                    FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

HUMANITARIAN LAW PROJECT;                 
RALPH FERTIG; ILANKAI THAMIL
SANGAM; TAMILS OF NORTHERN
CALIFORNIA; TAMIL WELFARE AND
HUMAN RIGHTS COMMITTEE;
FEDERATION OF TAMIL SANGAMS OF
NORTH AMERICA; WORLD TAMIL
COORDINATING COMMITTEE;                          No. 05-56753
NAGALINGAM JEYALINGAM, Dr.,
                Plaintiffs-Appellees,            D.C. Nos.
                                               CV-98-01971-ABC
                 v.                            CV-03-06107-ABC
MICHAEL B. MUKASEY,* Attorney
General, of the United States;
UNITED STATES DEPARTMENT OF
JUSTICE; CONDOLEEZA RICE,
Secretary of State; UNITED STATES
DEPARTMENT OF STATE,
            Defendants-Appellants.
                                          




  *Michael B. Mukasey is substituted for his predecessor, Alberto R.
Gonzales, as Attorney General of the United States, pursuant to Fed. R.
App. P. 43(c)(2).

                                16135
16136        HUMANITARIAN LAW PROJECT v. MUKASEY



HUMANITARIAN LAW PROJECT;               
RALPH FERTIG; ILANKAI THAMIL
SANGAM; TAMILS OF NORTHERN
CALIFORNIA; TAMIL WELFARE AND
HUMAN RIGHTS COMMITTEE;
FEDERATION OF TAMIL SANGAMS OF
NORTH AMERICA; WORLD TAMIL
                                              No. 05-56846
COORDINATING COMMITTEE;
NAGALINGAM JEYALINGAM, Dr.,                    D.C. Nos.
               Plaintiffs-Appellants,      CV-98-01971-ABC
                                            CV-03-06107-ABC
                 v.
                                               OPINION
MICHAEL B. MUKASEY,* Attorney
General, of the United States;
UNITED STATES DEPARTMENT OF
JUSTICE; CONDOLEEZA RICE,
Secretary of State; UNITED STATES
DEPARTMENT OF STATE,
             Defendants-Appellees.
                                        
         Appeal from the United States District Court
            for the Central District of California
         Audrey B. Collins, District Judge, Presiding

                   Argued and Submitted
              May 1, 2007—Pasadena, California

                  Filed December 10, 2007

        Before: Harry Pregerson, Sidney R. Thomas, and
             Johnnie B. Rawlinson, Circuit Judges.

                 Opinion by Judge Pregerson
            HUMANITARIAN LAW PROJECT v. MUKASEY         16141
                           COUNSEL

Peter D. Keisler, Assistant Attorney General; Debra Wong
Yang, United States Attorney; Gregory G. Katsas, Deputy
Assistant Attorney General; and Douglas N. Letter, Joshua
Waldman, Appellate Staff, Civil Division, for the defendants-
appellants/appellees.

David Cole, Georgetown University Law Center; Shayna
Kadidal, Center for Constitutional Rights; Carol A. Sobel,
Law Office of Carol A. Sobel; Paul L. Hoffman, Schonbrun,
De Simone, Seplow Harris & Hoffman, LLP; Visuvanathan
Rudrakumaran, Plaintiff World Tamil Coordinating Comm.,
for the plaintiffs-appellees/appellants.


                           OPINION

PREGERSON, Circuit Judge:

   We are once again called upon to decide the constitutional-
ity of sections 302 and 303 of the Antiterrorism and Effective
Death Penalty Act (“AEDPA”) and its 2004 amendment, the
Intelligence Reform and Terrorism Prevention Act
(“IRTPA”).

                      I.   OVERVIEW

   Section 302(a) of AEDPA, Pub. L. 104-132, 110 Stat. 1214
(1996), codified in 8 U.S.C. § 1189, authorizes the Secretary
of State (the “Secretary”) to designate a group as a “foreign
terrorist organization.” Section 303(a) makes it a crime for
anyone to provide support to even the nonviolent activities of
the designated organization. See 18 U.S.C. § 2339B(a). Spe-
cifically, 8 U.S.C. § 1189(a)(1) authorizes the Secretary of
State
16142         HUMANITARIAN LAW PROJECT v. MUKASEY
      to designate an organization as a foreign terrorist
      organization . . . if the Secretary finds that (A) the
      organization is a foreign organization; (B) the orga-
      nization engages in terrorist activity . . . ; and (C) the
      terrorist activity or terrorism of the organization
      threatens the security of United States nationals or
      the national security of the United States.

8 U.S.C. § 1189(a)(1).

   The pertinent facts may be found in prior published deci-
sions in this case. See Humanitarian Law Project v. Reno, 205
F.3d 1130 (9th Cir. 2000) (“HLP I”), cert. denied, 532 U.S.
904 (2001); see also Humanitarian Law Project v. United
States Dep’t of Justice, 352 F.3d 382 (9th Cir. 2003) (“HLP
II”), vacated, 393 F.3d 902 (9th Cir. 2004). We, therefore, set
forth only a brief overview of the facts of this case.

   Plaintiffs are six organizations, a retired federal administra-
tive law judge, and a surgeon. The Kurdistan Workers Party,
a.k.a Partiya Karkeran Kurdistan (“PKK”), and the Liberation
Tigers of Tamil Eelam (“LTTE”) engage in a wide variety of
unlawful and lawful activities. Plaintiffs seek to provide sup-
port only to nonviolent and lawful activities of PKK and
LTTE. This support would help Kurds living in Turkey and
Tamils living in Tamil Eelam in the Northern and Eastern
provinces of Sri Lanka to achieve self-determination.1
  1
    Plaintiffs who support PKK want: (1) to train members of PKK on how
to use humanitarian and international law to peacefully resolve disputes,
(2) to engage in political advocacy on behalf of Kurds who live in Turkey,
and (3) to teach PKK members how to petition various representative
bodies such as the United Nations for relief.
  Plaintiffs who support LTTE want: (1) to train members of LTTE to
present claims for tsunami-related aid to mediators and international
bodies, (2) to offer their legal expertise in negotiating peace agreements
between the LTTE and the Sri Lankan government, and (3) to engage in
political advocacy on behalf of Tamils who live in Sri Lanka.
            HUMANITARIAN LAW PROJECT v. MUKASEY            16143
   On October 8, 1997, the Secretary of State designated
PKK, LTTE, and twenty-eight other foreign organizations as
“foreign terrorist organizations.” See 62 Fed. Reg. 52, 650,
52,650-51 (Oct. 8, 1997). To this day, both PKK and LTTE
remain on the designated foreign terrorist organization list.
Plaintiffs, fearing that they would be criminally investigated,
prosecuted, and convicted under section 2339B(a), have been
withholding their support for the PKK and LTTE from the
time they were designated as foreign terrorist organizations.

   On March 19, 1998, Plaintiffs filed a complaint in the dis-
trict court (CV-98-01971-ABC; appeal No. 05-56753), alleg-
ing that AEDPA violated their First and Fifth Amendment
rights. Plaintiffs sought a preliminary injunction to bar the
government from enforcing against them AEDPA’s prohibi-
tion against providing “material support or resources” to PKK
and LTTE. In support of their motion for a preliminary
injunction, Plaintiffs argued: (1) that AEDPA violated their
First Amendment right to freedom of association and their
Fifth Amendment right to due process because section
2339B(a) imposed a criminal penalty for their association
with the designated organizations without requiring the gov-
ernment to prove that Plaintiffs had the specific intent to fur-
ther the designated organizations’ unlawful goals; (2) that
AEDPA violated their First Amendment right to association
by prohibiting them from making political contributions to the
designated organizations; and (3) that AEDPA violated their
First and Fifth Amendment rights because it gave the Secre-
tary of State unfettered licensing power to designate a group
as a foreign terrorist organization.

   In June 1998, the district court partially granted Plaintiffs’
motion for a preliminary injunction and enjoined the Attorney
General’s enforcement of AEDPA with respect to its prohibi-
tion on providing “training” and “personnel” to PKK and
LTTE. See Humanitarian Law Project v. Reno, 9 F. Supp. 2d
1205, 1215 (C.D. Cal. 1998) (“DC-HLP I”). The district court
held that “Plaintiffs have demonstrated a probability of suc-
16144       HUMANITARIAN LAW PROJECT v. MUKASEY
cess on their claim that the terms ‘personnel’ and ‘training’
are impermissibly vague.” Id. The district court rejected the
remainder of Plaintiffs’ challenges, holding that AEDPA’s
prohibition on providing “material support or resources” to
designated foreign terrorist organizations is a “content-neutral
limitation on Plaintiffs’ right to freedom of association” and
“is subject to an intermediate scrutiny level of review.” Id. at
1212. The district court also held that “AEDPA does not
impose ‘guilt by association alone’ in violation of the First
Amendment because the AEDPA only limits the permissible
ways in which Plaintiffs can associate with PKK and LTTE.”
Id. (emphasis in the original). In other words, the district court
held that AEDPA does not criminalize mere membership.
Rather, AEDPA criminalizes conduct that provides “material
support or resources” to a designated foreign terrorist organi-
zation. Finally, the district court held that Plaintiffs failed to
establish a probability of success on their claim that AEDPA
affords the Secretary of State unfettered discretion to desig-
nate a group as a foreign terrorist organization. See id. at
1213.

   Both parties appealed the district court’s order. On March
3, 2000, we affirmed the district court. See HLP I. In HLP I,
we determined that AEDPA section 2339B is a content-
neutral regulation of conduct subject to intermediate scrutiny.
See id. at 1135. Further, we rejected Plaintiffs’s licensing
scheme argument and held that the discretion accorded to the
Secretary of State to designate a group as a foreign terrorist
organization is not “unfettered” “because the regulation
involves the conduct of foreign affairs” for which the courts
“owe the executive branch even more latitude.” Id. at 1137.
Finally, we agreed with Plaintiffs that AEDPA’s prohibitions
on providing “personnel” and “training” to designated foreign
terrorist organizations were unconstitutionally vague because
these prohibitions could be read to criminalize conduct pro-
tected by the First Amendment. See id. at 1137-38.

  After the case went back to the district court, the govern-
ment moved to dismiss and both parties sought summary
            HUMANITARIAN LAW PROJECT v. MUKASEY            16145
judgment in their favor. The district court re-affirmed its prior
decision in an unpublished order. See Humanitarian Law
Project v. Reno, No. CV 98-01971 ABC, 2001 U.S. Dist.
LEXIS 16729 (C.D. Cal. Oct. 3, 2001). The district court
entered a permanent injunction against enforcing AEDPA’s
prohibition on providing “personnel” and “training” to desig-
nated organizations. See id. at *38. Both parties appealed. On
appeal, in addition to renewing previously raised arguments,
Plaintiffs also raised a Fifth Amendment due process chal-
lenge, arguing that AEDPA section 2339B imposes vicarious
liability because it does not contain a mens rea element.

   On October 26, 2001, Congress enacted the Uniting and
Strengthening America by Providing Appropriate Tools
Required to Intercept and Obstruct Terrorism Act (“USA
PATRIOT Act”), Pub. L. No. 107-56, § 805(a)(2), 115 Stat.
272 (Oct. 26, 2001). The USA PATRIOT Act amended
AEDPA’s definition of “material support or resources” to
include the prohibition against providing “expert advice or
assistance” to a designated foreign terrorist organization. See
18 U.S.C. § 2339A(b) and § 2339B(g)(4).

   On August 27, 2003, Plaintiffs filed a separate complaint in
the district court (CV-03-06107-ABC; appeal No. 05-56846),
challenging AEDPA’s ban on providing “expert advice or
assistance” to a designated foreign terrorist organization. The
district court found that term to be unconstitutionally vague,
but not overbroad. See Humanitarian Law Project v. Ashcroft,
309 F. Supp. 2d 1185 (C.D. Cal. 2004). The district court
granted Plaintiffs’s request for injunctive relief. See id. at
1204. Both parties appealed.

   On December 3, 2003, we affirmed the district court’s
holding that the terms “training” and “personnel” were void
for vagueness. See Humanitarian Law Project v. United
States Dep’t of Justice, 352 F.3d 382 (9th Cir. 2003) (“HLP
II”), vacated, 393 F.3d 902 (9th Cir. 2004). A majority of the
panel also read into the statute a mens rea requirement hold-
16146       HUMANITARIAN LAW PROJECT v. MUKASEY
ing that, “to sustain a conviction under § 2339B, the govern-
ment must prove beyond a reasonable doubt that the donor
had knowledge that the organization was designated by the
Secretary as a foreign terrorist organization or that the donor
had knowledge of the organization’s unlawful activities that
caused it to be so designated.” Id. at 403. The parties sought,
and we granted, en banc review of HLP II. See Humanitarian
Law Project v. United States Dep’t of Justice, 382 F.3d 1154
(9th Cir. 2004).

  On December 17, 2004, three days after the en banc panel
heard oral argument, Congress passed the Intelligence Reform
and Terrorism Prevention Act (“IRTPA”) which amended
AEDPA. As amended, AEDPA now provides in part:

    Whoever knowingly provides material support or
    resources to a foreign terrorist organization, or
    attempts or conspires to do so, shall be fined under
    this title or imprisoned not more than 15 years, or
    both, and, if the death of any person results, shall be
    imprisoned for any term of years or for life.

18 U.S.C. § 2339B(a)(1) (emphasis added).

  The term “material support or resources” includes:

    any property, tangible or intangible, or service,
    including currency or monetary instruments or finan-
    cial securities, financial services, lodging, training,
    expert advice or assistance, safehouses, false docu-
    mentation or identification, communications equip-
    ment, facilities, weapons, lethal substances,
    explosives, personnel (1 or more individuals who
    may be or include oneself), and transportation,
    except medicine or religious materials.

18 U.S.C. § 2339A(b) (emphasis added).
              HUMANITARIAN LAW PROJECT v. MUKASEY                  16147
   In enacting IRTPA, Congress amended the definition of
“material support or resources” to include an additional ban
on providing “service.” See id. Congress also defined for the
first time the terms “training” and “expert advice or assis-
tance,” 18 U.S.C. § 2339(A)(b)(2)-(3), and clarified the prohi-
bition against providing “personnel” to designated
organizations, 18 U.S.C. § 2339B(h).

   Post-IRTPA, “training” refers to “instruction or teaching
designed to impart a specific skill, as opposed to general
knowledge.” 18 U.S.C. § 2339A(b)(2). “Expert advice or
assistance” encompasses “advice or assistance derived from
scientific, technical or other specialized knowledge.” 18
U.S.C. § 2339A(b)(3). “Personnel” includes “1 or more indi-
viduals” who “work under th[e] terrorist organization’s direc-
tion or control or [who] organize, manage, supervise, or
otherwise direct the operation of that organization.” 18 U.S.C.
§ 2339B(h). AEDPA, as amended by IRTPA, narrows the
definition of “personnel” by providing that “[i]ndividuals who
act entirely independently of the foreign terrorist organization
to advance its goals or objectives shall not be considered to
be working under the foreign terrorist organization’s direction
or control.” Id. (emphasis added).

   Further, IRTPA provides that AEDPA’s prohibition on pro-
viding “material support or resources” to a designated foreign
terrorist organization includes a mens rea requirement. To
violate the statute, a person who provides “material support or
resources” to a designated organization must know that (1)
“the organization is a designated terrorist organization,”(2)
“the organization has engaged or engages in terrorist activi-
ty,” or that (3) “the organization has engaged or engages in ter-
rorism.”2 18 U.S.C. § 2339B(a)(1).
  2
    This language essentially adopts our holding in HLP II, where we held
that “to sustain a conviction under § 2339B, the government must prove
beyond a reasonable doubt that the donor had knowledge that the organi-
zation was designated by the Secretary as a foreign terrorist organization
or that the donor had knowledge of the organization’s unlawful activities
that caused it to be so designated.” HLP II, 352 F.3d at 403.
16148         HUMANITARIAN LAW PROJECT v. MUKASEY
   Lastly, AEDPA, as amended by IRTPA, gives the Secre-
tary of State discretion to authorize (with the concurrence of
the Attorney General) certain forms of support3 otherwise pro-
scribed under section 2339B(a) unless such support “may be
used to carry out terrorist activity.” 18 U.S.C. § 2339B(j).

   Because of the amendments to AEDPA contained in
IRTPA, the en banc panel, on December 21, 2004, “vacate[d]
the judgment and injunction [of the HLP II panel] regarding
the terms ‘personnel’ and ‘training,’ and remanded [this case]
to the district court for further proceedings.” See Humanitar-
ian Law Project v. United States Dep’t of State, 393 F.3d 902,
902 (9th Cir. 2004) (“HLP en banc”). The en banc panel also
affirmed the district court’s rulings on the rest of Plaintiffs’
First Amendment challenges “for the reasons set out in [HLP
I],” and vacated the decision in HLP II. Id. On April 1, 2005,
we remanded Plaintiffs’ separate challenge to the term “expert
advice or assistance” to the district court to consider IRTPA’s
impact on the litigation.

   On remand, the district court consolidated the two cases
(the “personnel” and “training” challenge and the “expert
advice and assistance” challenge). Plaintiffs also challenge
IRTPA’s newly added term “service.” The parties thereafter
filed cross-motions for summary judgment. On July 25, 2005,
the district court granted in part and denied in part the sum-
mary judgment motions in the consolidated cases. See
Humanitarian Law Project v. Gonzales, 380 F. Supp. 2d 1134
(C.D. Cal. 2005) (“DC-HLP III”). The district court held that
the terms “training” and “service” are unconstitutionally
vague. Id. at 1152. With respect to the term “expert advice or
assistance,” the district court held that the “other specialized
knowledge” part of the definition is void for vagueness, but
that the “scientific” and “technical” knowledge part of the
  3
    Section 2339B(j) allows the Secretary of State to exempt from prosecu-
tion persons who may otherwise be held liable for providing “training,”
“expert advice or assistance,” and “personnel.” 18 U.S.C. § 2339B(j).
            HUMANITARIAN LAW PROJECT v. MUKASEY            16149
definition was not vague. Id. at 1151 & n.23. The district
court also held that the newly-added definition of “personnel”
found in AEDPA section 2339B(h) cured the vagueness of
that term. Id. at 1152. The district court rejected the rest of
Plaintiffs’ challenges and granted partial summary judgment
for the government. See id. at 1155. Both parties timely
appealed.

               II.   STANDARD OF REVIEW

   We review the district court’s order granting summary
judgment de novo. See Balint v. Carson City, 180 F.3d 1047,
1050 (9th Cir. 1999) (en banc). We must determine, viewing
the evidence in the light most favorable to the nonmoving
party, whether the district court correctly applied the relevant
substantive law and whether there are any genuine issues of
material fact. See id.

   The district court’s determination that a statute is unconsti-
tutionally vague is reviewed de novo. See United States v.
Wyatt, 408 F.3d 1257, 1260 (9th Cir. 2005).

                     III.   DISCUSSION

  A.   Specific Intent

   In their prior appeals, Plaintiffs argued that AEDPA section
2339B(a) violates their Fifth Amendment due process rights
because that section does not require proof of mens rea to
convict a person for providing “material support or resources”
to a designated foreign terrorist organization. See HLP-II, 352
F.3d at 394. In HLP-II, we read the statute to require that the
donor of the “material support or resources” have knowledge
“either of an organization’s designation or of the unlawful
activities that caused it to be so designated.” Id. at 402-03.

 In December 2004, Congress passed IRTPA that revised
AEDPA to essentially adopt our reading of AEDPA section
16150       HUMANITARIAN LAW PROJECT v. MUKASEY
2339B to include a knowledge requirement. Thus, post-
IRTPA, to convict a person for providing “material support or
resources” to a designated foreign terrorist organization, the
government must prove that the donor defendant “ha[d]
knowledge that the organization is a designated terrorist orga-
nization, that the organization has engaged or engages in ter-
rorist activity, or that the organization has engaged or engages
in terrorism.” 18 U.S.C. § 2339B(a) (citations omitted). As
explained above, on December 21, 2004, the en banc panel
vacated our judgment in HLP II, and remanded the case to the
district court for further proceedings in light of IRTPA. See
HLP en banc, 393 F.3d 902. The district court’s decision on
remand is now the matter before us.

   Plaintiffs argue that IRTPA does not sufficiently cure
AEDPA section 2339B’s mens rea deficiency. They contend
that section 2339B(a) continues to violate due process
because it does not require the government to prove that the
donor defendant acted with specific intent to further the ter-
rorist activity of the designated organization. Plaintiffs urge
us to invalidate the statute or, alternatively, to read a specific
intent requirement into the statute.

   [1] “In our jurisprudence guilt is personal.” Brown v.
United States, 334 F.2d 488, 495 (9th Cir. 1964) (internal
quotations and citation omitted). Thus, we must “construe [a
criminal] statute in light of the fundamental principle that a
person is not criminally responsible unless ‘an evil-meaning
mind’ accompanies ‘an evil-doing hand.’ ” United States v.
Nguyen, 73 F.3d 887, 890 (9th Cir. 1995) (quoting Morissette
v. United States, 342 U.S. 246, 251 (1952)). In other words,
unless Congress expressly communicates its intent to dispense
with a mens rea requirement and create strict criminal liabil-
ity, the notion of “personal guilt” requires some culpable
intent before criminal liability attaches.

   “[D]etermining the mental state required for commission of
a federal crime requires ‘construction of the statute and . . .
              HUMANITARIAN LAW PROJECT v. MUKASEY                    16151
inference of the intent of Congress.’ ” Staples v. United
States, 511 U.S. 600, 605 (1994) (quoting United States v.
Balint, 258 U.S. 250, 253 (1922)). We remain mindful that we
“should not enlarge the reach of enacted crimes by constitut-
ing them from anything less than the incriminating compo-
nents contemplated by the words used in the statute.”
Morissette, 342 U.S. at 263.

   In Liparota v. United States, 471 U.S. 419 (1985), the
Supreme Court examined the constitutionality of a federal
statute that criminalized the acquisition or possession of food
stamps in any unauthorized manner. See id. at 420-21. The
statute contained no explicit mens rea requirement. The Court
read into the statute the requirement that the government
prove that “the defendant knew his conduct to be unauthorized
by statute or regulations.” Id. at 425-26 (emphasis added)
(noting that “to interpret the statute otherwise would be to
criminalize a broad range of apparently innocent conduct”).4

   [2] Here, AEDPA section 2339B(a) already requires the
government to prove that the donor defendant provided “ma-
terial support or resources” to a designated foreign terrorist
organization with knowledge that the donee organization is a
designated foreign terrorist organization, or with knowledge
that the organization is or has engaged in terrorist activities or
terrorism. 18 U.S.C. § 2339B(a). As amended, AEDPA sec-
tion 2339B(a) complies with the “conventional requirement
   4
     The other two cases Plaintiffs rely on, Staples, 511 U.S. 600, and
United States v. X-Citement Video, Inc., 513 U.S. 64 (1994), also involved
statutes that did not contain an explicit mens rea requirement. In Staples,
the Supreme Court interpreted the statute punishing possession of an
unregistered machine gun to require knowledge that the gun he or she pos-
sessed is unregistered. See Staples, 511 U.S. at 619. Similarly, in X-
Citement Video, the Court interpreted the term “knowingly” to require that
defendant knew that the persons appearing in a sexually explicit video
were minors. See X-Citement Video, 513 U.S. at 78. However, as in Lipa-
rota, the Court required that, in the absence of a specific mens rea require-
ment, the government prove the defendant acted knowingly.
16152         HUMANITARIAN LAW PROJECT v. MUKASEY
for criminal conduct — awareness of some wrongdoing.” Sta-
ples, 511 U.S. at 606-07. Thus, a person with such knowledge
is put on notice that “providing material support or resources”
to a designated foreign terrorist organization is unlawful.
Accordingly, we hold that the amended version of section
2339B comports with the Fifth Amendment’s requirement of
“personal guilt.”

    [3] Plaintiffs urge us to read a specific intent requirement
into AEDPA section 2339B. They rely on Scales v. United
States, 367 U.S. 203 (1961). In Scales, the Supreme Court
held that it was wrong to impute criminal guilt based on mem-
bership in an organization without proof that the defendant
acted with culpable intent. See id. at 224-25. As amended,
section 2339B(a) does not proscribe membership in or associ-
ation with the terrorist organizations,5 but seeks to punish only
those who have provided “material support or resources” to a
foreign terrorist organization with knowledge that the organi-
zation was a designated foreign terrorist organization, or that
it is or has engaged in terrorist activities or terrorism. Accord-
ingly, unlike the statute in Scales which was silent with
respect to requisite mens rea, section 2339B(a) exposes one
to criminal liability only where the government proves that
the donor defendant acted with culpable intent — knowledge.

   At oral argument, Plaintiffs conceded that, were we to read
into section 2339B a specific intent requirement that the per-
son providing “material support or resources” do so with an
intent to further the organization’s unlawful goals (terrorist
activity), we would be extending Scales. Because we find that
acting with “knowledge” satisfies the requirement of “per-
sonal guilt” and eliminates any due process concerns, we
decline Plaintiffs’ invitation to extend the holding in Scales.
   5
     Although section 2339B(a) does not punish mere membership, the stat-
ute does prohibit the paying of membership dues. See HLP I, 205 F.3d at
1134 (rejecting Plaintiffs’ argument that “the First Amendment requires
the government to demonstrate a specific intent to aid an organization’s
illegal activities before attaching liability to the donation of funds[ ]”).
            HUMANITARIAN LAW PROJECT v. MUKASEY            16153
   Plaintiffs also rely on what they consider “vicarious crimi-
nal liability” cases where courts required proof of intent to
further the group’s illegal ends. Those cases are distinguish-
able. We disagree with Plaintiffs’ characterization of section
2339B(a) as a statute that imposes “vicarious criminal liabili-
ty.”

   [4] Vicarious liability involves holding one person account-
able for the actions of another. Section 2339B(a) criminalizes
the act of knowingly providing “material support or
resources” to a designated foreign terrorist organization.
Donor defendants are penalized for the criminal act of sup-
port. Donor defendants cannot be penalized under section
2339B(a) for the illegal conduct of the donee organization.

   Ferguson v. Estelle, 718 F.2d 730 (5th Cir. 1983), is
instructive. In Ferguson, defendants, participants in a violent
riot, were prosecuted for arson committed by other rioters.
See id. at 731-32. The court held that the state (Texas) could
prosecute the defendants for arson even though they were not
the arsonists. See id. at 731. The court noted that the statute
at issue conformed with Scales’s requirement of personal guilt
because, to obtain a conviction, the state had to prove that the
accused riot participants had specific intent to further the ille-
gal aims of the rioters who committed arson. Id. at 736.

   [5] Unlike the statute at issue in Ferguson, section
2339B(a) seeks to punish only those who commit the acts pro-
scribed by the statute. In other words, a person who provides
“material support or resources” to a designated foreign terror-
ist organization is liable for knowingly doing so in violation
of section 2339B(a). Section 2339B(a) does not impose “vi-
carious criminal liability” because the statute cannot be
invoked to punish the donor defendant for crimes committed
by the donee foreign terrorist organization. A person cannot
be convicted of murder under section 2339B(a) if the foreign
terrorist organization committed an act of terrorism that took
innocent lives. In sum, because section 2339B(a) does not
16154         HUMANITARIAN LAW PROJECT v. MUKASEY
impose “vicarious criminal liability,” due process is satisfied
without proof of specific intent to further the organization’s
illegal goals.

   Finally, in enacting IRTPA, Congress explicitly stated that
knowledge of the organization’s designation as a foreign ter-
rorist organization, or knowledge of its engagement in terror-
ist activities or terrorism is required to convict under section
2339B(a). As the district court correctly observed, Congress
could have, but chose not to, impose a requirement that the
defendant act with the specific intent to further the terrorist
activity of the organization, a requirement clearly set forth in
sections 2339A and 2339C of the statute, but left out of sec-
tion 2339B. See DC HLP III, 380 F. Supp. 2d at 1146. More-
over, it is not our role to rewrite a statute, and we decline to
do so here. See HLP I, 205 F.3d at 1137-38.

   Because there is no Fifth Amendment due process viola-
tion, we affirm the district court on this issue.

  B.     Vagueness

   [6] AEDPA section 2339B(a), as amended by IRTPA in
December 2004, now criminalizes the act of knowingly pro-
viding “material support or resources” to a designated foreign
terrorist organization. The amended statute defines “material
support and resources” as:

       any property, tangible or intangible, or service,
       including currency or monetary instruments or finan-
       cial securities, financial services, lodging, training,
       expert advice or assistance, safehouses, false docu-
       mentation or identification, communications equip-
       ment, facilities, weapons, lethal substances,
       explosives, personnel (1 or more individuals who
       may be or include oneself), and transportation,
       except medicine or religious materials.
            HUMANITARIAN LAW PROJECT v. MUKASEY           16155
18 U.S.C. § 2339A(b) (emphasis added).

   Plaintiffs argue that this amended definition is impermiss-
ibly vague because the statute fails to notify a person of ordi-
nary intelligence as to what conduct constitutes “material
support or resources.” Specifically, Plaintiffs argue that the
prohibitions on providing “training,” “expert advice or assis-
tance,” “service,” and “personnel” to designated organizations
are vague because they are unclear and could be interpreted
to criminalize protected speech and expression.

   The Due Process Clause of the Fifth Amendment requires
that statutes clearly delineate the conduct they proscribe. See
Foti v. City of Menlo Park, 146 F.3d 629, 638 (9th Cir. 1998).
While due process does not “require ‘impossible standards’ of
clarity,” Kolender v. Lawson, 461 U.S. 352, 361 (1983), the
“requirement for clarity is enhanced when criminal sanctions
are at issue or when the statute abut[s] upon sensitive areas of
basic First Amendment freedoms,” Info. Providers’ Coal. for
the Def. of the First Amendment v. FCC, 928 F.2d 866, 874
(9th Cir. 1991) (alteration in original) (internal quotation
marks omitted). In such cases, the statute “must be suffi-
ciently clear so as to allow persons of ordinary intelligence a
reasonable opportunity to know what is prohibited.” HLP I,
205 F.3d at 1137 (quoting Foti, 146 F.3d at 638) (internal
quotation marks omitted). Moreover, “[b]ecause First Amend-
ment freedoms need breathing space to survive, government
may regulate in the area only with narrow specificity.” Foti,
146 F.3d at 638-39 (internal quotation marks omitted).

   Vague statutes are invalidated for three reasons: “(1) to
avoid punishing people for behavior that they could not have
known was illegal; (2) to avoid subjective enforcement of
laws based on ‘arbitrary and discriminatory enforcement’ by
government officers; and (3) to avoid any chilling effect on
the exercise of First Amendment freedoms.” Id. at 638.
16156       HUMANITARIAN LAW PROJECT v. MUKASEY
     1.   “Training”

   In HLP I, we held that the term “training” under AEDPA
was unconstitutionally vague. 205 F.3d at 1138. At the time
of Plaintiffs’ initial challenge in 1998, AEDPA provided no
definition of the term “training.” After we issued our opinion
in HLP I in 2000, Congress amended the statute and defined
the term “training” as “instruction or teaching designed to
impart a specific skill, as opposed to general knowledge.” 18
U.S.C. § 2339A(b)(2). On remand, Plaintiffs argued to the
district court that the term “training” as defined by IRTPA
remains unconstitutionally vague. Plaintiffs contended that
persons of ordinary intelligence must discern whether the
topic they wish to teach to members of designated organiza-
tions amounts to “teaching designed to impart a specific
skill,” which is criminalized, or “general knowledge,” which
is not. Specifically, Plaintiffs contended that they must guess
whether training PKK members in how to use humanitarian
and international human rights law to seek peaceful resolution
of ongoing conflict amounts to teaching a “specific skill” or
“general[ized] knowledge.”

   The district court again agreed with Plaintiffs. The district
court held that IRTPA did not cure the vagueness of the term
“training,” and enjoined the government from enforcing
against Plaintiffs AEDPA’s ban on providing “training.” See
DC-HLP III, 380 F. Supp. 2d at 1150, 1156. We agree.

   Generally, we would start our vagueness analysis by con-
sidering the plain meaning of the language at issue. See John-
son v. Aljian, 490 F.3d 778, 780 (9th Cir. 2007). However,
where Congress expressly defines a term, the definition pro-
vided by Congress guides our vagueness analysis. See United
States. v. Rowland, 464 F.3d 899, 905 (9th Cir. 2006).

  [7] To survive a vagueness challenge, the statute must be
sufficiently clear to put a person of ordinary intelligence on
notice that his or her contemplated conduct is unlawful. See
              HUMANITARIAN LAW PROJECT v. MUKASEY                16157
Foti, 146 F.3d at 638. Because we find it highly unlikely that
a person of ordinary intelligence would know whether, when
teaching someone to petition international bodies for tsunami-
related aid, one is imparting a “specific skill” or “general
knowledge,” we find the statute’s proscription on providing
“training” void for vagueness. See HLP I, 205 F.3d at 1138
(finding the term “training” impermissibly vague because “a
plaintiff who wishes to instruct members of a designated
group on how to petition the United Nations to give aid to
their group could plausibly decide that such protected expres-
sion falls within the scope of the term ‘training.’ ”); see also
Info. Providers’ Coalition, 928 F.2d at 874.

   [8] Even if persons of ordinary intelligence could discern
between the instruction that imparts a “specific skill,” as
opposed to one that imparts “general knowledge,” we hold
that the term “training” would remain impermissibly vague.
As we previously noted in HLP I, limiting the definition of
the term “training” to the “imparting of skills” does not cure
unconstitutional vagueness because, so defined, the term
“training” could still be read to encompass speech and advo-
cacy protected by the First Amendment. See HLP I, 205 F.3d
at 1138 (finding “training” void for vagueness because “it is
easy to imagine protected expression that falls within the
bounds of this term”).6

   For the foregoing reasons, we reject the government’s chal-
lenge and agree with the district court that the term “training”
remains impermissibly vague because it “implicates, and
potentially chills, Plaintiffs’ protected expressive activities
and imposes criminal sanctions of up to fifteen years impris-
onment without sufficiently defining the prohibited conduct
  6
    In deciding previously raised challenges such as vagueness, we are
bound by our decision in HLP I. See Murdoch v. Castro, 489 F.3d 1063,
1067 (9th Cir. 2007) (“ ‘[W]hen a court decides upon a rule of law, that
decision should continue to govern the same issues in subsequent stages
in the same case.’ ”).
16158       HUMANITARIAN LAW PROJECT v. MUKASEY
for ordinary people to understand.” DC-HLP III, 380 F. Supp.
2d at 1150 (citing Info. Providers’ Coalition, 928 F.2d at
874).

    2.   “Expert Advice or Assistance”

   The district court previously invalidated the undefined term
“expert advice or assistance” on vagueness grounds. The dis-
trict court reasoned that the prohibition against providing “ex-
pert advice or assistance” could be construed to criminalize
activities protected by the First Amendment. Id. at 1151. The
government appealed. We now have the benefit of IRTPA’s
language while reviewing this appeal.

  [9] IRTPA defines the term “expert advice or assistance” as
imparting “scientific, technical, or other specialized knowl-
edge.” 18 U.S.C. § 2339A(b)(3).

   The government argues that the ban on “expert advice or
assistance” is not vague. The government relies on the Federal
Rules of Evidence’s definition of expert testimony as testi-
mony based on “scientific, technical, or other specialized
knowledge.” Fed. R. Evid. 702; see also Daubert v. Merrell
Dow Pharm., Inc., 509 U.S. 579, 589-91 (1993). The govern-
ment argues that this definition gives a person of ordinary
intelligence reasonable notice of conduct prohibited under the
statute. Plaintiffs contend that the definition of “expert advice
or assistance” is vague as applied to them because they cannot
determine what “other specialized knowledge” means.

   [10] We agree with the district court that “the Federal Rules
of Evidence’s inclusion of the phrase ‘scientific, technical, or
other specialized knowledge’ does not clarify the term ‘expert
advice or assistance’ for the average person with no back-
ground in law.” DC-HLP III, 380 F. Supp. 2d at 1151.

  [11] At oral argument, the government stated that filing an
amicus brief in support of a foreign terrorist organization
            HUMANITARIAN LAW PROJECT v. MUKASEY            16159
would violate AEDPA’s prohibition against providing “expert
advice or assistance.” Because the “other specialized knowl-
edge” portion of the ban on providing “expert advice or assis-
tance” continues to cover constitutionally protected advocacy,
we hold that it is void for vagueness. See HLP I, 205 F.3d at
1137-38; NAACP v. Button, 371 U.S. 415, 432-33 (1963)
(noting that vagueness and overbreadth depend on “the danger
of tolerating, in the area of First Amendment freedoms, the
existence of a penal statute susceptible of sweeping and
improper application”).

   [12] The portion of the “expert advice or assistance” defini-
tion that refers to “scientific” and “technical” knowledge is
not vague. Unlike “other specialized knowledge,” which cov-
ers every conceivable subject, the meaning of “technical” and
“scientific” is reasonably understandable to a person of ordi-
nary intelligence. See Houghton Mifflin Reading Spelling and
Vocabulary Word Lists (5th Grade), http://www-
kes.stjohns.k12.fl.us/wordlists/5th/vocab2.htm         (including
“technical” as a fifth-grade vocabulary word); see also Ten-
nessee Department of Education Third Grade Science Vocab-
ulary,            http://jc-schools.net/tutorials/vocab/sci-3.htm
(including “scientific method” on third-grade vocabulary list).

    3.   “Service”

   [13] IRTPA amended the definition of “material support or
resources” to add the prohibition on rendering “service” to a
designated foreign terrorist organization. There is no statutory
definition of the term “service.”

  Plaintiffs argue that proscribing “service” is vague because
each of the other challenged provisions could be construed as
a provision of “service.” The district court agreed.

   [14] We adopt the district court’s holding and its reasoning.
See DC-HLP III, 380 F. Supp. 2d at 1151-52. The term “ser-
vice” presumably includes providing members of PKK and
16160       HUMANITARIAN LAW PROJECT v. MUKASEY
LTTE with “expert advice or assistance” on how to lobby or
petition representative bodies such as the United Nations.
“Service” would also include “training” members of PKK or
LTTE on how to use humanitarian and international law to
peacefully resolve ongoing disputes. Thus, we hold that the
term “service” is impermissibly vague because “the statute
defines ‘service’ to include ‘training’ or ‘expert advice or
assistance,’ ” and because “ ‘it is easy to imagine protected
expression that falls within the bounds’ of the term ‘ser-
vice.’ ” Id. at 1152.

    4.   “Personnel”

   In HLP I, we concluded that “personnel” was impermiss-
ibly vague because the term could be interpreted to encom-
pass expressive activity protected by the First Amendment.
HLP I, 205 F.3d at 1137. We stated that, “[i]t is easy to see
how someone could be unsure about what AEDPA prohibits
with the use of the term ‘personnel,’ as it blurs the line
between protected expression and unprotected conduct.” Id.
We observed that “[s]omeone who advocates the cause of the
PKK could be seen as supplying them with personnel . . . .
But advocacy is pure speech protected by the First Amend-
ment.” Id.

   As stated above, in 2004, Congress passed IRTPA which
amended AEDPA. IRTPA added a limitation to the ban on
providing “personnel.” 18 U.S.C. § 2339B(h). Section
2339B(h) clarifies that section 2339B(a) criminalizes provid-
ing “personnel” to a foreign terrorist organization only where
a person, alone or with others, “[work]s under that terrorist
organization’s direction or control or . . . organize[s], man-
age[s], supervise[s], or otherwise direct[s] the operation of
that organization.” Section 2339B(h) also states that the ban
on “personnel” does not criminalize the conduct of
“[i]ndividuals who act entirely independently of the foreign
terrorist organization to advance its goals or objectives.” Id.
            HUMANITARIAN LAW PROJECT v. MUKASEY           16161
   [15] As amended by IRTPA, AEDPA’s prohibition on pro-
viding “personnel” is not vague because the ban no longer
“blurs the line between protected expression and unprotected
conduct.” HLP I, 205 F.3d at 1137. Unlike the version of the
statute before it was amended by IRTPA, the prohibition on
“personnel” no longer criminalizes pure speech protected by
the First Amendment. Section 2339B(h) clarifies that Plain-
tiffs advocating lawful causes of PKK and LTTE cannot be
held liable for providing these organizations with “personnel”
as long as they engage in such advocacy “entirely indepen-
dently of th[ose] foreign terrorist organization[s].” 18 U.S.C.
§ 2339B(h).

   [16] Because IRTPA’s definition of “personnel” provides
fair notice of prohibited conduct to a person of ordinary intel-
ligence and no longer punishes protected speech, we hold that
the term “personnel” as defined in IRTPA is not vague.

  C.   Overbreadth

  Plaintiffs argue that the terms “training,” “personnel,” “ex-
pert advice or assistance” and “service” are substantially over-
broad. The district court rejected Plaintiffs’ challenge. See
DC-HLP III, 380 F. Supp.2d at 1152-53. We affirm.

   [17] A statute is facially overbroad when its application to
protected speech is “substantial, not only in an absolute sense,
but also relative to the scope of the law’s plainly legitimate
applications.” Virginia v. Hicks, 539 U.S. 113, 119-20 (2003)
(internal quotation marks and citations omitted). The Supreme
Court held in Hicks that “[r]arely, if ever, will an overbreadth
challenge succeed against a law or regulation that is not spe-
cifically addressed to speech or to conduct necessarily associ-
ated with speech.” Id. at 124. The Court reasoned that the
“concern with chilling protected speech attenuates as the oth-
erwise unprotected behavior that it forbids the State to sanc-
tion moves from pure speech toward conduct.” Id. (internal
quotation marks and citations omitted).
16162       HUMANITARIAN LAW PROJECT v. MUKASEY
   We have previously held that AEDPA’s prohibition against
providing “material support or resources” to a designated
organization “is not aimed at interfering with the expressive
component of [Plaintiffs’] conduct but at stopping aid to ter-
rorist groups.” HLP I, 205 F.3d at 1135. Thus, because the
statute is not aimed primarily at speech, an overbreadth chal-
lenge is more difficult to show. However, we still conduct the
Hicks analysis. That is, we decide whether the material sup-
port statute’s application to protected speech is substantial
when compared to the scope of the law’s plainly legitimate
applications. See Hicks, 539 U.S. at 118-19.

   [18] Section 2339B(a)’s ban on provision of “material sup-
port or resources” to designated foreign terrorist organizations
undoubtably has many legitimate applications. For instance,
the importance of curbing terrorism cannot be underestimated.
Cutting off “material support or resources” from terrorist
organizations deprives them of means with which to carry out
acts of terrorism and potentially leads to their demise. Thus,
section 2339B(a) can legitimately be applied to criminalize
facilitation of terrorism in the form of providing foreign ter-
rorist organizations with income, weapons, or expertise in
constructing explosive devices. See HLP I, 205 F.3d at 1133.

   The Supreme Court cautioned in Hicks that “there are sub-
stantial social costs created by the overbreadth doctrine when
it blocks application of a law to constitutionally unprotected
speech, or especially to constitutionally unprotected conduct.”
Hicks, 539 U.S. at 119. Were we to restrain the government
from enforcing section 2339B(a) that prohibits individuals in
the United States from providing “material support or
resources” to foreign terrorist organizations, we would poten-
tially be placing our nation in danger of future terrorist
attacks.

   Moreover, although Plaintiffs may be able to identify par-
ticular instances of protected speech that may fall within the
            HUMANITARIAN LAW PROJECT v. MUKASEY           16163
statute, those instances are not substantial when compared to
the legitimate applications of section 2339B(a).

   [19] Thus, because AEDPA section 2339B is not aimed at
expressive conduct and because it does not cover a substantial
amount of protected speech, we hold that the prohibition
against providing “material support or resources” to a foreign
terrorist organization is not facially overbroad.

  D.   Licensing Scheme

   [20] IRTPA added section 2339B(j), an entirely new sec-
tion, to AEDPA. Section 2339B(j) allows the Secretary of
State, with the concurrence of the Attorney General, to grant
approval for individuals and organizations to carry out activi-
ties that would otherwise be considered providing “material
support or resources” to designated foreign terrorist organiza-
tions. 18 U.S.C. § 2339B(j). Section 2339B(j) states that no
one can be prosecuted under the terms “ ‘personnel,’ ‘train-
ing,’ or ‘expert advice or assistance’ if the provision of that
material support or resources to a foreign terrorist organiza-
tion was approved by the Secretary of State with the concur-
rence of the Attorney General.” 18 U.S.C. 2339B(j). The
exception limits the scope of discretion by providing only that
the “Secretary of State may not approve the provision of any
material support that may be used to carry out terrorist activi-
ty.” Id.

   Plaintiffs argue that this provision constitutes an unconsti-
tutional licensing scheme. We disagree.

   Courts may entertain pre-enforcement facial challenges to
a licensing scheme where the law has a “close enough nexus
to expression, or to conduct commonly associated with
expression, to pose a real and substantial threat of the identi-
fied censorship risks.” City of Lakewood v. Plain Dealer
Publ’g Co., 486 U.S. 750, 759 (1988). A licensing scheme is
facially invalid if the “licensing law gives a government offi-
16164       HUMANITARIAN LAW PROJECT v. MUKASEY
cial or agency substantial power to discriminate based on the
content or viewpoint of speech by suppressing disfavored
speech or disliked speaker.” Id. The relevant censorship risks
include “self-censorship by speakers in order to avoid being
denied a license to speak” and the “difficulty of effectively
detecting, reviewing, and correcting content-based censorship
‘as applied’ without standards by which to measure the licen-
sor’s action.” Id.

   In our first decision, we rejected Plaintiffs’ challenge to the
licensing scheme in another portion of AEDPA that allows
the Secretary of State to designate a group as a foreign terror-
ist organization. See HLP I, 205 F.3d at 1136-37. We held
that the Secretary of State’s discretion to designate a group as
a foreign terrorist organization was not unconstitutional. See
id. We reasoned that “AEDPA does not regulate speech or
association per se. Rather, the restriction is on the act of giv-
ing material support to designated foreign organizations.” Id.
at 1136-37. We reach the same conclusion here.

   [21] Section 2339B(j) gives the Secretary of State the dis-
cretion to approve the provision of “material support or
resources.” It does not regulate speech per se. Rather, the stat-
ute permits the Secretary of State to authorize the otherwise
prohibited provision of “material support or resources” to a
designated foreign terrorist organization. Indeed, we clarified
in HLP I that contributions of “material support or resources”
to foreign entities designated as foreign terrorist organizations
should not be equated with political expression and associa-
tion itself, even if such organizations are engaged in political
expression. See HLP I, 205 F.3d at 1134-35 (contrasting the
Buckley doctrine, where monetary support is a proxy for
speech and is therefore a constitutionally protected activity).
Thus, we hold that the discretion given to the Secretary poses
no “real and substantial threat” to Plaintiffs’ protected expres-
sion or their expressive conduct. See City of Lakewood, 486
U.S. at 759.
            HUMANITARIAN LAW PROJECT v. MUKASEY            16165
   We recognize that it is possible for the Secretary to exercise
his or her discretion in a way that discriminates against the
donor of “material support or assistance.” For example, the
Secretary could conceivably exempt from prosecution a per-
son who teaches peacemaking skills to members of Hezbol-
lah, but deny Plaintiffs immunity from prosecution if they
teach the same peacemaking skills to PKK. However, when
evaluating the constitutionality of a licensing scheme, we look
at how closely the prior restraint, on its face, regulates consti-
tutionally protected activity. Here, even though it is possible
for the Secretary to refuse to exercise his or her discretion to
exempt from prosecution a disliked speaker, any such power
is incidental. The statute does not give the Secretary “substan-
tial power to discriminate based on the content or viewpoint
of speech” or the identity of the speaker. Id. (emphasis
added).

   Moreover, in Plaintiffs’ case, any potential for content or
viewpoint-based discrimination or discrimination based on the
identity of the speaker is significantly reduced because the
government is enjoined from enforcing those provisions of the
statute we hold vague. Thus, because Plaintiffs are already
immune from prosecution for protected speech, the danger
that the Secretary can base his or her exercise of discretion on
Plaintiffs’ identity or the content or viewpoint of Plaintiffs’
message is almost non-existent.

   [22] Accordingly, we affirm the district court’s holding that
section 2339B(j) does not have a close enough nexus to pro-
tected speech to allow a facial challenge.

                     IV.   CONCLUSION

   For the foregoing reasons, the judgment of the district court
is AFFIRMED.
