Agency of Northern Cook Cty.
v. Army Corps of Engineers, 531 U. S. 159, 174 (2001)
(land and water use). Perhaps the clearest example of
traditional state authority is the punishment of local
criminal activity. United States v. Morrison, 529 U. S.
598, 618 (2000). Thus, “we will not be quick to assume
that Congress has meant to effect a significant change in
the sensitive relation between federal and state criminal
jurisdiction.” Bass, 404 U. S., at 349.
   In Bass, we interpreted a statute that prohibited any
convicted felon from “ ‘receiv[ing], possess[ing], or
transport[ing] in commerce or affecting commerce . . . any
firearm.’ ” Id., at 337. The Government argued that the
statute barred felons from possessing all firearms and
that it was not necessary to demonstrate a connection to
interstate commerce. We rejected that reading, which
would “render[ ] traditionally local criminal conduct a
matter for federal enforcement and would also involve a
substantial extension of federal police resources.” Id., at
350. We instead read the statute more narrowly to re-
quire proof of a connection to interstate commerce in every
case, thereby “preserv[ing] as an element of all the of-
fenses a requirement suited to federal criminal jurisdic-
tion alone.” Id., at 351.
   Similarly, in Jones v. United States, 529 U. S. 848, 850
(2000), we confronted the question whether the federal
arson statute, which prohibited burning “ ‘any . . . property
used in interstate or foreign commerce or in any activity
affecting interstate or foreign commerce,’ ” reached an
owner-occupied private residence. Once again we rejected
the Government’s “expansive interpretation,” under which
“hardly a building in the land would fall outside the fed-
14                    BOND v. UNITED STATES

                          Opinion of the Court

eral statute’s domain.” Id., at 857. We instead held that the
statute was “most sensibly read” more narrowly to reach
only buildings used in “active employment for commercial
purposes.” Id., at 855. We noted that “arson is a para-
digmatic common-law state crime,” id., at 858, and that
the Government’s proposed broad reading would “ ‘signifi-
cantly change[ ] the federal-state balance,’ ” ibid. (quoting
Bass, 404 U. S., at 349), “mak[ing] virtually every arson in
the country a federal offense,” 529 U. S., at 859.
  These precedents make clear that it is appropriate to
refer to basic principles of federalism embodied in the
Constitution to resolve ambiguity in a federal statute. In
this case, the ambiguity derives from the improbably
broad reach of the key statutory definition given the
term—“chemical weapon”—being defined; the deeply
serious consequences of adopting such a boundless read-
ing; and the lack of any apparent need to do so in light of
the context from which the statute arose—a treaty about
chemical warfare and terrorism. We conclude that, in this
curious case, we can insist on a clear indication that Con-
gress meant to reach purely local crimes, before interpret-
ing the statute’s expansive language in a way that in-
trudes on the police power of the States. See Bass, supra,
at 349.2
——————
  2 JUSTICE SCALIA contends that the relevance of Bass and Jones to this

case is “entirely made up,” post, at 3 (opinion concurring in judgment),
but not because he disagrees with interpreting statutes in light of
principles of federalism. Rather, he says that Bass was a case where
the statute was unclear. We agree; we simply think the statute in this
case is also subject to construction, for the reasons given. As for Jones,
JUSTICE SCALIA argues that the discussion of federalism in that case
was beside the point. Post, at 4. We do not read Jones that way; the
Court adopted the “most sensibl[e] read[ing]” of the statute, 529 U. S.,
at 855, which suggests that other sensible readings were possible. In
arriving at its fair reading of the statute, the Court considered the
dramatic extent to which the Government’s broader interpretation
would have expanded “the federal statute’s domain.” Id., at 857. We do
                  Cite as: 572 U. S. ____ (2014) 
          15

                      Opinion of the Court 


                                B

   We do not find any such clear indication in section 229.
“Chemical weapon” is the key term that defines the stat-
ute’s reach, and it is defined extremely broadly. But that
general definition does not constitute a clear statement
that Congress meant the statute to reach local criminal
conduct.
   In fact, a fair reading of section 229 suggests that it does
not have as expansive a scope as might at first appear. To
begin, as a matter of natural meaning, an educated user of
English would not describe Bond’s crime as involving a
“chemical weapon.” Saying that a person “used a chemical
weapon” conveys a very different idea than saying the
person “used a chemical in a way that caused some harm.”
The natural meaning of “chemical weapon” takes account
of both the particular chemicals that the defendant used
and the circumstances in which she used them.
   When used in the manner here, the chemicals in this
case are not of the sort that an ordinary person would
associate with instruments of chemical warfare. The
substances that Bond used bear little resemblance to the
deadly toxins that are “of particular danger to the objec-
tives of the Convention.” Why We Need a Chemical
Weapons Convention and an OPCW, in Kenyon & Feakes
17 (describing the Convention’s Annex on Chemicals, a
nonexhaustive list of covered substances that are subject
to special regulation). More to the point, the use of some-
thing as a “weapon” typically connotes “[a]n instrument of
offensive or defensive combat,” Webster’s Third New
International Dictionary 2589 (2002), or “[a]n instrument
of attack or defense in combat, as a gun, missile, or
sword,” American Heritage Dictionary 2022 (3d ed. 1992).
But no speaker in natural parlance would describe Bond’s
feud-driven act of spreading irritating chemicals on
——————
the same here.
16                BOND v. UNITED STATES

                      Opinion of the Court

Haynes’s door knob and mailbox as “combat.” Nor do the
other circumstances of Bond’s offense—an act of revenge
born of romantic jealousy, meant to cause discomfort, that
produced nothing more than a minor thumb burn—
suggest that a chemical weapon was deployed in Norris-
town, Pennsylvania. Potassium dichromate and 10-chloro-
10H-phenoxarsine might be chemical weapons if used, say,
to poison a city’s water supply. But Bond’s crime is worlds
apart from such hypotheticals, and covering it would give
the statute a reach exceeding the ordinary meaning of the
words Congress wrote.
  In settling on a fair reading of a statute, it is not un-
usual to consider the ordinary meaning of a defined term,
particularly when there is dissonance between that ordi-
nary meaning and the reach of the definition. In Johnson
v. United States, 559 U. S. 133, 136 (2010), for example,
we considered the statutory term “ ‘violent felony,’ ” which
the Armed Career Criminal Act defined in relevant part as
an offense that “ ‘has as an element the use . . . of physical
force against the person of another.’ ” Although “physical
force against . . . another” might have meant any force,
however slight, we thought it “clear that in the context of
a statutory definition of ‘violent felony,’ the phrase ‘physi-
cal force’ means violent force—that is, force capable of
causing physical pain or injury to another person.” Id., at
140. The ordinary meaning of “chemical weapon” plays a
similar limiting role here.
  The Government would have us brush aside the ordi-
nary meaning and adopt a reading of section 229 that
would sweep in everything from the detergent under the
kitchen sink to the stain remover in the laundry room.
Yet no one would ordinarily describe those substances as
“chemical weapons.”       The Government responds that
because Bond used “specialized, highly toxic” (though
legal) chemicals, “this case presents no occasion to address
whether Congress intended [section 229] to apply to com-
                  Cite as: 572 U. S. ____ (2014)             17

                      Opinion of the Court

mon household substances.” Brief for United States 13,
n. 3. That the statute would apply so broadly, however, is
the inescapable conclusion of the Government’s position:
Any parent would be guilty of a serious federal offense—
possession of a chemical weapon—when, exasperated by
the children’s repeated failure to clean the goldfish tank,
he considers poisoning the fish with a few drops of vine-
gar. We are reluctant to ignore the ordinary meaning of
“chemical weapon” when doing so would transform a
statute passed to implement the international Convention
on Chemical Weapons into one that also makes it a federal
offense to poison goldfish. That would not be a “realistic
assessment[ ] of congressional intent.” Post, at 6 (SCALIA,
J., concurring in judgment).
   In light of all of this, it is fully appropriate to apply the
background assumption that Congress normally preserves
“the constitutional balance between the National Govern-
ment and the States.” Bond I, 564 U. S., at ___ (slip op., at
10). That assumption is grounded in the very structure of
the Constitution. And as we explained when this case was
first before us, maintaining that constitutional balance is
not merely an end unto itself. Rather, “[b]y denying any
one government complete jurisdiction over all the concerns
of public life, federalism protects the liberty of the individ-
ual from arbitrary power.” Ibid.
   The Government’s reading of section 229 would “ ‘alter
sensitive federal-state relationships,’ ” convert an astonish-
ing amount of “traditionally local criminal conduct” into “a
matter for federal enforcement,” and “involve a substantial
extension of federal police resources.” Bass, 404 U. S., at
349–350. It would transform the statute from one whose
core concerns are acts of war, assassination, and terrorism
into a massive federal anti-poisoning regime that reaches
the simplest of assaults. As the Government reads section
229, “hardly” a poisoning “in the land would fall outside
the federal statute’s domain.” Jones, 529 U. S., at 857. Of
18                BOND v. UNITED STATES

                     Opinion of the Court

course Bond’s conduct is serious and unacceptable—and
against the laws of Pennsylvania. But the background
principle that Congress does not normally intrude upon
the police power of the States is critically important. In
light of that principle, we are reluctant to conclude that
Congress meant to punish Bond’s crime with a federal
prosecution for a chemical weapons attack.
   In fact, with the exception of this unusual case, the
Federal Government itself has not looked to section 229 to
reach purely local crimes. The Government has identified
only a handful of prosecutions that have been brought
under this section. Brief in Opposition 27, n. 5. Most of
those involved either terrorist plots or the possession of
extremely dangerous substances with the potential to
cause severe harm to many people. See United States v.
Ghane, 673 F. 3d 771 (CA8 2012) (defendant possessed
enough potassium cyanide to kill 450 people); United
States v. Crocker, 260 Fed. Appx. 794 (CA6 2008) (defend-
ant attempted to acquire VX nerve gas and chlorine gas as
part of a plot to attack a federal courthouse); United States
v. Krar, 134 Fed. Appx. 662 (CA5 2005) (per curiam) (de-
fendant possessed sodium cyanide); United States v. Fries,
2012 WL 689157 (D Ariz., Feb. 28, 2012) (defendant set off
a homemade chlorine bomb in the victim’s driveway,
requiring evacuation of a residential neighborhood). The
Federal Government undoubtedly has a substantial inter-
est in enforcing criminal laws against assassination, ter-
rorism, and acts with the potential to cause mass suffer-
ing.     Those crimes have not traditionally been left
predominantly to the States, and nothing we have said
here will disrupt the Government’s authority to prosecute
such offenses.
   It is also clear that the laws of the Commonwealth of
Pennsylvania (and every other State) are sufficient to
prosecute Bond. Pennsylvania has several statutes that
would likely cover her assault. See 18 Pa. Cons. Stat.
                     Cite as: 572 U. S. ____ (2014)                  19

                         Opinion of the Court

§§2701 (2012) (simple assault), 2705 (reckless endanger-
ment), 2709 (harassment).3 And state authorities regularly
enforce these laws in poisoning cases. See, e.g., Gamiz,
Family Survives Poisoned Burritos, Allentown, Pa., Morn-
ing Call, May 18, 2013 (defendant charged with assault,
reckless endangerment, and harassment for feeding burri-
tos poisoned with prescription medication to her husband
and daughter); Cops: Man Was Poisoned Over 3 Years,
Harrisburg, Pa., Patriot News, Aug. 12, 2012, p. A11
(defendant charged with assault and reckless endanger-
ment for poisoning a man with eye drops over three years
so that “he would pay more attention to her”).
  The Government objects that Pennsylvania authorities
charged Bond with only a minor offense based on her
“harassing telephone calls and letters,” Bond I, 564 U. S.,
at ___ (slip op., at 2), and declined to prosecute her for
assault. But we have traditionally viewed the exercise of
state officials’ prosecutorial discretion as a valuable fea-
ture of our constitutional system. See Bordenkircher v.
Hayes, 434 U. S. 357, 364 (1978). And nothing in the
Convention shows a clear intent to abrogate that feature.
Prosecutorial discretion involves carefully weighing the
benefits of a prosecution against the evidence needed to
convict, the resources of the public fisc, and the public
policy of the State. Here, in its zeal to prosecute Bond, the
Federal Government has “displaced” the “public policy of
the Commonwealth of Pennsylvania, enacted in its capaci-
ty as sovereign,” that Bond does not belong in prison for a
chemical weapons offense. Bond I, supra, at ___ (slip op.,
at 12); see also Jones, supra, at 859 (Stevens, J., concur-
ring) (federal prosecution of a traditionally local crime
——————
  3 Pennsylvania also prohibits using “a weapon of mass destruction,”

including a “chemical agent.” 18 Pa. Cons. Stat. §§2716(a), (i). Just as
we conclude that Bond’s offense cannot be fairly described as the use of
a chemical weapon, Pennsylvania authorities apparently determined
that her crime did not involve a “weapon of mass destruction.”
20                BOND v. UNITED STATES

                     Opinion of the Court

“illustrates how a criminal law like this may effectively
displace a policy choice made by the State”).
   As we have explained, “Congress has traditionally been
reluctant to define as a federal crime conduct readily
denounced as criminal by the States.” Bass, 404 U. S., at
349. There is no clear indication of a contrary approach
here. Section 229 implements the Convention, but Bond’s
crime could hardly be more unlike the uses of mustard gas
on the Western Front or nerve agents in the Iran-Iraq war
that form the core concerns of that treaty. See Kenyon &
Feakes 6. There are no life-sized paintings of Bond’s rival
washing her thumb. And there are no apparent interests
of the United States Congress or the community of nations
in seeing Bond end up in federal prison, rather than dealt
with (like virtually all other criminals in Pennsylvania) by
the State. The Solicitor General acknowledged as much at
oral argument. See Tr. of Oral Arg. 47 (“I don’t think
anybody would say [that] whether or not Ms. Bond is
prosecuted would give rise to an international incident”).
   This case is unusual, and our analysis is appropriately
limited. Our disagreement with our colleagues reduces to
whether section 229 is “utterly clear.” Post, at 5 (SCALIA,
J., concurring in judgment). We think it is not, given that
the definition of “chemical weapon” in a particular case
can reach beyond any normal notion of such a weapon,
that the context from which the statute arose demon-
strates a much more limited prohibition was intended, and
that the most sweeping reading of the statute would fun-
damentally upset the Constitution’s balance between
national and local power. This exceptional convergence of
factors gives us serious reason to doubt the Government’s
expansive reading of section 229, and calls for us to inter-
pret the statute more narrowly.
   In sum, the global need to prevent chemical warfare
does not require the Federal Government to reach into the
kitchen cupboard, or to treat a local assault with a chemi-
                  Cite as: 572 U. S. ____ (2014)           21

                      Opinion of the Court

cal irritant as the deployment of a chemical weapon.
There is no reason to suppose that Congress—in imple-
menting the Convention on Chemical Weapons—thought
otherwise.
                        *     *     *
   The Convention provides for implementation by each
ratifying nation “in accordance with its constitutional
processes.” Art. VII(1), 1974 U. N. T. S. 331. As James
Madison explained, the constitutional process in our
“compound republic” keeps power “divided between two
distinct governments.” The Federalist No. 51, p. 323 (C.
Rossiter ed. 1961). If section 229 reached Bond’s conduct,
it would mark a dramatic departure from that constitu-
tional structure and a serious reallocation of criminal law
enforcement authority between the Federal Government
and the States. Absent a clear statement of that purpose,
we will not presume Congress to have authorized such a
stark intrusion into traditional state authority.
   The judgment of the Court of Appeals is reversed, and
the case is remanded for further proceedings consistent
with this opinion.
                                             It is so ordered.
                     Cite as: 572 U. S. ____ (2014)                    1

                   SCALIA, J., concurring in judgment

SUPREME COURT OF THE UNITED STATES
                              _________________

                              No. 12–158
                              _________________


     CAROL ANNE BOND, PETITIONER v. UNITED

                   STATES 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE THIRD CIRCUIT

                             [June 2, 2014]


    JUSTICE SCALIA, with whom JUSTICE THOMAS joins, and
with whom JUSTICE ALITO joins as to Part I, concurring in
the judgment.
    Somewhere in Norristown, Pennsylvania, a husband’s
paramour suffered a minor thumb burn at the hands of a
betrayed wife. The United States Congress—“every where
extending the sphere of its activity, and drawing all power
into its impetuous vortex”1—has made a federal case out of
it. What are we to do?
    It is the responsibility of “the legislature, not the Court,
. . . to define a crime, and ordain its punishment.” United
States v. Wiltberger, 5 Wheat. 76, 95 (1820) (Marshall,
C. J., for the Court). And it is “emphatically the province
and duty of the judicial department to say what the law
[including the Constitution] is.” Marbury v. Madison, 1
Cranch 137, 177 (1803) (same). Today, the Court shirks
its job and performs Congress’s. As sweeping and unset-
tling as the Chemical Weapons Convention Implementa-
tion Act of 1998 may be, it is clear beyond doubt that it
covers what Bond did; and we have no authority to amend
it. So we are forced to decide—there is no way around
it—whether the Act’s application to what Bond did was
——————
  1 The Federalist No. 48, p. 333 (J. Cooke ed. 1961) (J. Madison) (here-

inafter The Federalist).
2                 BOND v. UNITED STATES

               SCALIA, J., concurring in judgment

constitutional.
  I would hold that it was not, and for that reason would
reverse the judgment of the Court of Appeals for the Third
Circuit.

                 I. The Statutory Question
            A. Unavoidable Meaning of the Text
   The meaning of the Act is plain. No person may know-
ingly “develop, produce, otherwise acquire, transfer directly
or indirectly, receive, stockpile, retain, own, possess, or
use, or threaten to use, any chemical weapon.” 18 U. S. C.
§229(a)(1). A “chemical weapon” is “[a] toxic chemical and
its precursors, except where intended for a purpose not
prohibited under this chapter as long as the type and
quantity is consistent with such a purpose.” §229F(1)(A).
A “toxic chemical” is “any chemical which through its
chemical action on life processes can cause death, tempo-
rary incapacitation or permanent harm to humans or
animals. The term includes all such chemicals, regardless
of their origin or of their method of production, and re-
gardless of whether they are produced in facilities, in
munitions or elsewhere.” §229F(8)(A). A “purpose not
prohibited” is “[a]ny peaceful purpose related to an indus-
trial, agricultural, research, medical, or pharmaceutical
activity or other activity.” §229F(7)(A).
   Applying those provisions to this case is hardly compli-
cated.    Bond possessed and used “chemical[s] which
through [their] chemical action on life processes can cause
death, temporary incapacitation or permanent harm.”
Thus, she possessed “toxic chemicals.” And, because they
were not possessed or used only for a “purpose not prohib-
ited,” §229F(1)(A), they were “chemical weapons.” Ergo,
Bond violated the Act. End of statutory analysis, I would
                     Cite as: 572 U. S. ____ (2014)                    3

                   SCALIA, J., concurring in judgment

have thought.2
  The Court does not think the interpretive exercise so
simple. But that is only because its result-driven antitex-
tualism befogs what is evident.
                B. The Court’s Interpretation
   The Court’s account of the clear-statement rule reads
like a really good lawyer’s brief for the wrong side, relying
on cases that are so close to being on point that someone
eager to reach the favored outcome might swallow them.
The relevance to this case of United States v. Bass, 404
U. S. 336 (1971), and Jones v. United States, 529 U. S. 848
(2000), is, in truth, entirely made up. In Bass, we had to
decide whether a statute forbidding “ ‘receiv[ing], pos-
sess[ing], or transport[ing] in commerce or affecting com-
merce . . . any firearm’ ” prohibited possessing a gun that
lacked any connection to interstate commerce. 404 U. S., at
337–339. Though the Court relied in part on a federalism-
inspired interpretive presumption, it did so only after it
had found, in Part I of the opinion, applying traditional
interpretive tools, that the text in question was ambigu-
ous, id., at 339–347. Adopting in Part II the narrower of
the two possible readings, we said that “unless Congress
conveys its purpose clearly, it will not be deemed to have
significantly changed the federal-state balance.” Id., at
349 (emphasis added). Had Congress “convey[ed] its
purpose clearly” by enacting a clear and even sweeping
statute, the presumption would not have applied.
——————
  2 Petitioner offers one textual argument that the Court does not con-

sider. She argues that the exception for “peaceful purposes” is best
understood as a term of art meaning roughly any purpose that is not
“warlike.”    Brief for Petitioner 50–57.      Though that reading is
more defensible than the Court’s, the Act will not bear it. If “peaceful”
meant “nonwarlike,” the statute’s exception for “any individual self-
defense device, including . . . pepper spray or chemical mace,” §229C—
the prosaic uses of which are surely nonwarlike—would have been
unnecessary.
4                     BOND v. UNITED STATES

                   SCALIA, J., concurring in judgment

    Jones is also irrelevant. To determine whether an owner-
occupied private residence counted as a “ ‘property used
in interstate or foreign commerce or in any activity affect-
ing interstate or foreign commerce’ ” under the federal
arson statute, 529 U. S., at 850–851, our opinion examined
not the federal-jurisdiction-expanding consequences of
answering yes but rather the ordinary meaning of the
words—and answered no, id., at 855–857. Then, in a
separate part of the opinion, we observed that our reading
was consistent with the principle that we should adopt a
construction that avoids “grave and doubtful constitutional
questions,” id., at 857, and, quoting Bass, the principle
that Congress must convey its purpose clearly before its
laws will be “ ‘deemed to have significantly changed the
federal-state balance,’ ” 529 U. S., at 858. To say that the
best reading of the text conformed to those principles is
not to say that those principles can render clear text
ambiguous.3
    The latter is what the Court says today. Inverting Bass
and Jones, it starts with the federalism-related conse-
quences of the statute’s meaning and reasons backwards,
holding that, if the statute has what the Court considers a
disruptive effect on the “federal-state balance” of criminal
jurisdiction, ante, at 14, that effect causes the text, even if
clear on its face, to be ambiguous. Just ponder what the
Court says: “[The Act’s] ambiguity derives from the im-
probably broad reach of the key statutory definition . . .
the deeply serious consequences of adopting such a bound-
less reading; and the lack of any apparent need to do so
. . . .” Ibid. (emphasis added). Imagine what future courts
——————
  3 Other cases in the Bass line confirm that broad text “need only be

plain to anyone reading [it]” in order to be given its obvious meaning.
Salinas v. United States, 522 U. S. 52, 60 (1997) (internal quotation
marks omitted); see also Pennsylvania Dept. of Corrections v. Yeskey,
524 U. S. 206, 209 (1998); cf. United States v. Lopez, 514 U. S. 549, 562
(1995).
                  Cite as: 572 U. S. ____ (2014)             5

                SCALIA, J., concurring in judgment

can do with that judge-empowering principle: Whatever
has improbably broad, deeply serious, and apparently
unnecessary consequences . . . is ambiguous!
   The same skillful use of oh-so-close-to-relevant cases
characterizes the Court’s pro forma attempt to find ambi-
guity in the text itself, specifically, in the term “[c]hemical
weapon.” The ordinary meaning of weapon, the Court
says, is an instrument of combat, and “no speaker in natu-
ral parlance would describe Bond’s feud-driven act of
spreading irritating chemicals on Haynes’s door knob and
mailbox as ‘combat.’ ” Ante, at 15–16. Undoubtedly so, but
undoubtedly beside the point, since the Act supplies its
own definition of “chemical weapon,” which unquestiona-
bly does bring Bond’s action within the statutory prohibi-
tion. The Court retorts that “it is not unusual to consider
the ordinary meaning of a defined term, particularly when
there is dissonance between that ordinary meaning and
the reach of the definition.” Ante, at 16. So close to true!
What is “not unusual” is using the ordinary meaning of
the term being defined for the purpose of resolving an
ambiguity in the definition. When, for example, “draft,” a
word of many meanings, is one of the words used in a
definition of “breeze,” we know it has nothing to do with
military conscription or beer. The point is illustrated by
the almost-relevant case the Court cites for its novel prin-
ciple, Johnson v. United States, 559 U. S. 133 (2010).
There the defined term was “violent felony,” which the Act
defined as an offense that “ ‘has as an element the use . . .
of physical force against the person of another.’ ” Id., at
135 (quoting §924(e)(2)(B)(i)). We had to figure out what
“physical force” meant, since the statute “d[id] not define”
it. Id., at 138 (emphasis added). So we consulted (among
other things) the general meaning of the term being de-
fined, “violent felony.” Id., at 140.
   In this case, by contrast, the ordinary meaning of the
term being defined is irrelevant, because the statute’s own
6                  BOND v. UNITED STATES

                SCALIA, J., concurring in judgment

definition—however expansive—is utterly clear: any
“chemical which through its chemical action on life proc-
esses can cause death, temporary incapacitation or per-
manent harm to humans or animals,” §229F(8)(A), unless
the chemical is possessed or used for a “peaceful purpose,”
§229F(1)(A), (7)(A). The statute parses itself. There is no
opinion of ours, and none written by any court or put
forward by any commentator since Aristotle, which says,
or even suggests, that “dissonance” between ordinary
meaning and the unambiguous words of a definition is to
be resolved in favor of ordinary meaning. If that were the
case, there would hardly be any use in providing a defini-
tion. No, the true rule is entirely clear: “When a statute
includes an explicit definition, we must follow that defini-
tion, even if it varies from that term’s ordinary meaning.”
Stenberg v. Carhart, 530 U. S. 914, 942 (2000) (emphasis
added). Once again, contemplate the judge-empowering
consequences of the new interpretive rule the Court today
announces: When there is “dissonance” between the statu-
tory definition and the ordinary meaning of the defined
word, the latter may prevail.
   But even text clear on its face, the Court suggests, must
be read against the backdrop of established interpretive
presumptions. Thus, we presume “that a criminal statute
derived from the common law carries with it the require-
ment of a culpable mental state—even if no such limita-
tion appears in the text.” Ante, at 11. And we presume
that “federal statutes do not apply outside the United
States.” Ibid. Both of those are, indeed, established in-
terpretive presumptions that are (1) based upon realistic
assessments of congressional intent, and (2) well known to
Congress—thus furthering rather than subverting genu-
ine legislative intent. To apply these presumptions, then,
is not to rewrite clear text; it is to interpret words fairly, in
light of their statutory context. But there is nothing ei-
ther (1) realistic or (2) well known about the presumption
                 Cite as: 572 U. S. ____ (2014)            7

               SCALIA, J., concurring in judgment

the Court shoves down the throat of a resisting statute
today. Who in the world would have thought that a defini-
tion is inoperative if it contradicts ordinary meaning?
When this statute was enacted, there was not yet a “Bond
presumption” to that effect—though presumably Congress
will have to take account of the Bond presumption in the
future, perhaps by adding at the end of all its definitions
that depart from ordinary connotation “and we really
mean it.”
           C. The Statute as Judicially Amended
  I suspect the Act will not survive today’s gruesome
surgery. A criminal statute must clearly define the con-
duct it proscribes. If it does not “ ‘give a person of ordi-
nary intelligence fair notice’ ” of its scope, United States
v. Batchelder, 442 U. S. 114, 123 (1979), it denies due
process.
  The new §229(a)(1) fails that test. Henceforward, a
person “shall be fined . . . , imprisoned for any term of
years, or both,” §229A(a)(1)—or, if he kills someone, “shall
be punished by death or imprisoned for life,” §229A(a)(2)—
whenever he “develop[s], produce[s], otherwise acquire[s],
transfer[s] directly or indirectly, receive[s], stockpile[s],
retain[s], own[s], possess[es], or use[s], or threaten[s] to
use,” §229(a)(1), any chemical “of the sort that an ordinary
person would associate with instruments of chemical war­
fare,” ante, at 15 (emphasis added). Whether that test is
satisfied, the Court unhelpfully (and also illogically) ex-
plains, depends not only on the “particular chemicals that
the defendant used” but also on “the circumstances in
which she used them.” Ibid. The “detergent under the
kitchen sink” and “the stain remover in the laundry room”
are apparently out, ante, at 16—but what if they are
deployed to poison a neighborhood water fountain? Poi-
soning a goldfish tank is also apparently out, ante, at 17,
but what if the fish belongs to a Congressman or Governor
8                     BOND v. UNITED STATES

                   SCALIA, J., concurring in judgment

and the act is meant as a menacing message, a small-time
equivalent of leaving a severed horse head in the bed? See
ibid. (using the “concerns” driving the Convention—“acts
of war, assassination, and terrorism”—as guideposts of
statutory meaning). Moreover, the Court’s illogical embel-
lishment seems to apply only to the “use” of a chemical,
ante, at 15, but “use” is only 1 of 11 kinds of activity that
the statute prohibits. What, one wonders, makes some-
thing a “chemical weapon” when it is merely “stockpile[d]”
or “possess[ed]?” To these questions and countless others,
one guess is as bad as another.
   No one should have to ponder the totality of the circum-
stances in order to determine whether his conduct is a
felony. Yet that is what the Court will now require of all
future handlers of harmful toxins—that is to say, all of us.
Thanks to the Court’s revisions, the Act, which before was
merely broad, is now broad and unintelligible. “[N]o
standard of conduct is specified at all.” Coates v. Cincin­
nati, 402 U. S. 611, 614 (1971). Before long, I suspect,
courts will be required to say so.
               II. The Constitutional Question
  Since the Act is clear, the real question this case pre-
sents is whether the Act is constitutional as applied to
petitioner. An unreasoned and citation-less sentence from
our opinion in Missouri v. Holland, 252 U. S. 416 (1920),
purported to furnish the answer: “If the treaty is valid”—
and no one argues that the Convention is not—“there can
be no dispute about the validity of the statute under Arti-
cle I, §8, as a necessary and proper means to execute the
powers of the Government.” Id., at 432.4 Petitioner and
——————
  4 Nineteen years earlier, the Court embraced a similar view—also

without reasoning. See Neely v. Henkel, 180 U. S. 109, 121 (1901) (“The
power of Congress to make all laws necessary and proper for carrying
into execution . . . all [powers] vested in the Government of the United
States . . . includes the power to enact such legislation as is appropriate
                      Cite as: 572 U. S. ____ (2014)                     9

                   SCALIA, J., concurring in judgment

her amici press us to consider whether there is anything
to this ipse dixit. The Constitution’s text and structure
show that there is not.5
                           A. Text
  Under Article I, §8, cl. 18, Congress has the power “[t]o
make all Laws which shall be necessary and proper for
carrying into Execution the foregoing Powers and all other
Powers vested by this Constitution in the Government
of the United States, or in any Department or Officer
thereof.” One such “other Powe[r]” appears in Article II,
§2, cl. 2: “[The President] shall have Power, by and with
the Advice and Consent of the Senate, to make Treaties,
provided two thirds of the Senators present concur.” Read
together, the two Clauses empower Congress to pass laws
“necessary and proper for carrying into Execution . . . [the]
Power . . . to make Treaties.”
  It is obvious what the Clauses, read together, do not say.
They do not authorize Congress to enact laws for carrying
into execution “Treaties,” even treaties that do not execute
themselves, such as the Chemical Weapons Convention.6
——————
to give efficacy to any stipulations which it is competent for the Presi-
dent by and with the advice and consent of the Senate to insert in a
treaty with a foreign power”). There is also dictum arguably favorable
to Holland in Prigg v. Pennsylvania, 16 Pet. 539, 619 (1842) (“[T]he
power is nowhere in positive terms conferred upon Congress to make
laws to carry the stipulations of treaties into effect. It has been sup-
posed to result from the duty of the national government to fulfill all
the obligations of treaties”). But see Mayor of New Orleans v. United
States, 10 Pet. 662, 736 (1836) (“The government of the United States
. . . is one of limited powers. It can exercise authority over no subjects,
except those which have been delegated to it. Congress cannot, by
legislation, enlarge the federal jurisdiction, nor can it be enlarged
under the treaty-making power”).
    5 I agree with the Court that the Government waived its defense of

the Act as an exercise of the commerce power. Ante, at 8–9.
    6 Non-self-executing treaties are treaties whose commitments do not

“automatically have effect as domestic law,” Medellín v. Texas, 552
10                   BOND v. UNITED STATES

                  SCALIA, J., concurring in judgment

Surely it makes sense, the Government contends, that
Congress would have the power to carry out the obliga-
tions to which the President and the Senate have commit-
ted the Nation. The power to “carry into Execution” the
“Power . . . to make Treaties,” it insists, has to mean the
power to execute the treaties themselves.
   That argument, which makes no pretense of resting on
text, unsurprisingly misconstrues it. Start with the
phrase “to make Treaties.” A treaty is a contract with a
foreign nation made, the Constitution states, by the Presi-
dent with the concurrence of “two thirds of the Senators
present.” That is true of self-executing and non-self-
executing treaties alike; the Constitution does not distin-
guish between the two. So, because the President and the
Senate can enter into a non-self-executing compact with a
foreign nation but can never by themselves (without the
House) give that compact domestic effect through legisla-
tion, the power of the President and the Senate “to make”
a Treaty cannot possibly mean to “enter into a compact
with a foreign nation and then give that compact domestic
legal effect.” We have said in another context that a right
“to make contracts” (a treaty, of course, is a contract) does
not “extend . . . to conduct . . . after the contract relation
has been established . . . . Such postformation conduct
does not involve the right to make a contract, but rather
implicates the performance of established contract obliga-
tions.” Patterson v. McLean Credit Union, 491 U. S. 164,
177 (1989) (emphasis added).           Upon the President’s
agreement and the Senate’s ratification, a treaty—no
matter what kind—has been made and is not susceptible
of any more making.
   How might Congress have helped “carr[y]” the power to
——————
U. S. 491, 504 (2008), and “can only be enforced pursuant to legislation
to carry them into effect,” Whitney v. Robertson, 124 U. S. 190, 194
(1888).
                  Cite as: 572 U. S. ____ (2014)            11

                SCALIA, J., concurring in judgment

make the treaty—here, the Chemical Weapons Conven-
tion—“into Execution”? In any number of ways. It could
have appropriated money for hiring treaty negotiators,
empowered the Department of State to appoint those
negotiators, formed a commission to study the benefits
and risks of entering into the agreement, or paid for a
bevy of spies to monitor the treaty-related deliberations of
other potential signatories. See G. Lawson & G. Seidman,
The Constitution of Empire: Territorial Expansion and
American Legal History 63 (2004). The Necessary and
Proper Clause interacts similarly with other Article II
powers: “[W]ith respect to the executive branch, the
Clause would allow Congress to institute an agency to
help the President wisely employ his pardoning power
. . . . Most important, the Clause allows Congress to estab-
lish officers to assist the President in exercising his ‘execu-
tive Power.’ ” Calabresi & Prakash, The President’s Power
to Execute the Laws, 104 Yale L. J. 541, 591 (1994).
    But a power to help the President make treaties is not a
power to implement treaties already made. See generally
Rosenkranz, Executing the Treaty Power, 118 Harv.
L. Rev. 1867 (2005). Once a treaty has been made, Con-
gress’s power to do what is “necessary and proper” to
assist the making of treaties drops out of the picture. To
legislate compliance with the United States’ treaty obliga-
tions, Congress must rely upon its independent (though
quite robust) Article I, §8, powers.
                       B. Structure
  “[T]he Constitutio[n] confer[s] upon Congress . . . not all
governmental powers, but only discrete, enumerated
ones.” Printz v. United States, 521 U. S. 898, 919 (1997).
And, of course, “enumeration presupposes something not
enumerated.” Gibbons v. Ogden, 9 Wheat. 1, 195 (1824).
  But in Holland, the proponents of unlimited congres-
sional power found a loophole: “By negotiating a treaty
12                 BOND v. UNITED STATES

                SCALIA, J., concurring in judgment

and obtaining the requisite consent of the Senate, the
President . . . may endow Congress with a source of legis-
lative authority independent of the powers enumerated in
Article I.” L. Tribe, American Constitutional Law §4–4,
pp. 645–646 (3d ed. 2000). Though Holland’s change to
the Constitution’s text appears minor (the power to carry
into execution the power to make treaties becomes the
power to carry into execution treaties), the change to its
structure is seismic.
   To see why vast expansion of congressional power is not
just a remote possibility, consider two features of the
modern practice of treaty making. In our Nation’s early
history, and extending through the time when Holland
was written, treaties were typically bilateral, and ad-
dressed only a small range of topics relating to the obli-
gations of each state to the other, and to citizens of the
other—military neutrality, for example, or military alliance,
or guarantee of most-favored-nation trade treatment. See
Bradley, The Treaty Power and American Federalism, 97
Mich. L. Rev. 390, 396 (1998). But beginning in the last
half of the last century, many treaties were “detailed
multilateral instruments negotiated and drafted at inter-
national conferences,” ibid., and they sought to regulate
states’ treatment of their own citizens, or even “the activi-
ties of individuals and private entities,” A. Chayes & A.
Chayes, The New Sovereignty: Compliance with Interna-
tional Regulatory Agreements 14 (1995). “[O]ften vague
and open-ended,” such treaties “touch on almost every
aspect of domestic civil, political, and cultural life.” Brad-
ley & Goldsmith, Treaties, Human Rights, and Condi-
tional Consent, 149 U. Pa. L. Rev. 399, 400 (2000).
   Consider also that, at least according to some scholars,
the Treaty Clause comes with no implied subject-matter
limitations. See, e.g., L. Henkin, Foreign Affairs and the
United States Constitution 191, 197 (2d ed. 1996); but see
Bradley, supra, at 433–439. On this view, “[t]he Tenth
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                SCALIA, J., concurring in judgment

Amendment . . . does not limit the power to make treaties
or other agreements,” Restatement (Third) of Foreign
Relations Law of the United States §302, Comment d, p.
154 (1986), and the treaty power can be used to regulate
matters of strictly domestic concern, see id., at Comment
c, p. 153; but see post, at 3–16 (THOMAS, J., concurring in
judgment).
   If that is true, then the possibilities of what the Federal
Government may accomplish, with the right treaty in
hand, are endless and hardly farfetched. It could begin, as
some scholars have suggested, with abrogation of this
Court’s constitutional rulings. For example, the holding
that a statute prohibiting the carrying of firearms near
schools went beyond Congress’s enumerated powers,
United States v. Lopez, 514 U. S. 549, 551 (1995), could be
reversed by negotiating a treaty with Latvia providing
that neither sovereign would permit the carrying of guns
near schools. Similarly, Congress could reenact the inval-
idated part of the Violence Against Women Act of 1994
that provided a civil remedy for victims of gender-
motivated violence, just so long as there were a treaty on
point—and some authors think there already is, see
MacKinnon, The Supreme Court, 1999 Term, Comment,
114 Harv. L. Rev. 135, 167 (2000).
   But reversing some of this Court’s decisions is the least
of the problem. Imagine the United States’ entry into an
Antipolygamy Convention, which called for—and Congress
enacted—legislation providing that, when a spouse of a
man with more than one wife dies intestate, the surviv-
ing husband may inherit no part of the estate. Constitu-
tional? The Federalist answers with a rhetorical ques-
tion: “Suppose by some forced constructions of its authority
(which indeed cannot easily be imagined) the Federal
Legislature should attempt to vary the law of descent in
any State; would it not be evident that . . . it had exceeded
its jurisdiction and infringed upon that of the State?” The
14                BOND v. UNITED STATES

               SCALIA, J., concurring in judgment

Federalist No. 33, at 206 (A. Hamilton). Yet given the
Antipolygamy Convention, Holland would uphold it. Or
imagine that, to execute a treaty, Congress enacted a
statute prohibiting state inheritance taxes on real prop-
erty. Constitutional? Of course not. Again, The Federalist:
“Suppose . . . [Congress] should undertake to abrogate a
land tax imposed by the authority of a State, would it not
be equally evident that this was an invasion of that con-
current jurisdiction in respect to this species of tax which
its constitution plainly supposes to exist in the State
governments?” No. 33, at 206. Holland would uphold it.
As these examples show, Holland places Congress only
one treaty away from acquiring a general police power.
   The Necessary and Proper Clause cannot bear such
weight. As Chief Justice Marshall said regarding it, no
“great substantive and independent power” can be “im-
plied as incidental to other powers, or used as a means of
executing them.” McCulloch v. Maryland, 4 Wheat. 316,
411 (1819); see Baude, Rethinking the Federal Eminent
Domain Power, 122 Yale L. J. 1738, 1749–1755 (2013).
No law that flattens the principle of state sovereignty,
whether or not “necessary,” can be said to be “proper.” As
an old, well-known treatise put it, “it would not be a proper
or constitutional exercise of the treaty-making power to
provide that Congress should have a general legislative
authority over a subject which has not been given it by the
Constitution.” 1 W. Willoughby, The Constitutional Law
of the United States §216, p. 504 (1910).
   We would not give the Government’s support of the
Holland principle the time of day were we confronted with
“treaty-implementing” legislation that abrogated the
freedom of speech or some other constitutionally protected
individual right. We proved just that in Reid v. Covert,
354 U. S. 1 (1957), which held that commitments made in
treaties with Great Britain and Japan would not permit
civilian wives of American servicemen stationed in those
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                SCALIA, J., concurring in judgment

countries to be tried for murder by court-martial. The
plurality opinion said that “no agreement with a foreign
nation can confer power on the Congress, or on any other
branch of Government, which is free from the restraints of
the Constitution.” Id., at 16.
   To be sure, the Reid plurality purported to distinguish
the ipse dixit of Holland with its own unsupported ipse
dixit. “[T]he people and the States,” it said, “have delegated
[the treaty] power to the National Government [so] the
Tenth Amendment is no barrier.” 354 U. S., at 18. The
opinion does not say why (and there is no reason why) only
the Tenth Amendment, and not the other nine, has been
“delegated” away by the treaty power. The distinction
between provisions protecting individual liberty, on the
one hand, and “structural” provisions, on the other, cannot
be the explanation, since structure in general—and espe-
cially the structure of limited federal powers—is designed
to protect individual liberty. “The federal structure . . .
secures the freedom of the individual. . . . By denying any
one government complete jurisdiction over all the concerns
of public life, federalism protects the liberty of the individ-
ual from arbitrary power.” Bond v. United States, 564
U. S. ___, ___ (2011) (slip op., at 9–10).
   The Government raises a functionalist objection: If the
Constitution does not limit a self-executing treaty to the
subject matter delineated in Article I, §8, then it makes no
sense to impose that limitation upon a statute implement-
ing a non-self-executing treaty. See Tr. of Oral Arg. 32–33.
The premise of the objection (that the power to make self-
executing treaties is limitless) is, to say the least, argua-
ble. But even if it is correct, refusing to extend that prop-
osition to non-self-executing treaties makes a great deal of
sense. Suppose, for example, that the self-aggrandizing
Federal Government wishes to take over the law of intes-
tacy. If the President and the Senate find in some foreign
state a ready accomplice, they have two options. First,
16                 BOND v. UNITED STATES

                SCALIA, J., concurring in judgment

they can enter into a treaty with “stipulations” specific
enough that they “require no legislation to make them
operative,” Whitney v. Robertson, 124 U. S. 190, 194
(1888), which would mean in this example something like
a comprehensive probate code. But for that to succeed, the
President and a supermajority of the Senate would need to
reach agreement on all the details—which, when once
embodied in the treaty, could not be altered or superseded
by ordinary legislation. The second option—far the better
one—is for Congress to gain lasting and flexible control
over the law of intestacy by means of a non-self-executing
treaty. “[Implementing] legislation is as much subject to
modification and repeal by Congress as legislation upon
any other subject.” Ibid. And to make such a treaty, the
President and Senate would need to agree only that they
desire power over the law of intestacy.
  The famous scholar and jurist Henry St. George Tucker
saw clearly the danger of Holland’s ipse dixit five years
before it was written:
     “[The statement is made that] if the treaty-making
     power, composed of the President and Senate, in dis-
     charging its functions under the government, finds
     that it needs certain legislative powers which Con-
     gress does not possess to carry out its desires, it may
     . . . infuse into Congress such powers, although the
     Framers of the Constitution omitted to grant them to
     Congress. . . . Every reputable commentator upon the
     Constitution from Story down to the present day, has
     held that the legislative powers of Congress lie in
     grant and are limited by such grant. . . . [S]hould such
     a construction as that asserted in the above statement
     obtain through judicial endorsement, our system of
     government would soon topple and fall.” Limitations
     on the Treaty-Making Power Under the Constitution
     of the United States §113, pp. 129–130 (1915).
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                SCALIA, J., concurring in judgment

                         *     *    *
   We have here a supposedly “narrow” opinion which, in
order to be “narrow,” sets forth interpretive principles
never before imagined that will bedevil our jurisprudence
(and proliferate litigation) for years to come. The immedi-
ate product of these interpretive novelties is a statute that
should be the envy of every lawmaker bent on trapping
the unwary with vague and uncertain criminal prohibi-
tions. All this to leave in place an ill-considered ipse dixit
that enables the fundamental constitutional principle of
limited federal powers to be set aside by the President and
Senate’s exercise of the treaty power. We should not have
shirked our duty and distorted the law to preserve that
assertion; we should have welcomed and eagerly grasped
the opportunity—nay, the obligation—to consider and
repudiate it.
                  Cite as: 572 U. S. ____ (2014)            1

               THOMAS, J., concurring in judgment

SUPREME COURT OF THE UNITED STATES
                          _________________

                           No. 12–158
                          _________________


    CAROL ANNE BOND, PETITIONER v. UNITED

                  STATES 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE THIRD CIRCUIT

                         [June 2, 2014]


   JUSTICE THOMAS, with whom JUSTICE SCALIA joins, and
with whom JUSTICE ALITO joins as to Parts I, II, and III,
concurring in the judgment.
   By its clear terms, the statute at issue in this case regu-
lates local criminal conduct that is subject to the powers
reserved to the States. See ante, at 1–2 (SCALIA, J., con-
curring in judgment). That aggrandizement of federal
power cannot be justified as a “necessary and proper”
means of implementing a treaty addressing similar subject
matter. See ante, at 8–9. To the contrary, reading the
Necessary and Proper Clause to expand Congress’ power
upon the ratification of every new treaty defies an indis-
putable first principle of our constitutional order: “ ‘[T]he
Constitution created a Federal Government of limited
powers.’ ” New York v. United States, 505 U. S. 144, 155
(1992) (quoting Gregory v. Ashcroft, 501 U. S. 452, 457
(1991)). I accordingly join JUSTICE SCALIA’s opinion in
full.
   I write separately to suggest that the Treaty Power is
itself a limited federal power. Cf. United States v. Lopez,
514 U. S. 549, 584 (1995) (THOMAS, J., concurring) (“[W]e
always have rejected readings of . . . the scope of federal
power that would permit Congress to exercise a police
power”). The Constitution empowers the President, “by
and with the Advice and Consent of the Senate, to make
2                 BOND v. UNITED STATES

               THOMAS, J., concurring in judgment

Treaties, provided two thirds of the Senators present
concur.” Art. II, §2. The Constitution does not, however,
comprehensively define the proper bounds of the Treaty
Power, and this Court has not yet had occasion to do so.
As a result, some have suggested that the Treaty Power is
boundless—that it can reach any subject matter, even
those that are of strictly domestic concern. See, e.g., Re-
statement (Third) of Foreign Relations Law of the United
States, §302, Comment c (1986). A number of recent
treaties reflect that suggestion by regulating what appear
to be purely domestic affairs. See, e.g., Bradley, The Treaty
Power and American Federalism, 97 Mich. L. Rev. 390,
402–409 (1998) (hereinafter Bradley) (citing examples).
  Yet to interpret the Treaty Power as extending to every
conceivable domestic subject matter—even matters with-
out any nexus to foreign relations—would destroy the
basic constitutional distinction between domestic and
foreign powers. See United States v. Curtiss-Wright Ex-
port Corp., 299 U. S. 304, 319 (1936) (“[T]he federal power
over external affairs [is] in origin and essential character
different from that over internal affairs . . .”). It would
also lodge in the Federal Government the potential for “a
‘police power’ over all aspects of American life.” Lopez,
supra, at 584 (THOMAS, J., concurring). A treaty-based
power of that magnitude—no less than a plenary power of
legislation—would threaten “ ‘ “the liberties that derive
from the diffusion of sovereign power.” ’ ” Bond v. United
States, 564 U. S. ___, ___ (2011) (slip op., at 9). And a
treaty-based police power would pose an even greater
threat when exercised through a self-executing treaty
because it would circumvent the role of the House of Rep-
resentatives in the legislative process. See The Federalist
No. 52, p. 355 (J. Cooke ed. 1961) (J. Madison) (noting that
the House has a more “immediate dependence on, & an
intimate sympathy with the people”).
  I doubt the Treaty Power creates such a gaping loophole
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               THOMAS, J., concurring in judgment

in our constitutional structure. Although the parties have
not challenged the constitutionality of the particular
treaty at issue here, in an appropriate case I believe the
Court should address the scope of the Treaty Power as it
was originally understood. Today, it is enough to high-
light some of the structural and historical evidence sug-
gesting that the Treaty Power can be used to arrange
intercourse with other nations, but not to regulate purely
domestic affairs.
                              I
   The Treaty Power was not drafted on a blank slate. To
the contrary, centuries of experience—reflected in treatises,
dictionaries, and actual practice—shaped the contours of
that power.
   Early treatises discussed a wide variety of treaties that
nevertheless shared a common thread: All of them gov-
erned genuinely international matters such as war, peace,
and trade between nations. See, e.g., 2 H. Grotius, De
Jure Belli Ac Pacis 394–396 (1646 ed., F. Kelsey transl.
1925) (treaties are made “for the sake either of peace or of
some alliance,” including “for the restoration of captives
and of captured property, and for safety”; “that neither
signatory shall have fortresses in the territory of the
other, or defend the subjects of the other, or furnish a
passage to the enemy of the other”; and for “commercial
relations” and agreements on “import duties” (footnote
omitted)); 2 S. Pufendorf, De Jure Naturae et Gentium
1331 (1688 ed., C. Oldfather & W. Oldfather transls. 1934)
(treaties are made “to form some union or society, the end
of which is either commercial relations, or a united front
in war”); 3 E. Vattel, The Law of Nations 165 (1758 ed., C.
Fenwick transl. 1916) (treaties, which “can be subdivided
into as many classes as there are varieties in the character
of national relations,” “deal with conditions of commerce,
with mutual defense, with belligerent relations, with
4                 BOND v. UNITED STATES

               THOMAS, J., concurring in judgment

rights of passage, . . . stipulations not to fortify certain
places, etc.”).
   Founding-era dictionaries reflect a similar understand-
ing. To be sure, some early dictionaries briefly defined
“treaty” simply as a “compact of accommodation relating to
public affairs.” See, e.g., 2 S. Johnson, A Dictionary of the
English Language 2056 (rev. 4th ed. 1773). More detailed
definitions, however, recognized the particular character
of treaties as addressing matters of intercourse between
nations rather than domestic regulation. See, e.g., J.
Buchanan, A New English Dictionary (1769) (defining
“treaty” as “[a] covenant or agreement between several
nations for peace, commerce, navigation, &c.”); N. Bailey,
An Universal Etymological English Dictionary (26th ed.
1789) (same); J. Montefiore, A Commercial Dictionary
(1803) (noting “treaties of alliance” for military aid; “trea-
ties of subsidy” for the provision of soldiers; treaties of
navigation and commerce; treaties governing fishing and
timber rights; and treaties on import duties); 2 N. Web-
ster, An American Dictionary of the English Language 97
(1828) (noting “treaties for regulating commercial inter-
course, treaties of alliance, offensive and defensive, trea-
ties for hiring troops, [and] treaties of peace”).
   Treaty practice under the Articles of Confederation was
also consistent with the understanding that treaties gov-
ern matters of international intercourse. The Articles
provided: “The United States in Congress assembled, shall
have the sole and exclusive right and power of . . . entering
into treaties and alliances . . . .” Art. IX. The Congress of
the Confederation exercised that power by making treaties
that fell squarely within the traditional scope of the power.
See, e.g., Treaty with the Cherokee, Art. IV, Nov. 28,
1785, 7 Stat. 19, 2 C. Kappler, Indian Affairs: Laws and
Treaties 9 (1904) (territorial borders); Definitive Treaty of
Peace, U. S.-Gr. Brit., Art. VII, Sept. 3, 1783, 8 Stat. 83,
T. S. No. 104 (peace); Contract for the Payment of Loans,
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               THOMAS, J., concurring in judgment

U. S.-Fr., Arts. I–IV, July 16, 1782, 8 Stat. 614–615, T. S.
No. 831⁄4 (repayment of sovereign debt); Definitive Treaty
of Peace, U. S.-Gr. Brit., Art. III, Sept. 3, 1783, 8 Stat. 82,
T. S. No. 104 (fishery rights in disputed waters); Treaty of
Amity and Commerce, U. S.-Prussia, Arts. IV–IX, Sept.
10, 1785, 8 Stat. 86–88, T. S. No. 292 (treatment of vessels
in a treaty partners’ waters); Convention Defining and
Establishing the Functions and Privileges of Consuls and
Vice-Consuls, U. S.-Fr., Arts. I–III, Nov. 14, 1788, 8 Stat.
106–108, T. S. No. 84 (privileges and immunities of diplo-
matic officials); Treaty of Amity and Commerce, U. S.-
Swed., Arts. III–IV, Apr. 3, 1783, 8 Stat. 60, T. S. No. 346
(rights of citizens of one treaty partner residing in the
territory of the other).
   These treaties entered into under the Articles of Con-
federation would not have suggested to the Framers that
granting a power to “make Treaties” included authoriza-
tion to regulate purely domestic matters. Whenever these
treaties affected legal rights within United States territory,
they addressed only rights that related to foreign sub-
jects or foreign property. See, e.g., Treaty of Amity and
Commerce, U. S.-Neth., Art. IV, Oct. 8, 1782, 8 Stat. 34
(affording burial rights “when any subjects or inhabitants
of either party shall die in the territory of the other”);
Treaty with the Cherokee, Art. VII, 7 Stat. 19, 2 Kappler,
supra, at 10 (“If any citizen of the United States . . . shall
commit a robbery or murder, or other capital crime, on any
Indian, such offender or offenders shall be punished in the
same manner as if [the crime] had been committed on a
citizen of the United States . . .”); Convention Relative to
Recaptured Vessels, U. S.-Neth., Oct. 8, 1782, 8 Stat. 50,
T. S. No. 250 (“The vessells of either of the two nations re-
captured by the privateers of the other, shall be restored
to the first proprietor . . .”). Preconstitutional practice
therefore reflects the use of the treaty-making power only
for matters of international intercourse; that practice
6                 BOND v. UNITED STATES

              THOMAS, J., concurring in judgment

provides no support for using treaties to regulate purely
domestic affairs.
                              II

                              A

   Debates preceding the ratification of the proposed Con-
stitution confirm the limited scope of the powers possessed
by the Federal Government generally; the Treaty Power
was no exception. The Framers understood that most
regulatory matters were to be left to the States. See The
Federalist No. 45, at 313 (J. Madison) (“The powers dele-
gated by the proposed Constitution to the Federal Gov-
ernment, are few and defined”); see also Lopez, 514 U. S.,
at 590–592 (THOMAS, J., concurring) (citing sources).
Consistent with that general understanding of limited
federal power, evidence from the ratification campaign
suggests that the Treaty Power was limited and, in par-
ticular, confined to matters of intercourse with other
nations.
   In essays during the ratification campaign in New York,
James Madison took the view that the Treaty Power was
inherently limited. The Federal Government’s powers,
Madison wrote, “will be exercised principally on external
objects, as war, peace, negotiation, and foreign com-
merce”—the traditional subjects of treaty-making. The
Federalist No. 45, at 313. If the “external” Treaty Power
contained a capacious domestic regulatory authority, that
would plainly conflict with Madison’s firm understanding
that “[t]he powers delegated by the proposed Constitution
to the Federal Government, are few and defined.” Ibid.
Madison evidently saw no conflict, however, because the
Treaty Power included authority to “regulate the inter-
course with foreign nations” rather than all domestic
affairs. Id., No. 42, at 279.
   Madison reiterated that understanding at the 1788
Virginia ratifying convention, where the most extensive
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               THOMAS, J., concurring in judgment

discussion of the proposed Treaty Power occurred, see
Bradley 410; Golove, Treaty-Making and the Nation, 98
Mich. L. Rev. 1075, 1141–1142 (2000) (hereinafter Golove).
There, Anti-Federalists leveled the charge that the Treaty
Power gave the Federal Government excessive power.
See, e.g., 3 Debates on the Federal Constitution 509 (J.
Elliot 2d ed. 1876) (hereinafter Elliot’s Debates) (G. Ma-
son) (“The President and Senate can make any treaty
whatsoever”); id., at 513 (P. Henry) (“To me this power
appears still destructive; for they can make any treaty”).
But Madison insisted that just “because this power is
given to Congress,” it did not follow that the Treaty Power
was “absolute and unlimited.” Id., at 514. The President
and the Senate lacked the power “to dismember the em-
pire,” for example, because “[t]he exercise of the power
must be consistent with the object of the delegation.” Ibid.
“The object of treaties,” in Madison’s oft-repeated formula-
tion, “is the regulation of intercourse with foreign nations,
and is external.” Ibid.
   Although Alexander Hamilton undoubtedly believed
that the Treaty Power was broad within its proper sphere,
see infra, at 8, the view he expressed in essays during the
New York ratification campaign is entirely consistent with
Madison’s. After noting that the Treaty Power was one of
the “most unexceptionable parts” of the proposed Consti-
tution, Hamilton distinguished the Treaty Power from the
legislative power “to prescribe rules for the regulation of
the society” and from the executive power to “execut[e] . . .
the laws.” The Federalist No. 75, at 503–504. “The power
of making treaties,” he concluded, “is plainly neither the
one nor the other.” Id., at 504. Rather, Hamilton ex-
plained that treaties “are not rules prescribed by the
sovereign to the subject, but agreements between sover-
eign and sovereign.” Id., at 504–505. That description is
difficult to square with a view of the Treaty Power that
would allow the Federal Government to prescribe rules
8                  BOND v. UNITED STATES

                THOMAS, J., concurring in judgment

over all aspects of domestic life.
                              B
   It did not escape the attention of the Framers that the
Treaty Power was drafted without explicitly enumerated
limits on what sorts of treaties are permissible. See, e.g.,
Hamilton, The Defence No. XXXVI, in 20 Papers of Alex-
ander Hamilton 6 (H. Syrett ed. 1974) (“A power ‘to make
treaties,’ granted in these indefinite terms, extends to all
kinds of treaties and with all the latitude which such a
power under any form of Government can possess”). The
Articles of Confederation had, for example, explicitly
restricted certain categories of treaties.      See Art. IX
(“[N]o treaty of commerce shall be made whereby the legis-
lative power of the respective States shall be restrained
from imposing such imposts and duties on foreigners, as
their own people are subjected to, or from prohibiting the
exportation or importation of any species of goods or com-
modities whatsoever”). The Constitution omitted those
restrictions.
   That decision was not a grant of unlimited power, but
rather a grant of flexibility; the Federal Government
needed the ability to respond to unforeseeable varieties of
intercourse with other nations. James Madison, for ex-
ample, did “not think it possible to enumerate all the cases
in which such external regulations would be necessary.” 3
Elliot’s Debates 514; see also id., at 363 (E. Randolph)
(“The various contingencies which may form the object of
treaties, are, in the nature of things, incapable of defini-
tion”). But Madison nevertheless recognized that any
exercise of the Treaty Power “must be consistent with the
object of the delegation,” which is “the regulation of inter-
course with foreign nations.” Id., at 514; see also Hamil-
ton, The Defence, supra, at 6 (“[W]hatever is a proper
subject of compact between Nation & Nation may be em-
braced by a Treaty” (emphasis added)). That understand-
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               THOMAS, J., concurring in judgment

ing of the Treaty Power did not permit the President and
the Senate to exercise domestic authority commensurate
with their substantial power over external affairs.
                              C
   The understanding that treaties are limited to, in Madi-
son’s words, “the regulation of intercourse with foreign
nations,” endured in the years after the Constitution was
ratified.
   In 1796, an extended debate regarding the proper scope
of the Treaty Power arose in the aftermath of a controver-
sial treaty with Great Britain that addressed the validity
of prerevolutionary debts and the property rights of Brit-
ish subjects. Treaty of Amity, Commerce and Navigation,
Nov. 19, 1794, 8 Stat. 116, T. S. No. 105. When President
Washington requested appropriations to implement that
so-called “Jay Treaty” (after its chief negotiator, John Jay),
the House of Representatives engaged in a month-long
floor debate over its own role in the process of implement-
ing treaties. See 5 Annals of Cong. 426 (1796); see gener-
ally D. Currie, The Constitution in Congress: The Fed-
eralist Period 1789–1801, pp. 211–217 (1997). Some
Congressmen argued that the House had a right to inde-
pendently review the merits of the treaty. See, e.g., 5
Annals of Cong. 427–428 (remarks of Rep. Livingston)
(“[T]he House w[as] vested with a discretionary power of
carrying the Treaty into effect, or refusing it their sanc-
tion”). Others insisted that “if the Treaty was the su-
preme law of the land, then there was no discretionary
power in the House, except on the question of its constitu-
tionality.” Id., at 436–437 (Rep. Murray).
   That latter group relied in part on the observation that
the Treaty Power was limited by its nature, and thus the
Constitution’s failure to specify a role for the House did
not pose a mortal threat to that Chamber’s legislative
prerogatives. Representative James Hillhouse of Connect-
10                 BOND v. UNITED STATES

                THOMAS, J., concurring in judgment

icut expounded that position in the floor debate. Hillhouse
recognized that the House had an “indispensable duty to
look into every Treaty” to ensure that it is constitutional,
i.e., “whether it related to objects within the province of
the Treaty-making power, a power which is not unlim-
ited.” Id., at 660. He further explained that “[t]he objects
upon which it can operate are understood and well de-
fined, and if the Treaty-making power were to embrace
other objects, their doings would have no more binding
force than if the Legislature were to assume and exercise
judicial powers under the name of legislation.” Ibid.
   Hillhouse “advert[ed] to the general definition of the
Treaty-making power” to explain why the Treaty Power
was not a threat to the House’s legislative prerogatives:
     “[I]f we look into our code of laws, we shall find few of
     them that can be affected, to any great degree, by the
     Treaty-making power. All laws regulating our own
     internal police, so far as the citizens of the United
     States alone are concerned, are wholly beyond its
     reach; no foreign nation having any interest or con-
     cern in that business, every attempt to interfere
     would be a mere nullity, as much as if two individuals
     were to enter into a contract to regulate the conduct
     or actions of a third person, who was no party to such
     contract.” Id., at 662.
He accordingly denied that “the President and Senate
hav[e] it in their power, by forming Treaties with an Indian
tribe or a foreign nation, to legislate over the United
States,” concluding instead that the Treaty Power “cannot
affect the Legislative power of Congress but in a very
small and limited degree.” Id., at 663.
   Other Representatives who participated in the Jay
Treaty debates agreed with Hillhouse that the Treaty
Power had a limited scope. See, e.g., id., at 516 (Rep.
Sedgwick) (classifying the uses of the power as “1. To
                     Cite as: 572 U. S. ____ (2014)                   11

                  THOMAS, J., concurring in judgment

compose and adjust differences, whether to terminate or to
prevent war. 2. To form contracts for mutual security or
defence; or to make Treaties, offensive or defensive. 3. To
regulate an intercourse for mutual benefit, or to form
Treaties of commerce”). James Madison, who opposed the
Jay Treaty as a Representative from Virginia, also took
the opportunity to reiterate his view that “the Treaty-
making power was a limited power.” Id., at 777.
   Other historical evidence from the postratification period
is in accord. For example, Thomas Jefferson’s Senate
Manual of Parliamentary Procedure, drafted while he was
Vice President and therefore president of the Senate,
Bradley 415, noted the need for a treaty to have a nexus to
international intercourse. If a treaty did not “concern the
foreign nation, party to the contract,” then “it would be a
mere nullity res inter alias acta.” Thomas Jefferson’s
Senate Manual (1801), in 9 The Writings of Thomas Jef-
ferson 80–81 (H. Washington ed. 1861). Later, Justice
Story likewise anchored the Treaty Power in intercourse
between nations. J. Story, Commentaries on the Constitu-
tion of the United States 552–553 (abr. ed. 1833). (“The
power ‘to make treaties’ is by the constitution general; and
of course it embraces all sorts of treaties, for peace or war;
for commerce or territory; for alliance or succours; for
indemnity for injuries or payment of debts; for the recogni-
tion or enforcement of principles of public law; and for any
other purposes, which the policy or interests of independ-
ent sovereigns may dictate in their intercourse with each
other”).
   The touchstone of all of these views was that the Treaty
Power is limited to matters of international intercourse.
Even if a treaty may reach some local matters,1 it still
——————
  1 This point remains disputed.      Compare Bradley 456 (contending
that treaties should be subject “to the same federalism restrictions that
12                  BOND v. UNITED STATES

                THOMAS, J., concurring in judgment

must relate to intercourse with other nations. The Jay
Treaty, for example, altered state property law, but only
with respect to British subjects, who could hold and devise
real property in the United States “in like manner as if
they were natives.” Art. IX, 8 Stat. 122. An 1815 treaty
with Great Britain was held to pre-empt a state law au-
thorizing the seizure of “ ‘free negroes or persons of color’ ”
at ports in part because the state law applied to British
sailors. See Elkison v. Deliesseline, 8 F. Cas. 493, 495 (No.
4, 366) (CC SC 1823) (Johnson, Circuit Justice). And
treaties with China and Japan, which afforded subjects of
those countries the same rights and privileges as citizens
of other nations, were understood to pre-empt state laws
that discriminated against Chinese and Japanese subjects.
See, e.g., Baker v. Portland, 2 F. Cas. 472, 474 (No. 777)
(CC Ore. 1879). Cf. Brief for United States 29, 33–38.
  The postratification theory and practice of treaty-
making accordingly confirms the understanding that
treaties by their nature relate to intercourse with other
nations (including their people and property), rather than
to purely domestic affairs.
                            III
  The original understanding that the Treaty Power was
limited to international intercourse has been well repre-
sented in this Court’s precedents. Although we have not
had occasion to define the limits of the power in much
detail, we have described treaties as dealing in some
manner with intercourse between nations. See, e.g.,
Holmes v. Jennison, 14 Pet. 540, 569 (1840) (“The power to
make treaties . . . was designed to include all those sub-
jects, which in the ordinary intercourse of nations had
——————
apply to Congress’s legislative powers”), with Golove 1077 (arguing
treaties can address “subjects that are otherwise beyond Congress’s
legislative powers”).
                  Cite as: 572 U. S. ____ (2014)            13

               THOMAS, J., concurring in judgment

usually been made subjects of negotiation and treaty”);
Holden v. Joy, 17 Wall. 211, 242–243 (1872) (“[T]he fram-
ers of the Constitution intended that [the Treaty Power]
should extend to all those objects which in the intercourse
of nations had usually been regarded as the proper sub-
jects of negotiation and treaty, if not inconsistent with the
nature of our government and the relation between the
States and the United States”). Cf. Power Auth. of N. Y. v.
Federal Power Comm’n, 247 F. 2d 538, 542–543 (CADC
1957) (Bazelon, J.) (“No court has ever said . . . that the
treaty power can be exercised without limit to affect mat-
ters which are of purely domestic concern and do not
pertain to our relations with other nations”), vacated as
moot, 355 U. S. 64 (1957) (per curiam).
   A common refrain in these cases is that the Treaty
Power “extends to all proper subjects of negotiation with
foreign governments.” In re Ross, 140 U. S. 453, 463
(1891); see also Geofroy v. Riggs, 133 U. S. 258, 266 (1890)
(same); Asakura v. Seattle, 265 U. S. 332, 341 (1924)
(same). Those cases identified certain paradigmatic in-
stances of “intercourse” that were “proper negotiating
subjects” fit for treaty. See, e.g., Holmes, supra, at 569
(“[T]he treaty-making power must have authority to de-
cide how far the right of a foreign nation . . . will be recog-
nised and enforced, when it demands the surrender of any
[fugitive] charged with offences against it”); Geofroy, su-
pra, at 266 (“It is also clear that the protection which
should be afforded to the citizens of one country owning
property in another, and the manner in which that prop-
erty may be transferred, devised or inherited, are fitting
subjects for such negotiation and of regulation by mutual
stipulations between the two countries”); Asakura, supra,
at 341 (“Treaties for the protection of citizens of one coun-
try residing in the territory of another are numerous, and
make for good understanding between nations” (footnote
omitted)). Nothing in our cases, on the other hand, sug-
14                    BOND v. UNITED STATES

                  THOMAS, J., concurring in judgment

gests that the Treaty Power conceals a police power over
domestic affairs.
   Whatever its other defects, Missouri v. Holland, 252
U. S. 416 (1920), is consistent with that view. There, the
Court addressed the constitutionality of a treaty that
regulated the capture of birds that migrated between
Canada and the United States. Convention with Great
Britain for the Protection of Migratory Birds, Aug. 16,
1916, 39 Stat. 1702, T. S. No. 628. Although the Court
upheld a statute implementing that treaty based on an
improperly broad view of the Necessary and Proper
Clause, see ante, at 12–14 (SCALIA, J., concurring in judg-
ment), Holland did not conclude that the Treaty Power
itself was unlimited. See 252 U. S., at 433 (“We do not
mean to imply that there are no qualifications to the
treaty-making power . . .”). To the contrary, the holding in
Holland is consistent with the understanding that treaties
are limited to matters of international intercourse. The
Court observed that the treaty at issue addressed mi-
gratory birds that were “only transitorily within the State
and ha[d] no permanent habitat therein.” Id., at 435; see
also id., at 434 (“[T]he treaty deals with creatures that
[only] for the moment are within the state borders”). As
such, the birds were naturally a matter of international
intercourse because they were creatures in international
transit.2
——————
  2 The Solicitor General also defended the treaty in Holland on a basis
that recognized the limited scope of the Treaty Power. Acknowledging
that the Treaty Power addressed “matters in which a foreign govern-
ment may have an interest, and which may properly be the subject of
negotiations with that Government,” Brief for Appellee in Missouri v.
Holland, O. T. 1919, No. 609, p. 41, the Solicitor General expressly
reserved the question “[w]hether a treaty . . . for the protection of game
which remains permanently within the United States would be a valid
exercise of the treaty-making power.” Id., at 42. Because the treaty at
issue focused on creatures in international transit—it was “limited to
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                  THOMAS, J., concurring in judgment

   At least until recently, the original understanding that
the Treaty Power is limited was widely shared outside the
Court as well. See Golove 1288 (“[V]irtually every author-
ity, including the Supreme Court, has on countless occa-
sions from the earliest days recognized general subject
matter limitations on treaties”). The Second Restatement
on the Foreign Relations Law of the United States, for
example, opined that the Treaty Power is available only if
the subject matter of the treaty “is of international con-
cern.” §117(1)(a) (1964–1965). The Second Restatement
explained that a treaty “must relate to the external con-
cerns of the nation as distinguished from matters of a
purely internal nature.” Id., Comment b; see also Treaties
and Executive Agreements: Hearings on S. J. Res. 1 before
a Subcommittee of the Senate Committee on the Judici-
ary, 84th Cong., 1st Sess., 183 (1955) (Secretary of State
Dulles) (Treaties cannot regulate matters “which do not
essentially affect the actions of nations in relation to
international affairs, but are purely internal”); Proceed-
ings of the American Society of International Law 194–196
(1929) (C. Hughes) (“[The Treaty Power] is not a power
intended to be exercised . . . with respect to matters that
have no relation to international concerns”). But see
Restatement (Third) of Foreign Relations Law of the
United States §302, Comment c (“Contrary to what was
once suggested, the Constitution does not require that an
international agreement deal only with ‘matters of inter-
national concern’ ”). At a minimum, the Second Restate-
ment firmly reflects the understanding shared by the
Framers that the Treaty Power has substantive limits.
Only in the latter part of the past century have treaties

——————
 regulations for the protection of birds which regularly migrate between
the United States and Canada”—the Solicitor General concluded that
the treaty concerned “a proper subject of negotiations.” Ibid.
16                BOND v. UNITED STATES

              THOMAS, J., concurring in judgment

challenged that prevailing conception by addressing “mat-
ters that in the past countries would have addressed
wholly domestically” and “purport[ing] to regulate the
relationship between nations and their own citizens,”
Bradley 396; see also ante, at 12 (opinion of SCALIA, J.).
But even the Solicitor General in this case would not go
that far; he acknowledges that “there may well be a line to
be drawn” regarding “whether the subject matter of [a]
treaty is a proper subject for a treaty.” Tr. of Oral Arg.
43:10–15.
                         *    *     *
  In an appropriate case, I would draw a line that respects
the original understanding of the Treaty Power. I ac-
knowledge that the distinction between matters of in-
ternational intercourse and matters of purely domestic
regulation may not be obvious in all cases. But this Court
has long recognized that the Treaty Power is limited, and
hypothetical difficulties in line-drawing are no reason to
ignore a constitutional limit on federal power.
  The parties in this case have not addressed the proper
scope of the Treaty Power or the validity of the treaty
here. The preservation of limits on the Treaty Power is
nevertheless a matter of fundamental constitutional im-
portance, and the Court ought to address the scope of the
Treaty Power when that issue is presented. Given the
increasing frequency with which treaties have begun to
test the limits of the Treaty Power, see Bradley 402–409,
that chance will come soon enough.
                 Cite as: 572 U. S. ____ (2014)           1

                ALITO, J., concurring in judgment

SUPREME COURT OF THE UNITED STATES
                          _________________

                          No. 12–158
                          _________________


    CAROL ANNE BOND, PETITIONER v. UNITED

                  STATES 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE THIRD CIRCUIT

                         [June 2, 2014]


  JUSTICE ALITO, concurring in the judgment.
  As explained in Part I of JUSTICE SCALIA’s concurring
opinion, which I join, petitioner’s conduct violated 18
U. S. C. §229, the federal criminal statute under which she
was convicted. I therefore find it necessary to reach the
question whether this statute represents a constitutional
exercise of federal power, and as the case comes to us, the
only possible source of federal power to be considered is
the treaty power.
  For the reasons set out in Parts I–III of JUSTICE
THOMAS’ concurring opinion, which I join, I believe that
the treaty power is limited to agreements that address
matters of legitimate international concern. The treaty
pursuant to which §229 was enacted, the Chemical Weap-
ons Convention, is not self-executing, and thus the Con-
vention itself does not have domestic effect without con-
gressional action. The control of true chemical weapons,
as that term is customarily understood, is a matter of
great international concern, and therefore the heart of the
Convention clearly represents a valid exercise of the treaty
power. But insofar as the Convention may be read to
obligate the United States to enact domestic legislation
criminalizing conduct of the sort at issue in this case,
which typically is the sort of conduct regulated by the
States, the Convention exceeds the scope of the treaty
2                BOND v. UNITED STATES

               ALITO, J., concurring in judgment

power. Section 229 cannot be regarded as necessary and
proper to carry into execution the treaty power, and ac-
cordingly it lies outside Congress’ reach unless supported
by some other power enumerated in the Constitution. The
Government has presented no such justification for this
statute.
   For these reasons, I would reverse petitioner’s convic-
tion on constitutional grounds.
