                     Legal and Practical Consequences of a
                               Blockade of Cuba
The President has the power to establish a blockade of Cuba under the laws of the United States
  without further congressional action.
A blockade may be unilaterally established by the United States under international law but its
  establishment may be questioned within the Organization of American States and the United
  Nations. In addition, such a blockade could be regarded by Cuba and other Soviet Bloc nations as an
  act of war.

                                                                                     October 19, 1962

                                          MEMORANDUM*

    This memorandum discusses the legality and practical consequences of a
blockade of Cuba established unilaterally by the United States in response to the
current buildup of a military potential in Cuba with clearly aggressive capabilities.
It concludes that the President has the power to establish such a blockade under the
laws of the United States without further congressional action; that it may be
confined to surface vessels or include aircraft as well; that a blockade may be
unilaterally established by the United States under international law but that its

     *
       Editor’s Note: This unsigned, unaddressed memorandum appears in the daybooks of the Office of
Legal Counsel and was cited in The President’s Constitutional Authority to Conduct Military
Operations Against Terrorists and Nations Supporting Them, 25 Op. O.L.C. 188 (2001).
     Prior to publishing the 2001 opinion, we consulted with officials at the Department of State to
determine whether they had any record or evidence of authorship of this memorandum. Although they
were unable to locate a copy of the memorandum itself, they pointed us to declassified records of a
meeting held on October 19, 1962 (the same date as this memorandum) and attended by a number of
top-level administration officials (including Secretary of State Dean Rusk, Attorney General Robert
Kennedy, and National Security Advisor McGeorge Bundy). See U.S. Dep’t of State, Foreign Relations
of the United States, 1961–1963: Volume XI, Cuban Missile Crisis and Aftermath, doc. 31 (Edward C.
Keefer et al., eds., 1998), available at http://history.state.gov/historicaldocuments/frus1961-63v11/d31
(last visited Aug. 3, 2012) (notes of October 19, 1962 meeting). These records suggest that the memo-
randum may have been prepared by Leonard Meeker, Deputy Legal Adviser for the Department of
State, perhaps in consultation with Nicholas Katzenbach, Deputy Attorney General at the time and
previously Assistant Attorney General for OLC. Mr. Meeker kept the notes that are collected in the
declassified records of the October 19 meeting. According to Mr. Meeker, Mr. Katzenbach spoke first
at the meeting and stated that “the President had ample constitutional and statutory authority to take any
needed military measures.” Id. Mr. Meeker recorded that “my analysis ran along much the same lines.”
Id.
     Mr. Katzenbach’s and Mr. Meeker’s positions were thus consistent with that of this memorandum.
They were also consistent with two other OLC opinions included in this volume—one signed by Robert
Kramer, Assistant Attorney General for OLC, and addressed to Attorney General Kennedy (Authority
of the President to Blockade Cuba, 1 Op. O.L.C. Supp. 195 (Jan. 25, 1961)); the other signed by
Norbert Schlei, Assistant Attorney General for OLC, also addressed to Attorney General Kennedy
(Authority Under International Law to Take Action If the Soviet Union Establishes Missile Bases in
Cuba, 1 Op. O.L.C. Supp. 251 (Aug. 30, 1962)). This memorandum does not cite either of those
opinions, however, which tends to suggest that it was not prepared by the Department of Justice.




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establishment may be questioned within the Organization of American States
(“OAS”) and, perhaps, within the United Nations. In addition, it concludes that
such a blockade could be regarded by Cuba and other Soviet Bloc nations as an act
of war.

                    I. The Legal Requirements of a Blockade

   The most authoritative definition of blockade reads as follows:

      Blockade is the blocking by men-of-war of the approach to the ene-
      my coast, or a part of it, for the purpose of preventing ingress and
      egress of vessels or aircraft of all nations. . . . Although blockade
      is . . . a means of warfare against the enemy, it concerns neutrals as
      well, because the ingress and egress of neutral vessels are thereby in-
      terdicted, and may be punished.

2 L. Oppenheim, International Law: A Treatise 768 (H. Lauterpacht ed., 7th ed.
1952).
    Historically, blockade has been associated with belligerent nations as a measure
of war.
    While the practical effectiveness of a blockade may be influenced by the failure
to interdict aircraft or, presumably, submarines, the legal effectiveness of a
blockade is not affected by the failure to do so. Id. at 781. Thus, a blockade may be
declared against shipping alone, or against shipping and aircraft.
    The formal requirements of a blockade have to do with the manner in which it
is established and its existence made known. The declaration must state the date on
which a blockade begins and must make clear its geographical limits. In addition,
it must satisfy three conditions: (1) it must be effectively maintained; (2) it must
not bar access to ports and coasts of countries not included within its objectives;
and (3) it must be applied impartially to the shipping of all nations.
    The reasons for these conditions are clear. The state declaring the blockade
must be able to make it effective against all shipping to the extent that the risk of
running the blockade is clear and apparent. Otherwise, a so-called “paper block-
ade” would exist and amount to a mere license to commit haphazard acts of
privateering. The element of danger must be clearly understood since, as a matter
of law, any shipping which seeks to run a blockade is liable to seizure and eventual
condemnation by the blockading state.
    A blockade may exclude all shipping and, therefore, all cargoes from the block-
aded state. Alternatively, the blockading state may declare only certain cargoes
contraband.




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                           II. Blockade as an Act of War

   There is a good deal of authority to the effect that a blockade assumes the exist-
ence of a state of war and that there is legally no such thing as a “pacific blockade”
or “a blockade during time of peace.” There are frequent statements by commenta-
tors that a blockade necessarily means war, or depends upon a pre-existing state of
war, or in and of itself creates a state of war. The United States took such a
position with respect to the Anglo-German Blockade of Venezuela in 1902, and
again in 1919, with respect to the proposal that the Allied governments blockade
Bolshevist Russia. Broad statements of this kind, however, require considerable
qualification in the light both of history and of contemporary conditions.

                                      A. History

    During the nineteenth century, a lawyer’s distinction between war and peace
grew up. Since international law was divided between that which existed in
peacetime and that which existed in wartime, it became important to lawyers to
attempt to make a clear distinction. For example, the law of the high seas in
peacetime forbade one nation to stop the shipping of another, but during time of
war freedom of the seas could be heavily circumscribed through rights of blockade
and search and seizure.
    In practice, states never observed the clear-cut distinction between war and
peace which lawyers insisted must exist. Whenever a state had a limited objective
in its use of force, it customarily refrained from declaring war, which implied all-
out hostilities rather than limited action. Often these were referred to as “acts short
of war,” “hostile measures short of war,” or “reprisals short of war.” The lawyers,
however, kept insisting that as a matter of strict logic there could be no such thing.
    There are numerous examples. On several occasions, the United States used
armed force to protect American property abroad against the will of the state
involved without a declaration of war. One such instance was the bombardment
and occupation of Vera Cruz, which Mexico insisted was an act of war, though the
United States maintained that no state of war existed. Other states engaged in
similar practices; Corfu is another famous example.
    In 1902, the British engaged in a blockade of Venezuela as a measure to en-
force the collection of a debt. The United States insisted that a blockade required a
declaration of war and demanded that the British either cease the blockade or
declare war on Venezuela. Eventually the British did, and only after they had done
so did the United States recognize the legality of the blockade.
    The declaration of a state of war was helpful in ascertaining the rights and
obligations of neutrals in a given situation. Apart from this, however, it served
little function. War itself, whatever its reason, was legal self-help, and so were
lesser measures if such could be said to exist.




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    Whether or not a nation declared a state of war it would be found by others to
exist if that state were claiming rights, such as blockade, normally associated with
war. Therefore, it seems to me that legal doctrine to the effect that blockade
requires a state of war is utterly tautological. Blockade is a right that existed only
during war since it was doctrinally related to wartime rather than peacetime. One
could deduce a state of war from the existence of a blockade. And one could not
conceptually claim rights of blockade without acknowledging its relationship to
war. Thus the declaration of war really had no significance apart from clarification
that one was claiming the rights normally associated with blockade under interna-
tional law rather than exceptional rights which would have been unprecedented
interference with freedom of the high seas during peacetime.
    Applied to the current situation, one could say that if the United States declared
a blockade and asserted the rights with respect to neutrals normally associated with
it, there would be no need to declare a state of war as well. Other states might
insist, as we did in the case of Venezuela, that we declare a state of war, but it is
difficult to see the significance of this insistence in any realistic terms should we
refuse to do so. Alternatively, they could state that war existed by virtue of the fact
that we have declared a blockade, whether we affirmed the state of war or not.
    In the light of these facts, what we say with respect to the existence or nonex-
istence of a state of war is largely a political judgment. I would recommend,
therefore, that if we declare a blockade, we simply claim all the rights a blockad-
ing nation would have if a state of war existed. This clarifies our position suffi-
ciently for legal purposes. A number of states will say this amounts to a declara-
tion of war against Cuba, but that could scarcely be avoided under any
circumstances.

                           B. Contemporary Conditions

    In actuality the existence or non-existence of a state of war has always been a
question of fact, not of law. If actual hostilities exist, then such parts of the law of
war as treatment of prisoners, etc., exist irrespective of any formal declaration and
irrespective of the legality or illegality of the hostilities themselves. Moreover, the
distinction between war and peace, as it existed in the nineteenth century, has
limited application today. Various acts are made unlawful by the U.N. Charter, a
sharp distinction from the nineteenth century view that war was itself a lawful
prerogative of states. The significance, therefore, from a legal point of view of a
declaration of war is less important, since it does not make acts in violation of the
Charter lawful.
    One pertinent example of this state of affairs is the blockade of shipping insti-
tuted by Egypt against Israel. Egypt sought to invoke its declared state of war with
Israel as a justification for the blockade. The Security Council, without questioning
or commenting upon the existence of a state of war, declared the blockade to be
unlawful under the Charter.



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   The legality today of a blockade unilaterally imposed by one state upon another
depends upon its compatibility with the language and principles of the Charter.
Ordinarily it, like other measures involving force, is reserved to the United Nations
or to regional organizations such as the OAS. If imposed unilaterally without prior
approval it must be considered a reasonable measure under the circumstances,
proportional to the threat posed, and limited to a legitimate purpose. It does not
become more or less lawful on the basis of declaration of war or a failure to
declare war.
   The irrelevancy of a declaration of war is further supported by the fact that
institution of a blockade is a measure granted expressly to the United Nations and
by inference to the OAS under their respective charters, but nothing is said about
the right of these organizations to declare war. In point of fact, the United Nations
authorized a blockade in the Korean “police action” and claimed all of the usual
legal incidents of a blockade during a state of war. War, of course, was not
declared by the United Nations or by nations participating.

                III. Presidential Authority to Declare a Blockade

    Both practice and authority support the proposition that the President, in the
exercise of his constitutional power as Commander in Chief, can order a blockade
without prior congressional sanction and without a declaration of war by Congress.
President Lincoln took such action in 1861, and his authority was sustained by the
Supreme Court in the Prize Cases. 67 U.S. (2 Black) 635 (1862). While the
Supreme Court there found, in accordance with the doctrine discussed above, that
a state of war existed as a matter of fact and as a result of the proclamation by the
President of a blockade, the Court did not suggest that the President was remiss in
failing to seek a declaration of war from Congress.
    On April 20, 1898, a joint resolution of Congress directed the President to use
the land and naval forces of the United States to compel the Government of Spain
to relinquish its authority over Cuba. Pub. Res. No. 55-24, 30 Stat. 738. In accord-
ance with this resolution, President McKinley, on April 22, issued a proclamation
instituting a naval blockade of Cuba. 14 Compilation of the Messages and Papers
of the Presidents 6472 (James D. Richardson ed., 1909). Subsequently, Congress
declared that a state of war existed and that such state had existed since prior to the
proclamation. Pub. L. No. 55-189, 30 Stat. 364 (Apr. 25, 1898). But it is clear that
the President did not depend upon any congressional declaration of war, or even
upon a future ratification of his proclamation, when he issued it.
    Finally, President Truman, in 1950, issued an order blockading Korea. He
stated that he did so in keeping with the Security Council’s request for support, but
he did not then seek congressional authorization for the act, nor did he seek a
declaration of war. White House Statement Following a Meeting Between the
President and Top Congressional and Military Leaders to Review the Situation in
Korea, Pub. Papers of Pres. Harry S. Truman 513 (1950).



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   I believe with or without the congressional resolution of October 3, 1962, Pub.
L. No. 87-733, 76 Stat. 697, the President could declare a blockade of Cuba, and it
is doubtful if Congress could circumscribe this right. The instant resolution,
however, tends to support the proposed action, and thus serves a purpose analo-
gous to that of the 1898 Resolution and the 1950 action of the Security Council.
   It should be noted that even if one were to assume that international law re-
quires a state of war to exist before one can invoke the right of blockade, this
international rule is not pertinent to the President’s authority under the Constitu-
tion. There are numerous examples of American Presidents taking measures which
could internationally be regarded as acts of war without first seeking congressional
authority. And no foreign state could argue that a state of war did or did not exist
because American constitutional procedures were or were not followed in a
particular instance.

          IV. Unilaterally Declared Blockade Under the U.N. Charter

    The most difficult legal problem is to justify a unilateral declaration of block-
ade in the face of the U.N. Charter. The Charter appears to reserve to the United
Nations, or to regional organizations, most measures involving the use of force.
But, at the same time, it explicitly precludes the use of force only against the
“territorial integrity” or “political independence” of another state (Article 2), and
even this is qualified by recognizing the right of a state to act in self-defense
(under Article 51) against an armed attack. In addition, the Charter forbids other
actions which breach the peace or are inimical to the purposes of the United
Nations.
    Three justifications of a unilateral blockade are possible: (1) self-defense;
(2) that it is necessary to preserve the peace; and (3) that it is not forbidden by the
Charter.
    Self-defense is a difficult argument in view of the requirement for an “armed
attack.” Some writers, however, take the realistic view that a state need not wait so
long if, in fact, to do so would so jeopardize its security position as to render it
helpless.
    An easier argument, in my judgment, is to assert the right to preserve the peace
by acting in an emergency on behalf of a regional organization, promptly submit-
ting the matter to the organization for ratification. Acting without prior approval
could be justified on the basis of urgency and lack of time. In the case of U.S.
action against Cuba it could be further bolstered by prior findings of the organiza-
tion and the long history of U.S. protection of Latin America against threats of
foreign domination.
    This latter argument would be difficult to maintain if the United States were
actually to mount an assault on Cuba. But a blockade is not an action which is
irreversible if subsequently it fails of ratification, and is correspondingly more
defensible as a unilateral step.



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   The third argument in justification is closely related to the second. I believe one
could successfully contend that a state has the right unilaterally to prevent a
change in the status quo adverse to its security and itself a threat to the peace
pending action by the OAS (or United Nations), provided the action it takes is
essentially non-violent and designed to protect rather than irrevocably change the
pre-existing situation. This, of course, would be true of blockade. Thus, until the
OAS either supported or renounced the U.S. blockade, I believe we would be
justified in maintaining it as a measure preserving a pre-existing state of affairs
and preventing a situation which might require more drastic action to overturn or
even lead to full-scale war.

                        V. Blockade and Marine Insurance

   The effect of a blockade on marine insurance can be viewed from several
standpoints. First, from the standpoint of the blockading state it is illegal for
insurance companies to write insurance on cargoes destined to the ports of the
blockaded state. This would, of course, under the historic view be prohibited
trading with an enemy. On the other hand, it would not be illegal for an English
insurance company to write policies on cargoes destined to a blockade country
where England was not the blockading state. See 2 Joseph Arnould, Arnould on the
Law of Marine Insurance and Average § 760, at 681 (Robert S. Chorley ed., 14th
ed. 1954). As a practical matter, however, it is obvious that British companies will
not write policies on cargoes destined to Cuba because of the risk of loss involved.
   A second insurance problem relates to neutral ships on the high seas bound for
a blockaded port before the institution of the blockade or caught in such a port
with a cargo taken on before the blockade has been instituted. This situation
involves the application of the usual clause in marine insurance policies covering
loss arising from “arrests, restraints, and detainments of all kings, princes, and
people of what nation, condition, or quality whatsoever.” Under American law,
this clause protects a neutral vessel in the situation described. Olivera v. Union Ins.
Co., 16 U.S. (3 Wheat.) 183 (1818) (Marshall, C.J.); Vigers v. Ocean Ins. Co., 12
La. 362 (1838). Apparently this is also the law in continental European countries.
On the other hand, in England “it has been repeatedly decided, and must now be
taken as clear insurance law, that neither interdiction of trade at the port of
destination after risk commenced, nor interception of the voyage by blockade, or
by the imminent and palpable danger of capture or seizure, amounts to a risk for
which English underwriters are answerable under the common form of policy,
either as an ‘arrest, restraint, and detention,’ or in any other way whatever.”
2 Arnould, Marine Insurance § 804, at 727.




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