Validity of Congressional-Executive Agreements that Substan­
  tially Modify the United States’ Obligations Under An Exist­
  ing Treaty

It lies within Congress’s power to authorize the President to modify substantially the United States’
     domestic and international legal obligations under a prior treaty, including an arms control treaty,
     by making an executive agreement with our treaty partners, without Senate advice and consent.

                                                                                                    N o v e m b e r 2 5 , 1996


                                       M e m o r a n d u m O p in io n      for th e

                                S p e c ia l A s s is t a n t   to the   P r e s id e n t   and

                        L e g a l A d v is e r   to th e    N a t io n a l S e c u r it y C o u n c il


   Y o u have sought our views on the question whether Congress can authorize
the President to enter into an international agreement that substantially modifies
the obligations which the United States would otherwise have under a pre-existing
treaty, or whether only the Senate can do so, pursuant to the treaty-making power,
U.S. Const, art. II, §2, cl. 2.1 We conclude that it lies within the power of Con­
gress to authorize the President substantially to modify the United States’ obliga­
tions under a prior treaty, including an arms control treaty.
   A “ treaty” in the constitutional sense2 has two aspects: it may state a judicially
enforceable rule of domestic law; and it creates binding obligations between or
among the parties in international law. (See Part I below.) It is well established
that Congress has the power, by legislation, to modify the domestic legal effects,
if any, of a treaty. (See Part II below.) Insofar as the treaty embodies international
legal obligations, these may remain in force, even after an Act of Congress has
superseded the treaty as a matter of domestic law; but the States that are parties
to the treaty may consent to the modification of the obligations that the treaty
imposes. (See Part El below.) If Congress authorizes the President to enter into

    1The context in which you had originally raised this question was Congress’s consideration o f a proposed provision
o f the Department o f Defense Authorization Act for Fiscal Year 1997, purporting to prohibit the United States
from being bound by any international agreement that would substantively modify the Treaty on the Limitation
o f Anti-Ballistic Missile Systems, May 26, 1972, U nited States-U .S.S.R., T.I.A.S. 7503, 23 U.S.T. 3435, unless
that agreement was made pursuant to the President’s treaty-making power specified in Article II, Section 2, Clause
2 of the Constitution. W e had previously addressed another aspect o f that legislation. See Constitutionality o f Legisla­
tive Provision Regarding ABM Treaty, 

(1996).
   Our use o f the term authorize necessarily contemplates the grant o f authority prior to taking legally effective
action. We thus perceive no distinction between “ pre” -authorizalion and authorization in the present context.
   2 It is important to distinguish the constitutional sense o f the term “ treaty,” which is relevant here, from other
uses of the term in international or domestic law. “ The word 4treaty’ has more than one meaning. Under principles
o f international law, the word ordinarily refers to an international agreement concluded between two sovereigns,
regardless o f the manner in which the agreement is brought into force. Under the United States Constitution, o f
course, the word ‘treaty’ has a far more restrictive meaning. Article II, § 2 , cl. 2, o f that instrument provides that
the President ‘shall have Power, by and with the Advice and Consent o f the Senate, to make Treaties, provided
two thirds o f the Senators present concur.’ ” Weinberger v. Rossi, 

, 29-30 (1982) (citation and footnotes
omitted).


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                              Opinions o f the Office o f Legal Counsel in Volume 20


an executive agreement with our treaty partners to modify those obligations, and
those States consent to such modifications when the President proposes them, then
the treaty obligations can be modified by executive agreement, without Senate
advice and consent. (See Part IV below.)

                                                            I.

 At the outset, it is essential to recognize the dual nature of treaties, as instru­
ments of both domestic and international law. As the Supreme Court has said,

           [a] treaty is primarily a compact between independent nations. It
           depends for the enforcement of its provisions on the interest and
           the honor of the governments which are parties of it. If these fail,
           its infraction becomes the subject of international negotiations and
           reclamations, so far as the injured party chooses to seek redress,
           which may in the end be enforced by actual war. It is obvious that
           with all this the judicial courts have nothing to do and can give
           no redress. But a treaty may also contain provisions which confer
           certain rights upon the citizens or subjects of one of the nations
           residing in the territorial limits of the other, which partake of the
           nature of municipal law, and which are capable of enforcement as
           between private parties in the courts of the country.

H ead M oney Cases, 

, 598 (1884).3




    3 See also Foster v. Neilson, 27 U.S. (2 Pet.) 253, 314 (1829) (Marshall, C J .) ( “ A treaty is in its nature a contract
betw een tw o nations, not a legislative act. It does not generally effect, o f itself, the object to be accomplished,
especially so far as its operation is infra-territorial; but is carried into execution by the sovereign power of the
respective parties to the instrument. In the U nited States a different principle is established. Our constitution declares
a treaty to be the law o f the land. It is, consequently, to be regarded in courts of justice as equivalent to an act
o f the legislature, w henever it operates o f itself without the aid o f any legislative provision.” ); Taylor v. Morton,

, 785 (C.C.D. Mass. 1855) (N o. 13,799) (Curtis, Circuit Justice), affd, 67 U.S. (2 Black) 481 (1862)
(treaties are “ contracts, by which [sovereigns] agree to regulate their ow n conduct” and, under the Constitution,
“ part o f o ur municipal law ” ), Goldwater v. Carter, 

, 705 (D.C. Cir.), vacated, 

(1979)
( “ a treaty is sui generis. It is not just another law. It is an international com pact, a solemn obligation o f the United
States and a 'suprem e Law ’ that supersedes state policies and prior federal laws. For clarity o f analysis, it is thus
well to distinguish between treaty-making as an international act and the consequences which flow domestically
from such act. In one realm the Constitution has conferred the prim ary role upon the President; in the other, Congress
retains its prim ary role as lawmaker.” ); 1 W estel W oodbury W illoughby, The Constitutional Law o f the United
States §3 17a, at 577 (2d ed. 1929) ("T reaties entered into by the United States may be viewed in tw o lights:
(1) as constituting parts o f the supreme law o f the land, and (2) as compacts between the United States and foreign
Pow ers.” ).


                                                          390
      Validity o f Congressional-Executive Agreements that Substantially M odify the United States’
                                  Obligations Under An Existing Treaty

  A “ treaty,” therefore, has two aspects: insofar as it is self-executing, it pre­
scribes a rule of domestic or municipal law4 and, as a compact or contract be­
tween nations, it gives rise to binding obligations in international law.5

                                                         II.

   Under the Supremacy Clause of the Constitution, treaties, like Acts of Congress,
are made “ supreme Law,” U.S. Const, art. VI, cl. 2; Maiorano v. Baltim ore &
Ohio R.R. Co., 

, 272-73 (1909). Accordingly, “ treaty provisions,
which are self-executing in the sense that they require no additional legislation
to make them effective, are equivalent to and of like obligation with an act of
Congress.” 6 Further, insofar as a treaty incorporates a rule of domestic law, the
Supreme Court has long held that it may be modified or repealed by a later Act
of Congress.7 See H ead M oney 

(“ so far as a treaty made
by the United States with any foreign nation can become the subject of judicial
cognizance in the courts of this country, it is subject to such acts as congress
may pass for its enforcement, modification, or repeal” ); La Abra Silver Mining
Co. v. United States, 

, 460 (1899) (“ Congress by legislation, and
so far as the people and authorities of the United States are concerned, could
abrogate a treaty made between this country and another country which had been
negotiated by the President and approved by the Senate.” ); A lvarez y Sanchez
v. United States, 

, 175-76 (1910) (“ an act of Congress, passed after
a Treaty takes effect, must be respected and enforced, despite any previous or
existing Treaty provision on the same subject” ); United States v. Stuart, 

As C hief Justice M arshall pointed out in Foster v. 

, not all treaty provisions are self­
executing: they may require implementing legislation to be given their full effect. Many treaties are, however, self­
executing. For example, in United States v. The Schooner Peggy, 5 U.S. (1 Cranch) 103, 110 (1801) (M arshall,
C J.), the Court considered a treaty between the United States and France, ratified during the pendency of the appeal
o f the condemnation o f a seized French vessel, that required that vessels seized by either nation should be restored
if not yet definitively condemned. The Court held that the treaty controlled the disposition o f the prize: the treaty
was effective o f its ow n force, without need o f any further legislative action, and thus provided the rule of decision
on appeal, rather than a prior statute that would have authorized the vessel's condemnation. The Supreme Court
has given “ self-executing” effect to numerous treaties. See Disposition by Treaty o f Territory or Property Belonging
to the United States, 43 O p. A tt’y Gen. 96, 99, 103-04 & n.6 (1977) (Bell, A .G .) (citing cases), see also Samuel
B. Crandall, Treaties: Their Afaking and Enforcement §73, at 162-63 & n.16 (2d ed. 1916) (discussing distinction
between self-executing and non-self-executing treaties, and illustrating former category).
    s See The Vienna Convention on the Law o f Treaties, ait. 26 ( “ Every treaty in force is binding upon the parties
to it and must be perform ed by them in good faith.” ), reprinted in Basic Documents in International Law 388,
400 (Ian Brownlie ed., 4th ed. 1995). Although not ratified by the United States, this convention “ is frequently
cited . . . as a statement o f customary international law .” Review o f Domestic and International Legal Implications
o f Implementing the Agreement with Iran, 4A Op. O.L.C. 314, 321 (1981).
   6 Canadian Boundary Waters, 30 Op. A tt’y Gen. 351, 353 (1915) (citing Foster v. 

; The
Cherokee Tobacco, 78 U.S. ( I I Wall.) 616, 621 (1870); Chew Heong v. United States, 

, 539 (1884);
Head Money 

; and Whitney v. Robertson, 

, 194 (1888)). See also Cook v.
United States, 

, 118-19 (1933); Exemption o f Resident Aliens from Military Service Pursuant to Trea­
ties — Bar to Eligibility fo r Citizenship, 42 Op. Att’y Gen. 373, 379 (1968).
   ’ There was some earlier authority to the contrary. See Thompson's Case, 9 Op. A tt’y Gen. 1, 6 (1857) (Black,
A.G.) (“ Congress has no authority to abrogate a treaty made by the Executive, any more than the Executive has
to abrogate a law passed by Congress.” ).


                                                        391
                             Opinions o f the Office o f Legal Counsel in Volume 20


353, 375 (1989) (Scalia, J., concurring in judgment) (Congress “ may abrogate
or amend [a treaty] as a matter of internal law by simply enacting inconsistent
legislation.” ); Congressional Authority to M odify an Executive Agreement Settling
C laim s A gainst Iran, 4A 0p. O.L.C. 289 (1980).8
  The rationale for this rule was set forth in 1855 by Justice Curtis, sitting as
Circuit Justice. Justice Curtis wrote:

              The first and most obvious distinction between a treaty and an
           act of congress is, that the former is made by the president and
           ratified by two thirds of the senators present; the latter by majorities
           of both houses of congress and the president, or by the houses only,
           by constitutional majorities, if the president refuses his assent. Ordi­
           narily, it is certainly true, that the powers of enacting and repealing
           laws reside in the same persons. But there is no reason, in the na­
           ture of things, why it may not be otherwise. . . . I think it is impos­
           sible to maintain that, under our constitution, the president and sen­
           ate exclusively, possess the power to modify or repeal a law found
           in a treaty. If this were so, inasmuch as they can change or abrogate
           one treaty, only by making another inconsistent with the first, the
           government of the United States could not act at all, to that effect,
           without the consent of some foreign government; for no new treaty,
           affecting, in any manner, one already in existence, can be made
           without the concurrence of two parties, one of whom must be a
           foreign sovereign. That the constitution was designed to place our
           country in this helpless condition, is a supposition wholly inadmis­
           sible.

Taylor v. M 

.
  Accordingly, it lies within the power of Congress to modify the substantive
obligations that a treaty imposes upon the United States, or to authorize the Presi­
dent to modify those obligations, insofar as those treaty obligations are binding
as a matter of domestic or municipal law. The advice and consent of the Senate
are not necessary to achieve that outcome.




   8 Sim ilarly, a treaty can supersede a prior A ct o f Congress to the extent that the two are incompatible. See Charlton
v. Kelly , 229 U .S. 447, 463 (1913); United States v. Lee Yen Tai, 

, 220 (1902); Canadian Boundary
Waters, 30 Op. A tt’y Gen. at 352-53; Congressional Research Service, The Constitution o f the United States o f
America: Analysis and Interpretation, S. Doc. N o. 99-16, at 505 (1982); Samuel B. Crandall, Treaties: Their Making
and Enforcement §7 2 , at 161-62.

                                                          392
      V alidity o f C ongressional-E xecutive A greem ents that Substantially M o d ify the U nited States'
                                    O bligations Under A n Existing Treaty

                                                       III.

                                                        A.

  The unilateral modification or repeal of a provision of a treaty by Act of Con­
gress, although effective as a matter of domestic law, will not generally relieve
the United States of the international legal obligations that it may have under
that provision. See Pigeon R iver Improvement, Slide & Boom Co. v. Charles W.
Cox, Ltd., 

, 160 (1934) (while an Act of Congress that conflicted
with a treaty provision “ would control in our courts as the later expression of
our municipal law . . . the international obligation [would] remain[] unaffected” ).
Secretary of State Charles Evans Hughes (later the author, as Chief Justice, of
the Pigeon R iver opinion) explained the position well:

          a judicial determination that an act of Congress is to prevail over
          a treaty does not relieve the Government of the United States of
          the obligations established by a treaty. The distinction is often ig­
          nored between a rule of domestic law which is established by our
          legislative and judicial decisions and may be inconsistent with an
          existing Treaty, and the international obligation which a Treaty es­
          tablishes. When this obligation is not performed a claim will inevi­
          tably be made to which the existence of merely domestic legislation
          does not constitute a defense and, if the claim seems to be well
          founded and other methods of settlement have not been availed of,
          the usual recourse is arbitration in which international rules of ac­
          tion and obligations would be the subject of consideration.!9]

   “ [W]e are bound to observe [a treaty] with the most scrupulous good faith
. . . [0]ur Government could not violate [it], without disgrace.” The Amiable
Isabella, 

, 68 (1821). “ The foreign sovereign between whom and the
United States a treaty has been made, has a right to expect and require its stipula­
tions to be kept with scrupulous good faith . . . .” Taylor v. 

.10 “ A party may not invoke the provisions of its internal law as justification

  9 Letter for the Secretary o f the Treasury, from the Secretary o f State, Feb. 19, 1923, quoted in 5 Green Haywood
Hackworth, Digest o f International Law § 489, at 194-95 (1943).
  10C hief Justice (and form er President) Taft, sitting as sole arbitrator in an international dispute, stated that
    a treaty may repeal a statute, and a statute may repeal a treaty. The Supreme Court cannot under the
    Constitution recognize and enforce rights accruing to aliens under a treaty which Congress has repealed
    by statute. In an international tribunal, however, the unilateral repeal o f a treaty by a statute would not
    affect the rights arising under it and its judgment would necessarily give effect to the treaty and hold
    the statute repealing it o f no effect.
                                                                                                        Continued


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                             Opinions o f the Office o f Legal Counsel in Volume 20


for its failure to perform a treaty.” Vienna Convention on the Law of Treaties,
art. 27, reprinted in Basic Docum ents in International Law at 400.

                                                           B.

  As with contracts of other kinds, however, the parties to a treaty may agree
to modify the obligations to which the treaty gives rise. It is “ a general principle
of [international] law recognized by civilized nations” that “ [a]ny legal position,
or system of legal relationships, can be brought to an end by the consent of all
persons having legal rights and interests which might be affected by their termi­
nation.” International Status o f South-West Africa, 1950 I.C.J. 128, 167 (July 11)
(Separate Opinion of Judge Read). As a general rule of international law, there­
fore, “ [a] treaty may be amended by agreement between the parties.” Vienna
Convention on the Law of Treaties, art. 39, reprinted in Basic Documents in Inter­
national L aw at 404.11 The principle was well stated in a study prepared for the
Senate Foreign Relations Committee:

              The amendment of a binding international agreement may be ac­
           complished in a variety of ways including, among others, . . . by
           the consent of the parties . . . . Amendment or modification of
           an international agreement by consent of the parties is recognition
           of the fact that consent is the basis of international agreements.
           Accordingly, the parties are at liberty to change an international
           agreement regardless of its terms. For similar reasons, a later agree­
           ment on the same subject involving the same parties that expressly
           or impliedly modifies an earlier agreement will be regarded as ef­
           fecting the resulting change.

Treaties an d O ther International Agreements: The R ole o f the United States Sen­
ate, S. Rep. No. 53, 103d Cong., 1st Sess. 140 (Comm. Print 1993) (“ S. Rep.
53” ).12
 18 Am. J. In t’l L. 147, 159-60 (1924) (em phasis added). See also The Ship James and William, 

,
306 (1902) (decree o f French Government abrogating provisions o f treaty o f 1778 relating to contraband goods
on neutral vessels justified French courts in condem ning such vessels if seized by French cruisers, but did not abrogate
any treaty right o f the U nited States); Ropes v. Clinch, 

, 1174 (C.C.S.D.N.Y. 1871) (No. 12,041)
(Congress m ay “ legislate as if no such treaty existed, in modification or alteration o f what, by force o f the treaty,
has been the law heretofore, thus modifying the law o f the land, without denying the existence o f the treaty, or
the obligations thereof betw een the two governments, as a contract, and answ er therefor to such foreign government,
or meet its reclam ation o r retaliation as may b e necessary.” ); I Westel W oodbury W illoughby, The Constitutional
Law o f the United States § 3 2 4 , at 585 (“ T h e termination o f a treaty as an international compact carries with it
the annulm ent o f the agreem ent as a law o f th e land, but its annulment as a law by Congress does not cany with
it its annulment as an international compact.” ).
    11 This C onvention details in arts. 40 and 41 more specific rules for the amendment (as among all the parties)
and modification (as among certain o f the parties) o f a multilateral treaty.
    12 See also David A. Koplow, When Is An Amendment Not An Amendment? Modification O f Arms Control Agree­
ments Without The Senate, 59 U. Chi. L. Rev. 981, 1023 (1992) ( “ International law imposes few limitations upon
parties’ abilities to change th eir treaty obligations. In general, states are free to alter their commitments to any


                                                          394
      Validity o f Congressional-Executive Agreements that Substantially M odify the United States'
                                  Obligations Under An Existing Treaty

   The United States has often modified its treaty rights and obligations through
agreements with its treaty partners: “ following a precedent established in 1784
when the Treaty of Commerce and Amity with France was modified by an ex­
change of notes between the French Foreign Minister and Benjamin Franklin, ex­
ecutive agreements have not infrequently been utilized as a method of altering
treaties.” 13 Thus, assuming that the consent of our treaty partners was obtained,
the United States could, as a matter of international law, substantially modify
its pre-existing treaty obligations by agreement with its treaty partners.
   The only remaining question, therefore, is whether, as a matter of constitutional
law, the President has the power to modify, by means of an executive agreement
authorized by Act of Congress, the international legal obligations that the United
States has under a treaty, or whether the only constitutional method by which
the President may achieve that end is through the advice and consent of the Senate.
We discuss that question in the following section.

                                                         IV.

                                                         A.

   “ When the President acts pursuant to an express or implied authorization of
Congress, his authority is at its maximum, for it includes all that he possesses
in his own right plus all that Congress can delegate.” Youngstown Sheet & Tube
Co. v. Sawyer, 

, 635 (1952) (Jackson, J., concurring). The Supreme
Court has repeatedly emphasized the sweeping authority of the President in the
field of foreign affairs, particularly when his own considerable inherent powers
in that area are augmented by those of Congress. See, e.g., Dam es & M oore v.
Regan, 

, 674 (1981); Chicago & Southern A ir Lines, Inc. v. W ater­
man S.S. Corp., 

, 109-10 (1948); H irabayashi v. United States, 

, 92-93 (1943); United States v. Curtiss-W right Export Corp., 

(1936). We believe that the inherent powers of the President over foreign
affairs, coupled with whatever powers Congress can and does delegate to him
in this area, are constitutionally sufficient to enable the President to make an exec­
utive agreement that substantially modifies the international legal obligations of
the United States under a prior treaty.14
extent, at any time, and in any manner, provided that they are reasonably clear about what they are doing and
that they reciprocally agree or at least acquiesce in the outcom e.").
   13 Myres S. McDougal & A sher Lans, Treaties and Congressional-Executive or Presidential Agreements: Inter­
changeable Instruments o f National Policy, 5 4 Yale L.J. 181, 334 (1945) (footnote omitted).
   14 We do not consider here how far the President has the authority, acting without either Senate advice and consent
or an Act of Congress, substantially to modify the United States’ obligations under treaty or international law. We
note, however, that the executive branch has taken the position that the President possesses the authority to terminate
a treaty in accordance with its terms by his unilateral action, and a plurality o f the Supreme Court concluded that
the issue was a non-justiciable political question. See Goldwater v. 

(plurality op.). See
generally Memorandum for the Attorney General, from Theodore B. Olson, Assistant Attorney G eneral, Office of
                                                                                                             Continued


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                              Opinions o f the Office o f Legal Counsel in Volume 20


  The Constitution makes the President the Nation’s “ guiding organ in the con­
duct of our foreign affairs . . . . He . . . was entrusted with . . . vast powers
in relation to the outside world . . .      Ludecke v. Watkins, 33

60, 173
(1948).15 Pursuant to his inherent powers, the President has made executive agree­
ments with other countries, not submitted to the Senate for its advice and consent
or to Congress for its approval, including agreements that regulated the use of
military forces.16 Congress to o — as distinct from the Senate under its treaty-mak-
ing power— has some power to vary the international legal obligations of the
United States.17 So, for example, in W einberger v. 

, the
Legal Counsel, Re: Presidential Authority to Modify the Conditions under which the United States Will Recognize
the Compulsory Jurisdiction o f the International Court o f Justice Without Prior Congressional Approval at 1 (Apr.
9, 1984) ( “ although the question has never been definitively resolved by the courts, a substantial body of judicial,
historical, and scholarly support exists for th e proposition that, under certain circumstances, the President is constitu­
tionally em pow ered unilaterally to terminate an existing treaty in accordance with its term s"). But see International
Load Line Convention, 40 Op. A tt’y Gen. 119, 123 (1941) (opining that President had power to suspend a treaty,
 but suggesting that “ action by the Senate o r by the C ongress" would be “ required" to “ denounce" or “ otherwise
 abrogate! ] ’’ it).
    A ssum ing that the President does have th e power unilaterally to terminate a treaty, it appears to follow that he
also has the authority to relieve the United States o f the affirmative obligations imposed on it by particular treaty
provisions. It would not follow, however, th at he had the authority unilaterally to augment the United States’ treaty
obligations. Moreover, it has been held that th e President has no constitutional power to abrogate rights under Indian
treaties. See Mille Lacs Band o f Chippewa Indians v. State o f Minnesota, 

, 823-24 (D. Minn.
 1994), appeal dismissed, 

(8th C ir. 1995).
    13 The President’s authority in the field o f foreign affairs flows, in large part, from the President’s position as
C hief Executive, U.S. Const, art. II, §1, cl. 1, and as Com m ander in Chief, 

§2 , cl. 1. It also derives
from his more specific powers to “ make T rea tie s" with the advice and consent of two-thirds o f the Senators present,

§ 2 , cl. 2; to “ appoint Ambassadors . . . and C onsuls," id:, and to “ receive Ambassadors and other
public M inisters," 

§ 3 . The Supreme Court has repeatedly recognized the President’s authority with respect
to the conduct o f foreign affairs. See, e.g.. Department o f Navy v. Egan, 

, 529 (1988) (the Supreme
Court has “ recognized ‘the generally accepted view that foreign policy was the province and responsibility of the
E xecutive’ ’’) (quoting Haig v. Agee, 453 U .S . 280, 2 9 3 -9 4 (1981)); Alfred Dunhill o f London, Inc. v. Republic
o f Cuba, 

, 70 5 -0 6 n.18 (1976) ( “ [T]he conduct o f [foreign policy] is committed primarily to the Execu­
tive Branch . . . ." ); United States v. Louisiana, 

, 35 (I960) (the President is “ the constitutional represent­
ative o f the United States in its dealings with foreign nations").
    16The President’s “ inherent pow ers" as Com m ander in C hief are “ clearly extensive." Loving v. United States,

, 776 (1996) (Scalia, J., concurring in part and in the judgment). The executive agreements that past
Presidents have concluded under the Com m ander in C hief authority have often been “ important com pacts," such
as the armistice, or peace protocol, with Spain, o f A ugust 12, 1898, establishing the basis o f the conditions for
ending the Spanish-American W ar. 2 Charles Cheney Hyde, International Law Chiefly As Interpreted and Applied
by the United States §508, at 1411 (2d rev. ed. 1945). See also 5 John Bassett Moore, A Digest o f International
Law 213(1906).
    17 That proposition might be questioned. See, e.g., 1 W estel W oodbury Willoughby, The Constitutional Law o f
the United Stales §324, at 585 ( “ it seems almost too clear for argument that Congress, not having been made
by the C onstitution a participant in the treaty-making pow er, has no constitutional authority to exercise that pow er
either affirmatively or negatively, that is, by creating or destroying international agreem ents").
    W e believe that Congress does possess delegable authority in this area. First, among the powers vested in Congress
by the Constitution is the pow er o f declaring w ar. U.S. Const, art. 1, §8, cl. 11. A declaration of war is a legislative
act that can have the effect o f abrogating a treaty in whole o r in part. See Karnuth v. United States, 

, 239-41 (1929) (Declaration o f War o f 1812 abrogated provision o f Treaty of 1794 granting British subjects
right freely to enter United States); see also Valk v. United States, 

, 67 (1894), ( “ war supersedes
treaties o f peace and friendship"), affd, 

(1897); cf. Argento v. Horn, 

, 260-62 (6th
C ir.) (Potter Stewart, J.) (extradition treaty w ith Italy was suspended but not abrogated by war), cert, denied, 

(1957). W hen Congress acts under its war power, “ a wide latitude o f discretion must be accorded" to
it, for on that pow er “ the very life of the nation depends." Hamilton v. Kentucky Distillers & Warehouse Co.,

, 163 (1919) (Brandeis, J.); see also Dryfoos v. Edwards, 

, 599 (S.D.N.Y. 1919) (L. Hand,
J.) (C ongress’ w ar pow er may “ be inferred [not only from specific clauses of article I, but also] from the fact
that the United States is the only sovereign recognized among the world o f nations, within the territory of the


                                                           396
      Validity o f Congressional-Executive Agreements that Substantially Modify the United States'
                                  Obligations Under A n Existing Treaty

Supreme Court implied that Congress, if it expressed its intent with sufficient
clarity, could effect the abrogation of the United States’ international obligations,
as set forth in international agreements for the hiring of local nationals at the
United States’ overseas military bases.18 It can reasonably be maintained that,
if Congress may effect the abrogation of international obligations, it has some
power to authorize the President to modify them.

                                                         B.

  The practice of the two branches discloses many examples of binding agree­
ments that Presidents have made with foreign States, relying on the inherent au­
thority of the Executive, as affirmed and amplified by Congress. As the Senate
Foreign Relations Committee study cited above points out,

             Congressional authorization for the conclusion of international
          agreements dates from the earliest days of the Nation’s constitu­
          tional history. Thus, in 1790 Congress empowered the President
          to pay off the Revolutionary War debt by borrowing money from
          foreign countries “ upon terms advantageous to the United States”
          and to conclude “ such other contracts respecting the said debt as
          shall be found for the interest of the said States.” Two years later

United States, at once responsible and vested with any o f the powers which are customarily exercised by such
a sovereign so charged” ), a ffd sub nom., Hamilton v. Kentucky Distilleries & Warehouse Co., 

(1919).
Accordingly, it is at least arguable that Congress’ war power enables it to enact legislation, other than a formal
declaration o f war, that authorizes the President to vary the United States* obligations under disarmament or other
political-military treaties. Accord Armen R. Vaitian, Approval o f SALT Agreements by Joint Resolution o f Congress,
21 Harv. J. Int’l L. 421, 441 (1980) (“ it is clear that the power o f Congress to legislate with regard to arm s control
matters is nearly unlimited, and, when combined with the President's authority as Commander in Chief, is plenary” )
(footnotes omitted).
    Furthermore, Congress has been held to have the power to make peace by legislation, as an alternative to a
treaty. See Ludecke v. 

. Indeed, because o f the Senate’s refusal to ratify the Treaty of
Versailles, Congress by joint resolution authorized the President to terminate the war with Germany, see 42 Stat.
 105 (1921). The validity o f Congress’ action was recognized by both the Supreme Court, see Commercial Trust
Co. v. Miller, 

, 57 (1923), and by the Executive, see Proclamation o f Peace by the President, Aug.
25, 1921, 42 Stat. 1939, 1944. Again, it may be inferred that if Congress may make peace, it may authorize Executive
agreements, such as arms control measures, that conduce to peace.
    Finally, the Constitution vests in Congress the power to “ provide for the common Defence . . . of the United
States.” U.S. Const, art. I, § 8 , cl. 1. The Supreme Court has indicated that this clause enables Congress to authorize
the President to make agreements with foreign States that were directly related to the N ation’s defense. In People
o f the State o f New York ex rel. Rogers v. Graves, 

(1937), the Court reviewed a large body of legislation
dealing with the Panama Canal. These statutes included the Act o f June 28, 1902, ch. 1302, 32 Stat. 481, which
authorized the President to enter into an agreement to acquire control o f a strip o f land— the Panam a Canal Z one—
 from the Republic o f Colombia. To enact this mass o f legislation, the Court said, lay “ within the constitutional
power of Congress to provide for the national 

. Arguably, therefore, the “ common
Defence” clause also confers on Congress delegable power to authorize the President to enter into executive agree-
ments that modify our obligations under prior arms control treaties.
    19 See also Van Der Weyde v. Ocean Transp. Co., 

, 118 (1936) (Act of Congress requesting and
directing President to give notice to treaty partners o f termination o f treaties inconsistent with domestic legislation
made it “ incumbent upon the P resid en t. . . to reach a conclusion as to the inconsistency” between treaty provisions
and domestic statute, and “ [h]aving determined that [treaty provisions'] termination was necessary, the Preside
through the Secretary o f State took appropriate steps to effect it.” ).


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          the Postmaster General was authorized to make arrangements with
          the postmasters in any foreign country for the reciprocal receipt
          and delivery of letters and packets, through the post-offices. . . .
          Over the years, Congress has authorized or sanctioned additional
          agreements concerning a wide variety of subjects including inter
          alia, the protection of intellectual property rights, acquisition of ter­
          ritory, national participation in various international organizations,
          foreign trade, foreign military assistance, foreign economic assist­
          ance, atomic energy cooperation, and international fishery rights.

S. Rep. 53, at 52-53 (footnotes omitted). See also Seizure o f Foreign Ships on
the High Seas Pursuant to Special Arrangements, 4B Op. O.L.C. 406, 407 (1980)
(“ The President has Congress’ express authority to enter into special arrangements
[with foreign countries], including those that will aid the United States’ effort
to curtail drug traffic.” ); Validity o f Comm ercial Aviation Agreement, 40 Op. Att’y
Gen. 451, 452 (1946) (Clark, A.G.) (“ It is recognized that there are many classes
of agreements with foreign countries which are not required to be formulated as
treaties . . . [including] that class of executive agreements which are entered into
in accordance with, and within the scope of, authority vested in the executive
branch by legislation enacted by the Congress. Notable examples of agreements
which fall within this class are postal conventions and reciprocal trade agree­
ments.” ); P ostal Conventions with Foreign Countries, 19 Op. Att’y Gen. 513,
520 (1890) (Taft, S.G.) (beginning with legislation of 1792, the Postmaster Gen­
eral, by virtue of Congressional authorization, “ has exercised the treaty-making
power of the Government in so far as it was necessary to the improvement of
the foreign mail service,” without obtaining the advice and consent of the Senate
to such postal conventions). Cf. Antoine v. Washington, 

, 204 (1975)
(Court has repeatedly treated Executive agreements with Indian tribes ratified by
later Acts of Congress as “ law, and like treaties, the supreme law of the land” ).19
   The constitutionality of such “ Congressional-Executive agreements” is firmly
established. A cco rd S. Rep. 53, at 58.20 The Supreme Court long ago rejected
arguments that such agreements constitute an invalid delegation of power to the
President or the House of Representatives, or an improper invasion of the Senate’s
treaty-making power. See J.W. Hampton, Jr. & Co. v. United States, 

, 410-11 (1928); Field v. Clark, 

, 694 (1892); see also Whether
U ruguay Round Agreements R equired Ratification as a Treaty, 

A m ong earlier international agreements w hich were accomplished by Congressional-Executive agreements rather
than by Article II treaties were the annexation o f Texas, see Tejcas v. White, 74 U.S. (7 Wall.) 700 (1868) and
o f Hawaii, see Hawaii v. Mankichi, 

(1903). For discussion of the background o f these two annexations,
see Legal Issues Raised by Proposed Presidential Proclamation To Extend the Territorial Sea, 

,
25 1 -5 2 (1988); Louis Fisher, Constitutional Conflicts between Congress and the President 227-28 (3d rev. ed. 1991).
   20 But see Laurence H. Tribe, Taking Text and Structure Seriously: Reflections on Free-Form Method in Constitu­
tional Interpretation, 108 Harv. L. Rev. 1221, 1249-78 (1995) (defending exclusivity of Treaty Clause).

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      Validity o f Congressional-Executive Agreements that Substantially Modify the United States’
                                  Obligations Under An Existing Treaty

232, 234 (1994).21 An international agreement negotiated by the President and
concluded with prior, or subsequent, authorization from Congress has “ the force
and effect of an act of Congress.” 

, 229 (1978).

                                                           C.

   Of particular relevance here, the practice of the political branches underscores
that the President has the authority to make Congressional-Executive agreements
with our treaty partners that substantially modify the United States’ rights or obli­
gations under those treaties.
   Congress has enacted legislation in the political-military field that permits the
modification of the United States’ international obligations through a Congres­
sional-Executive agreement as an alternative to the treaty-making process. The
Arms Control and Disarmament Act of 1961, Pub. L. No. 87-297, §33, 75 Stat.
634, as recently amended by Pub. L. No. 103-236, §709, 108 Stat. 382, 494
(1994) (codified in relevant part at 22 U.S.C. § 2573(b)), provides that no action
obligating the United States to reduce or limit its Armed Forces or armaments
“ in a militarily significant manner” can be taken “ except pursuant to the treaty-
making power of the President set forth in Article II, Section 2, Clause 2 of the
Constitution o r unless authorized by the enactment o f further affirmative legisla­
tion by the Congress o f the United States’ ’ (emphasis added).22
   Further, in a 1990 study, the Congressional Research Service identified three
Congressional-Executive agreements since 1970 of a political-military nature; each
of them could arguably have been adopted as a treaty instead. These were the
Interim Agreement on the Limitation of Stategic Offensive Arms (“ Salt I ” ),
signed May 26, 1972, entered into force October 3, 1972, T.I.A.S. No. 7504, 23
U.S.T. 3462, which President Nixon submitted to Congress for its approval by
joint resolution, and which Congress authorized in Pub. L. No. 92-448, 86 Stat.

   21 “ Notwithstanding that the text o f the Constitution confers no explicit authority for the making o f congressional-
executive agreements, such agreements have been authorized frequently by Congress over the years on a wide variety
o f subjects. Similarly, the courts have been little troubled by theoretical considerations and have sustained such
agreements largely on the basis o f the actual practice o f the political branches o f the government and the cumulative
weight o f prior judicial decisions. Presumably, if a doctrinal basis were at this date necessary to uphold agreements
o f this type, the combined foreign affairs powers o f the Congress and the President would prove sufficient.” S.
Rep. 53, at 58-59.
   22 The legislative history o f section 33 o f the Arms Control and Disarmament Act indicates that neither the Senate
nor the House o f Representatives regarded the provision as infringing on the Senate's treaty-making power. See
Armen R. Vartian, Approval o f SALT Agreements by Joint Resolution o f Congress, 21 Harv. J. Int’l L. at 44 6 -
47 & n.95.
   The Senate had previously recognized that international political-military obligations could be undertaken by Act
of Congress rather than by treaty when, in 1943, it adopted the Connally Resolution. That resolution provided that
the United States, “ acting through its constitutional processes.” could join in an international authority w ith the
power to prevent aggression. The resolution's reference to “ constitutional processes” was understood to mean "th a t
international commitments (in this case joining the United Nations) could be made either by treaty or by a majority
of each House voting on a bill o r joint resolution.” Louis Fisher, Presidential War Power 7 4 (1995); see also
89 Cong. Rec. 8662 (1943) (explanation o f terms used in resolution).


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 746, signed September 30, 1972 23; a pair of identical agreements made by Presi­
dent Ford in 1975 with Egypt and Israel, under which the United States undertook
 to participate in an early-warning system in the Sinai, which Congress approved
 in Pub. L. No. 94-110, 89 Stat. 572, signed October 13, 1975, and which entered
into force on the same date, T.I.A.S. No. 8155, 26 U.S.T. 2271 (Israel), T.I.A.S.
No. 8156, 26 U.S.T. 2278 (Egypt); and a protocol signed by the United States,
Egypt and Israel on August 3, 1981, T.I.A.S. No. 10556, 34 U.S.T. 3341, entered
into force August 3, 1981, and T.I.A.S. No. 10557, 34 U.S.T. 3349, entered into
force March 26, 1982, outlining United States participation in a Multinational
Force and Observers unit, to function as a peacekeeping force in Sinai, for which
President Reagan requested and obtained Congressional authorization in Pub. L.
No. 97-132, 95 Stat. 1693, signed December 29, 1981. See Ellen C. Collier &
James V. Satumo, Congressional Research Service, Executive Agreements Sub­
m itted to Congress: Legislative Procedures U sed Since 1970 (Nov. 26, 1990).24
   Congress has also ratified, by legislation, Executive acts that substantially modi­
fied pre-existing treaty (or other international) obligations. Under article 3 of the
Treaty of Peace with Japan, Sept. 8, 1951, T.I.A.S. No. 2490, 3 U.S.T. 3169,
3172-73, Japan was required to concur in any proposal that the United States
made to the United Nations for placing certain islands under trusteeship. By a
1953 executive agreement, T.I.A.S. No. 2895, 4 U.S.T. 2912, President Eisen­
hower agreed to relinquish to Japan the United States’ rights under the Treaty
of Peace with respect to the Amami Islands. Although it appears that no prior
legislative authorization for this modification of the treaty existed, Congress in
1960 impliedly ratified the President’s action in Pub. L. No. 86-629, 74 Stat.
461, an Act, “ To provide for the promotion of economic and social development
in the Ryukyu Islands.” 25
   Finally, in its Resolution of Advice and Consent of 27 May 1988 to the U.S.-
U.S.S.R. Treaty on the Elimination of Their Intermediate-Range and Shorter-
Range Missiles (INF Treaty), the Senate adopted the “ Biden condition,” which
   23 “ [T]he Interim Agreement o f 1972 was by no means the fust non-treaty agreement pertaining to arms limitation
o r national security. In addition to numerous armistice agreements, the Rush-Bagot Agreement o f 1817, 8 Stat.
231, T.S. No. 110 1/2 (1846), the ‘Hot Line’ Agreement o f 1963, 1 U.S.T. 825, T.I.A.S. No. 5362, and unwritten
agreem ents with the Soviet U nion concerning moratoriums on nuclear testing (1958-1961) and placing nuclear weap­
ons in orbit (1963-1967), am ong others, w ere effected without Senate approval.” Armen R. Vartian, Approval o f
SALT Agreements by Joint Resolution of Congress, 21 Harv. J. In t’l L. at 442 n.77.
   24 In light o f such judicial and historical precedents, the Genera] Counsel to the Clerk o f the House o f Representa­
tives concluded that “ the U nited States m ay appropriately choose to negotiate an arms accord in the form o f a
Congressional-Executive agreem ent, and approve it by legislation, as an alternative to treaty ratification.” Memo­
randum for the Honorable D ante B. Fascell, Chairman, House Committee on Foreign A ffairs, from Steven R. Ross,
General Counsel to the Clerk, and Charles T iefer, Deputy General Counsel to the Clerk, Re: Congressional Approval
o f an Arms Control Agreement by Legislation Rather than Treaty Ratification (May 23, 1985), reprinted in 134
Cong. Rec. 7323 (1988). See also Memorandum for Ambassador Kampelman, Counselor, from Michael J. Matheson,
D eputy Legal A dviser, Re: Form o f submission o f arms control agreements (Apr. 14, 1988), reprinted in 134 Cong.
Rec. at 7324 ( “ N either the [Arm s Control an d Disarmament Act] nor the Constitution dictates which o f these two
options the President should exercise with respect to a particular [arms control] agreement,” but noting that “ [w]ith
one exception, the significant arm s control agreements o f the past few decades have all been submitted for the
advice and consent o f the Senate as treaties.” ).
   23 See 14 Marjorie M. W hiteman, Digest o f International Law § 23, at 230 (1970).


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    Validity o f Congressional-Executive Agreements that Substantially Modify the United Stales'
                                Obligations Under An Existing Treaty

provides that “ the United States shall interpret the Treaty in accordance with the
common understanding of the Treaty shared by the President and the Senate at
the time the Senate gave its advice and consent to ratification,” and that “ the
United States shall not agree to or adopt an interpretation different from that com­
mon understanding except pursuant to Senate advice and consent to a subsequent
treaty or protocol, o r the enactment o f a statute .” 134 Cong. Rec. 12,849 (1988)
(emphasis added). The Senate affirmed “ the applicability to all treaties of the
constitutionally-based principles” in this condition. Resolution of Advice and
Consent of 25 November 1991 to the Treaty on Conventional Armed Forces in
Europe (CFE Treaty), 137 Cong. Rec. 34,347, 34,348 (1991), adopted 

Because the Senate took the view that such “ common understandings”
of a treaty had the same binding effect as express provisions of the treaty for
purposes of U.S. law, the Biden condition logically supports the proposition that
the President may be authorized to accept changes in treaty obligations either by
further Senate advice and consent o r by statutory enactment.
   In light of these judicial and historical precedents, we conclude that Congress
may authorize the President, through an executive agreement, substantially to
modify the United States’ international obligations under an arms control (or other
political-military) treaty.

                                          Conclusion

  It lies within the power of Congress to authorize the President substantially
to modify the United States’ domestic and international legal obligations under
a prior treaty, including an arms control treaty.

                                                         CHRISTOPHER SCHROEDER
                                                        Acting Assistant A ttorney General
                                                             Office o f Legal Counsel




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