Relevance of Senate Ratification History

to Treaty Interpretation

T he m ost relevant extrinsic evidence o f a treaty’s m eaning are exchanges betw een the parties 

n egotiating it, i.e., the President a n d the foreign pow er. The portions o f the ratification record 

en titled to the greatest weight a re representations o f the Executive, w ho is in essence the 

draftsm an o f the treaty. The S e n a te ’s advice and consent function w as designed by the 

F ram ers as a check on the P resident’s treaty-m aking pow er, and the S enate’s deliberations 

cannot be ignored altogether. N onetheless, in all but the m ost unusual cases, the ratification 

record is not the determ inative so u rce o f evidence as to the treaty ’s m eaning under dom estic 

law .

April 9, 1987

M e m o r a n d u m O p in io n f o r t h e L e g a l A d v i s e r ,

D e p a r t m e n t o f S t a t e

I. Introduction and Summary

This memorandum responds to your request for the views of this Office 

concerning the relevance of the Senate’s deliberations on ratification of a treaty 

to subsequent interpretations of ambiguous treaty language by the Executive 

Branch. We use the term “deliberations” or “ratification record” to encompass 

sources such as hearings, committee reports, and floor debates, which are 

generally analogous to the “legislative history” of domestic statutes. Our focus 

is on the relevance of those sources to interpretation of a treaty as domestic law, 

i.e., their relevance to the President’s constitutional responsibility to “take Care 

that the Laws be faithfully executed.” U.S. Const, art. II, § 3.1 We understand 

that you are reviewing separately the relevance that would be ascribed under 

international law to the Senate’s ratification record.

The question you raise does not lend itself to any clear or easy answer. As 

discussed below, the dual nature of treaties as international agreements and as 

domestic law and the concomitant division of the treaty-making power between the President and the Senate create an inevitable tension. Primarily, 

treaties are international obligations, negotiated by the President in his capacity 

as the “sole organ of the federal government in the field of international 

relations,” United States v. Curtiss-Wright Export Corp., 299 U.S. 304, 320

1 It is indisputable that treaties are among the “supreme Law[s] of the Land,” U.S. Const, art. VI, cl. 2, and 

that the President’s constitutional duty under Article II extends to treaties as well as to statutes and the 

Constitution itself. See I Op. Att’y Gen. 566, 570 (1822); In re Neagley 135 U.S. 1, 64 (1890).

28
(1936). The most relevant evidence of the meaning of a treaty lies in the mutual 

exchange of views between the negotiating parties — an exchange in which the 

Senate does not formally participate unless it explicitly conditions its consent 

to a treaty and that condition is communicated to and accepted by the other 

party. Because the advice and consent function of the Senate, however, was 

designed by the Framers as a constitutional check on the President’s otherwise 

broad authority to make treaties that have the force of law, we believe that the 

deliberative record that is created when the Senate advises and consents to a 

treaty cannot be ignored in the'interpretative process. Nonetheless, in all but 

the most unusual case, the ratification record would not be the determinative — 

or even the primary — source of evidence as to the treaty’s meaning under 

domestic law.

In determining the weight to be assigned to that record, it should be observed 

that, conceptually, the constitutional division of treaty-making responsibility is 

essentially the reverse of the division of law-making authority. Congress 

initially agrees upon and enacts the language of domestic legislation, while the 

President reserves the right to determine whether that legislation will go into 

effect (subject, of course, to the override of any veto). Treaties, however, are 

proposed and negotiated by the President, subject to the approval or disapproval of the Senate. Given this conceptual framework, it is clear that the 

portions of the treaty ratification record that should be accorded more weight as 

to the treaty’s meaning are the representations of the executive — the draftsman, in effect, of the treaty. Statements by individual Senators, or even groups 

of Senators, are certainly entitled to no more consideration — and perhaps less

— than the limited weight such statements are given in the interpretation of 

domestic legislation when they are not confirmed by the legislation’s sponsor 

in colloquy or otherwise.

n . Constitutional Division of Treaty Authority

The powers of the national government were deliberately divided by the 

Framers among the three coordinate branches, because they considered the 

concentration of governmental power to be the greatest threat to individual 

liberty. “Basic to the constitutional structure established by the Framers was 

their recognition that ‘[t]he accumulation of all powers, legislative, executive, 

and judiciary, in the same hands . .. may justly be pronounced the very 

definition of tyranny.’” Northern Pipeline Co. v. Marathon Pipe Line Co., 458 

U.S. 50, 57 (1982) (quoting The Federalist No. 47, at 300 (J. Madison) (H. 

Lodge ed. 1888)). Accordingly, “[t]he Constitution sought to divide the delegated powers of the new Federal Government into three defined categories, 

Legislative, Executive, and Judicial, to assure, as nearly as possible, that each 

branch of government would confine itself to its assigned responsibility.” INS

v. Chadha, 462 U.S. 919, 951 (1983); see also Buckley v. Valeo, 424 U.S. 1, 

122 (1976). The Supreme Court has long acknowledged that the partitions 

separating each branch of government from the others must be maintained

29
inviolable if liberty is to be preserved. “The hydraulic pressure inherent within 

each of the separate Branches to exceed the outer limits of its power, even to 

accomplish desirable objectives, must be resisted.” INS v. Chadha, 462 U.S. at 951.

Under this separation of powers, the President has a dual role with respect to 

treaties. First, the President is responsible for “making” treaties, i.e., entering 

into negotiations with foreign governments and reaching agreement on specific 

provisions. U.S. Const, art. II, § 2, cl. 2. Second, as part of his responsibility to 

“take Care that the Laws be faithfully executed,”2 and as the “sole organ of the 

federal government in the field of international relations,”3 the President is 

responsible for enforcing and executing international agreements, a responsibility that necessarily “involve[s] also the obligation and authority to interpret 

what the treaty requires.” L. Henkin, Foreign Affairs and the Constitution 167

(1972) (Henkin); see also Collins v. Weinberger, 707 F.2d 1518, 1522 (D.C. 

Cir. 1983); American Law Institute, Restatement o f the Law, Foreign Relations

Law o f the United States (Second), §§ 149,150(1965) (Restatement (Second));

accord American Law Institute, Restatement o f the Law, Foreign Relations

Law o f the United States (Revised) (Tentative Final Draft, July 15, 1985) § 326 

(Restatement (Revised)).4

The President’s authority to make treaties is shared with the Senate, which 

must consent by a two-thirds vote.5 This “JOINT AGENCY of the Chief 

Magistrate of the Union, and of two-thirds of the members of [the Senate]”6 

reflects the Framers’ recognition that the negotiation and acceptance of treaties 

incorporates both legislative and executive responsibilities:

[T]he particular nature of the power of making treaties indicates 

a peculiar propriety in that union. Though several writers on the 

subject of government place that power in the class of executive 

authorities, yet this is evidently an arbitrary disposition; for if 

we attend carefully to its operation it will be found to partake 

more of the legislative than of the executive character, though it 

does not seem strictly to fall within the definition of either of 

them. The essence of the legislative authority is to enact laws, 

or, in other words, to prescribe rules for the regulation of the 

society; while the execution of the laws and the employment of 

the common strength, either for this purpose or for the common 

defense, seem to comprise all the functions of the executive

2 U.S. Const, art. II, § 3.

3 United States v. Curtiss-Wright Export Corp , 299 U.S. at 320; see also Haig v. Agee, 453 U.S. 280, 291 - 

292 (1981); Chicago & Southern Air Lines v. Waterman S.S. Corp., 333 U.S. 103, 190 (1948).

4 The President’s interpretation of a treaty is, of course, subject to review by the courts in a case or 

controversy that meets Article III requirements. See U.S. Const, art. Ill, § 2 (“The judicial Power shall extend 

to all C a s e s ,. . . arising under this Constitution, the Laws o f the United States, and Treaties made, or which 

shall be made, under their Authority"); see also Kolovrat v. Oregon, 366 U. S 187, 194 (1961); Factor v. 

Laubenheimer, 290 U.S. 276, 294 (1933); Jones v. Meehan, 175 U.S. 1, 32 (1899).

5 “[The President] shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, 

provided two thirds o f the Senators present concur. . . U.S. Const, art. II, § 2, cl. 2.

6 The Federalist No. 66, at 406 (A. Ham ilton) (C. Rossiter ed. 1961).

30
magistrate. The power of making treaties is, plainly, neither the 

one nor the other .... The qualities elsewhere detailed as indispensable in the management of foreign negotiations point out 

the executive as the most fit agent in those transactions; while 

the vast importance of the trust and the operation of treaties as 

laws plead strongly for the participation of the whole or a 

portion of the legislative body in the office of making them.

The Federalist No. 75, at 450-51 (A. Hamilton) (C. Rossiter ed. 1961); see also

The Federalist No. 64, at 390-93 (J. Jay); The Federalist No. 66, at 402-03 (A. 

Hamilton); see generally Congressional Research Service, Treaties and Other

International Agreements: The Role o f the United States Senate, 98th Cong., 2d 

Sess. 25-28 (Comm. Print prepared for the Senate Comm, on Foreign Relations, 1984) (CRS Study). Rather than vest either Congress or the President 

with the sole power to make treaties, the Framers sought to combine the 

judgment of both, providing that the President shall make the treaties, but 

subject to the “advice and consent” of the Senate. Thus, the Framers included 

the Senate in the treaty-making process because the result of that process, just 

as the result of the legislative process, is essentially a law that has “the effect of 

altering the legal rights, duties and relations of persons . . . outside the Legislative Branch.” INS v. Chadha, 462 U.S. at 952. As discussed above, however, 

conceptually the constitutional division of treaty-making responsibility between the Senate and the President is essentially the reverse of the division of 

law-making authority, with the President being the draftsman of the treaty and 

the Senate holding the authority to grant or deny approval.

III. Senate Practice

In practice, the Senate’s formal participation in the treaty-making process 

begins after negotiation of the treaty.7 At that time, the President transmits the 

treaty to the Senate, with a detailed description and analysis of the treaty, and 

any protocols, annexes, or other documents that the President considers to be 

integral parts of the proposed treaty. See CRS Study at 105. Under the Senate’s 

rules, treaties are referred to the Senate Foreign Relations Committee,8 which

7 President W ashington attempted to consult with the Senate, with limited success, on the negotiation of 

several treaties with the Indians. By 1816 the practice had become firmly established (hat the Senate would 

grant its “advice and consent” to treaties already negotiated by the President or his representatives. See

Henkin at 131-132; CRS Study at 34-36.

8 Although jurisdiction to review treaties is vested solely in the Foreign Relations Committee, Rule 25, 

Standing Rules of the Senate, S. Doc. No. 99-13, 99th Cong., 1st Sess. (1985), upon occasion other 

committees have asserted an interest in the subject matter of the treaty, even though they have no jurisdiction 

to make formal recommendations. For example, the Senate Armed Services Committee has held extensive 

hearings on the “m ilitary implications” of various treaties, including the ABM and SALT II treaties. See

Hearings on the Military Implications of the Treaty on the Limitations of Antt-Ballistic Missile Systems and

the Interim Agreement on Limitation o f Strategic Offensive Arms before the Senate Comm on Armed

Services, 92d Cong., 2d Sess. (1972); Hearings on the Military Implications o f the Treaty on the Limitation of

Strategic Offensive Arms and Protocol Thereto before the Senate Comm, on Armed Services, 96th Cong , 1 st 

Sess. (1979); see generally CRS Study at 106-07.

31
may hold hearings to develop a record explaining the purposes, provisions, and 

significance of the agreement. Typically, the principal witnesses at such hearings are representatives of the Executive Branch. The Foreign Relations Committee then issues a report to the full Senate, with its recommendation on 

approval of the treaty.

The Senate’s practice has been to approve, to disapprove, or to approve with 

conditions, treaties negotiated by the Executive Branch. Express conditions 

imposed by the Senate may include “understandings,” which interpret or 

clarify the obligations undertaken by the parties to the treaty but do not change 

those obligations,9 or “reservations” and “amendments,” which condition the 

Senate’s consent on amendment or limitation of the substantive obligations of 

the parties under the agreement.10 On occasion, the Senate has accompanied its 

consent by “declarations,” which state the Senate’s position, opinion, or intention on issues raised by the treaty, although not on the provisions of the specific 

treaty itself.11 See CRS Study at 110.

IV. Melevamce off tine Semsitte RatifficattijM Eecord

A. Express Conditions

When the Senate includes express conditions as part of its resolution of 

consent to ratification, the President may, if he objects, either refuse to ratify 

the treaty or resubmit it to the Senate with the hope that it will be approved 

unconditionally the second time. See 14 M. Whiteman, Digest o f International

Law, 138 (1970). If the President proceeds with ratification, however, such 

understandings or other conditions expressly imposed by the Senate are generally included by the President with the treaty documents deposited for ratification or communicated to the other parties at the same time the treaty is 

deposited for ratification.12 See id. at 188-93. Because such conditions are

9 See generally CRS Study at 11, 109-110; S. Rep. No. 47, 96th C ong., 1st Sess. 13-25 (1979) (Panama 

C anal Treaty); S. Rep. No. 29, 97th Cong., 1st Sess. 45 (1981) (SALT II Treaty).

10See generally CRS Study at 109-110; Henkin at 134 & n.23 (1972); S. Rep. No. 4 7 ,96th Cong., 1st Sess. 

2 4-25 (Panam a Canal Treaty); S. Rep. No. 29, 97th Cong., 1st Sess. 44-45 (SALT II Treaty).

11 Such “declarations," which do not purport to interpret the treaty but only to express a “sense o f the 

Senate” with respect to related issues, m ay or may not be included by the President in the instrument of 

ratification subm itted to the other parties. See, e.g., CRS Study at 110 & n.10 (discussing 1976 Treaty of 

Friendship and Cooperation with Spain).

12 Treaties usually require international action such as the exchange o r deposit of instruments o f ratification 

in order to establish international obligations. See 14 W hiteman, supra, at 62; Vienna Convention on the Law 

o f Treaties, art. 2. In general, conditions that alter the obligations of a party under the treaty must be presented 

with the treaty documents. See 14 M. W hitem an, supra, at 188-193. “Understandings” or “declarations,” 

w hich only clarify the meaning of a treaty provision or describe a policy, rather than alter the meaning o f the 

treaty, are generally communicated to the other parties, but are not necessarily included with the official 

treaty docum ents. Id. In 1976, the President communicated five Senate “declarations” relating to the Treaty 

o f Friendship and Cooperation with Spain o f 1976, 27 U.S.T. 3005, T.I.A.S. No. 8360, separately from the 

ratification, explaining that he viewed the declarations as appropriate “statements of hope and expressions of 

opinion” and as “statem ents of domestic United States processes.” [1976] Digest o f U.S. Practice in

International Law 214—17 (described in Restatement (Revised) § 314, n .l). The Senate Foreign Relations

Continued

32
considered to be part of the United States’s position in ratifying the treaty, they 

are generally binding on the President, both internationally and domestically, 

in his subsequent interpretation of the treaty.13 See generally United States v. 

Schooner Peggy, 5 U.S. (1 Cranch) 103,107 (1801); H aver\. Yaker, 76 U.S. (9 

Wall.) 32,35 (1869); Hidalgo County Water Control and Improvement District

No. 7 v. Hedrick, 226 F.2d 1, 8 (5th Cir. 1955); Restatement (Revised) § 323.

B. Statements in the Ratification Record

The more difficult question is what relevance, if any, the President must give 

to less formal, contemporaneous indications of the Senate’s understanding of 

the treaty, i.e., statements in committee reports, hearings, and debates which 

may reflect an understanding of certain treaty provisions by some Senators, but 

which were not embodied in any formal understanding or condition approved 

by the entire Senate.14 With the not insubstantial exception of representations 

made or confirmed by the Executive Branch (discussed below), we believe 

such statements have only limited probative value and therefore are entitled to 

little weight in subsequent interpretations of the treaty.15

12 ( . . . continued)

Committee has criticized this practice in the past, and has recommended a three-tiered categorization o f 

conditions: (1) those that do not directly involve formal notice to or agreement by the other parties; (2) those 

that would be formally communicated to the other parties as official statements o f the position o f the United 

States in ratifying the treaty, but that do not require their agreement; and (3) those that would require the 

explicit agreement o f the other parties for the treaty to come into force. S. Exec. Rep. 96-14, 96th Cong., 1st 

Sess. 18, 28 (1979).

i3This presumes, o f course, that the condition is within the Senate's authority to impose as part o f its treatymaking authority. The Senate’s authority to impose conditions is not unlim ited merely because it may 

withhold its consent. The general principle that Congress cannot attach unconstitutional conditions to a 

legislative benefit or program merely because it has authority to withhold the benefit or power entirely 

applies equally to the Senate’s advice and consent authority. See generally Wong Wing v. United States, 163 

U.S. 228, 237 (1896); Myers v. United States, 272 U.S. 52, 126(1926). The Senate may not, for example, use 

its advice and consent power to impose conditions that affect separate, wholly domestic, statutory schemes. 

See Power Authority v. Federal Power Comm'n, 247 F.2d 538 (D.C. Cir.), vacated as moot sub nom.

American Pub. Power Association v. Power Authority, 355 U.S. 64 (1957). As we have advised before, we do 

not believe the Senate may impose conditions that interfere with the President’s responsibility to execute the 

laws. See “C onstitutionality of Proposed Conditions to Senate Consent to the Interim Convention on 

Conservation of North Pacific Fur Seals,” 10 Op. O.L.C. 12 (1986).

14 It is clear that post hoc expressions of legislative intent, after the treaty has been duly ratified, cannot 

change the legal effect o f an international agreement to which the Senate Has given its approval. See Fourteen

Diamond Rings v. United States, 183 U.S. 176, 179-180 (1901) (resolution adopted by Congress after the 

Senate had consented to ratification of a treaty is “absolutely without legal significance”). Congress may, o f 

course, in effect validate an Executive Branch interpretation of a treaty by passing legislation consistent with 

that view. See generally Foster <£ Elam v. Neilson, 27 U.S. (2 Pet.) 253, 309 (1830).

13 We note that while a few courts have alluded to the record the Senate creates in advising and consenting 

to the ratification o f treaties, none has advanced a comprehensive theory of what weight should be given to 

particular portions o f the ratification record and none, to our knowledge, has specifically relied on representations in the Senate record to support a particular construction o f a treaty. See Hidalgo County Water Control

& Improvement District v. Hedrickt 226 F.2d at 8 (refusing to consider evidence from Senate hearings, 

committee discussions, and debates because the meaning of the treaty was otherwise clear); Coplin v. United

States, 6 Ct. Cl. 115, 144 (1984), rev’d on other grounds, 761 F.2d 688 (Fed. Cir. 1985), a f f d sub nom.

O'Connor v. United States, 479 U.S. 27 (1986) (reviewing Senate “legislative history” of the Panama Canal 

Treaty but finding that it was entitled to little weight).

33
First, it must be observed that a treaty is fundamentally a “contract between 

or among sovereign nations,” 16 and the primary responsibility — whether of 

the executive or the courts — is “to give the specific words of the treaty a 

meaning consistent with the shared expectations of the contracting parties.” Air

France v. Saks, 470 U.S. 392, 399 (1985). See generally Foster & Elam v. 

Neilson, 27 U.S. (2 Pet.) 253, 314 (1830) (“A treaty is in its nature a contract 

between two nations, not a legislative act.”). International agreements, like 

“other contracts . . . are to be read in the light of the conditions and circumstances existing at the time they were entered into, with a view to effecting the 

objects and purposes of the States thereby contracting.” Rocca v. Thompson,

223 U.S. 317, 331-332 (1912). Necessarily, the best evidence of the intent of 

the parties is the language and structure of the treaty and, secondarily, direct 

evidence of the understanding reached by the parties, as reflected in the 

negotiating record and subsequent administrative construction,17 rather than 

unilateral, post-negotiation statements made during the Senate ratification 

debates.

Moreover, the constitutional role of the Senate is limited to approval or 

disapproval of the treaty, much as the President’s constitutional role in enacting domestic legislation is limited to his veto power. The Senate may, if it 

chooses, amend or interpret the treaty by attaching explicit conditions to its 

consent, which are then transmitted to, and either accepted or rejected by, the 

other parties. Absent such conditions, the Senate does not participate in setting 

the terms of the agreement between the parties, and therefore statements made 

by Senators, whether individually in hearings and debates or collectively in 

committee reports, should be accorded little weight unless confirmed by the 

Executive. We note that even in the case of domestic legislation, where Congress — rather than the President and other foreign governments — directly 

shapes the operative language, “[r]eliance on legislative history in divining the 

intent of Congress is ... a step to be taken cautiously.” Piper v. Chris-Craft

Industries, Inc., 430 U.S. 1, 26 (1977).18

16 TWA, Inc. v. Franklin Mint Corp., 466 U.S. 243, 262 (1984) (Stevens, J., dissenting); Washington v. 

Fishing Vessel A ss’n, 443 U.S. 658, 675 (1979).

17 See generally O ’Connor x. United States, 479 U.S. 27, 31-33 (1986); Air France v Saks, 470 U.S. at 396; 

Maximov v. United States, 373 U.S. 49, 54 (1963); Kolovrat v Oregon, 366 U.S. at 194; Factor v. 

Laubenheimer, 290 U.S. at 294; Jones v. Meehan, 175 U.S. at 4, 23.

18 For exam ple, “ordinarily even the contem poraneous remarks of a single legislator . . . are not controlling 

in analyzing legislative history.” Consumer Products Safety Comm'n v. GTE Sylvama, 447 U.S. 102, 118 

(1980). As the Court stated in Weinberger v. Rossi, 456 U.S. 25 (1982):

[0 ]n e isolated remark by a single Senator, am biguous in meaning when examined in context, is 

insufficient to establish the kind o f affirmative congressional expression to evidence an intent to 

abrogate provisions in 13 international agreements.

Id. at 35. Sim ilarly, statem ents made during legislative hearings provide oniy limited guidance as to the intent 

or understanding o f the Senate as a w hole. See, e.g , McCaughn v. Hershey Chocolate Co., 283 U.S. 488, 

493-494 (1931); Austasia Intermodel Lines, Ltd. v. CFMC, 580 F.2d 642, 645 (D C. Cir. 1978). Committee 

reports provide im portant evidence o f the legislative intent, but are at best “only aids” in interpreting 

am biguous statutory language. See Abourezk v. Reagan, 785 F 2d 1043 (D.C. Cir. 1986); General Motors

Corp. v. Ruckelshaus, 742 F.2d 1561 (D .C. Cir. 1984), cert, denied, 471 U.S 1074 (1985); NLRB v. ResCare, Inc., 705 F.2d 1461 (7th O r. 1983); Mills v. United States, 713 F.2d 1249 (7th Cir. 1983), cert, denied,

464 U.S. 1069(1984).

34
Indeed, profound foreign policy implications would be raised if the United 

States were to supplement or alter treaty obligations to foreign governments 

based on statements made by members of the Senate during its consideration of 

the treaty that were not communicated to those governments in the form of 

express conditions. “[F]oreign governments dealing with us must rely upon the 

official instruments of ratification as an expression of the full intent of the 

government of the United States, precisely as we expect from foreign governments.” Coplin v. United States, 6 Ct. Cl. at 145. In New York Indians v. United

States, 170 U.S. 1, 22-23 (1898), for example, the Supreme Court refused to 

give effect, vis-a-vis the Indians, to a proviso adopted by the Senate but not 

included in the treaty documents subsequently presented to the Indians for their 

acceptance:

There is something . . . which shocks the conscience in the idea 

that a treaty can be put forth as embodying the terms of an 

arrangement with a foreign power or an Indian tribe, a material 

provision of which is unknown to one of the contracting parties, 

and is kept in the background to be used by the other only when 

the exigencies of a particular case may demand it. The proviso 

never appears to have been called to the attention of the tribes, 

who would naturally assume that the treaty, embodied in the Presidential proclamation contained all the terms of the arrangement.

We can well imagine that the United States would be deeply disturbed if the 

Soviet Union resolved ambiguities in a treaty by reference to deliberations in a 

Soviet legislative body charged with consenting to its ratification.19 If individual Senators believe that portions of a treaty are ambiguous, they may 

resolve that ambiguity in a manner consistent with the mutual process through 

which treaties are negotiated: either by requesting the Executive to state more 

clearly the meaning of the agreement it has reached with the foreign country, or 

by making explicit the Senate’s understanding of the provision through a 

formal reservation or understanding attached to its resolution of approval. 

Thus, while statements made by individual senators or even in committee 

reports may at times provide a gloss on other, more direct sources of evidence 

of a treaty’s meaning, we believe they are entitled to little weight in and of 

themselves.20

On the other hand, statements made to the Senate by representatives of the 

Executive Branch as to the meaning of a treaty should have considerably more

19Consistent with this view, when questions arose concerning the Panamanian interpretation of certain key 

provisions o f the Panama Treaties, the State Department took the position that the United States would rely 

on the final instruments o f ratification as expressing the full intent of the parties. See CRS Study at 128 &

n.62.

20 The latest tentative draft of the Restatement takes the position that “indication in the record that the 

Senate ascribed a particular meaning to the treaty is relevant to the interpretation of the treaty by a United 

States court in much the same way that the legislative history of a statute is relevant to its interpretation.” See

Restatement (Revised) § 314, comment d (Tentative Final Draft). As the discussion makes clear, we believe 

the Restatement position exaggerates somewhat the general evidentiary significance of the Senate ratification 

record in interpreting ambiguous provisions of an international treaty.

35
weight in subsequent interpretations of ambiguous terms of the treaty. Such 

statements do not present as substantial a threat to the reliance interests of 

foreign governments, because the Executive Branch negotiated the treaty and 

is therefore in a position to represent authoritatively the meaning of the agreement that emerged from the negotiating process. Moreover, given that the 

Senate’s constitutional role is limited to approving a treaty already negotiated 

by the Executive Branch and that much of the extra-textual evidence of a 

treaty’s meaning remains in the control of the Executive Branch, we believe the 

Senate itself has a substantial reliance interest in statements made by the 

Executive Branch officials seeking that approval.

Accordingly, consistent with the President’s role as the nation’s exclusive 

negotiator of treaties with foreign governments, we believe that statements 

made to the Senate by the Executive Branch during the ratification debates are 

relevant in much the same way that contemporaneous statements by congressional draftsmen or sponsors of domestic legislation are relevant to any subsequent interpretation of the statute. See, e.g., FEA v. Algonquin SNG, Inc., 426 

U.S. 548, 564 (1976) (statement by one of legislation’s sponsors “deserves to 

be accorded substantial weight in interpreting the statute”); National Woodwork Manufacturers Ass’n v. NLRB, 386 U.S. 612, 640 (1967); Schwegmann

Bros. v. Calvert Distillers Corp., 341 U.S. 384, 394-395 (1951). We note that 

because of the primary role played by the Executive Branch in the negotiation 

of treaties and the implementation of foreign policy, courts generally accord 

substantial deference — albeit not conclusive effect — to interpretations 

advanced by the Executive Branch. “While courts interpret treaties for themselves, the meaning given them by the departments of government particularly 

charged with their negotiation and enforcement is given great weight.” Kolovrat

v. Oregon, 366 U.S. at 194; see also Sumitomo Shoji America, Inc. v. Avagliano,

457 U.S. 176, 185 (1982); Collins v. Weinberger, 707 F.2d 1518, 1522 (D.C. 

Cir. 1983) (“Courts should defer to such executive actions [interpreting a 

treaty] provided they are not inconsistent with or outside the scope of the 

treaty.”); Restatement (Revised) § 326, comment b. Although the courts often 

rely on interpretative statements made by the Executive Branch prepared well 

after negotiation and ratification of the treaty,21 they find particularly persuasive a consistent pattern of Executive Branch interpretation, reflected in the 

application of the treaty by the Executive and the course of conduct of the 

parties in implementing the agreement. See, e.g., O ’Connor v. United States,

479 U.S. at 32-33. Much as contemporaneous administrative construction of 

domestic statutes by agencies charged with their implementation is generally 

accorded considerable deference by the courts, particularly when those agencies have made explicit representations to Congress during consideration of the

21 O n occasion, the State Department makes specific suggestions to the court about the interpretation of an 

agreem ent. See, e.g., Caplin v. United Stales, 761 F.2d 688, 691 (Fed. Cir. 1985), a jfd su b nom. O ’Connor v. 

United States, 479 U.S 27 (1986). The courts in fact often invite the United States to file amicus briefs giving 

the views o f the Executive Branch in cases to which the United States is not a party. See, e.g., Sumitomo Shoji

America, Inc. v. Avagliano, 457 U.S. 176 (1982); Zschemig v. Miller, 389 U.S. 429 (1968); Kolovrat v. 

Oregon, 366 U.S. 187 (1961).

36
legislation,22 statements made to the Senate by members of the Executive 

Branch about the scope and meaning of a treaty would be relevant evidence of 

the Executive Branch’s view, and therefore would be accorded deference by a 

court in assessing the domestic effect of the treaty.

The weight to be given to an interpretative statement made by an Executive 

Branch official to the Senate during the ratification process will likely depend 

upon such factors as the formality of the statement, the identity and position of 

the Executive Branch official making the statement, the level of attention and 

interest focused on the meaning of the relevant treaty provision, and the 

consistency with which members of the Executive Branch adhered at the time 

to the view of the treaty provision reflected in the statement.23 All of these 

factors affect the degree to which the Senate could reasonably have relied upon 

the statement and, in turn, the weight that courts will attach to it. At one 

extreme, a single statement made by a middle-level Executive Branch official 

in response to a question at a hearing would not be regarded as definitive. 

Rather, in interpreting the domestic effect of a treaty, the courts would likely 

accord such a statement in the ratification record a degree of significance 

subordinate to more direct evidence of the mutual intent of the parties, such as 

the language and context of the treaty, diplomatic exchanges between the 

President and the other treaty parties, the negotiating record, and the practical 

construction of the provision reflected in the parties’ course of dealings under 

the treaty. Moreover, courts often give substantial weight to the Executive 

Branch’s current interpretation of the treaty, in recognition of the President’s 

unique role in shaping foreign policy and communicating with foreign governments,24 and, accordingly, would be unlikely to bind future chief executives on 

the basis of an isolated remark of an Executive Branch official in a previous 

administration. In general, therefore, less formal statements made by the Executive Branch before the Senate (such as the one described in the preceding 

hypothetical) will be but one source of relevant evidence to be considered in 

interpreting an ambiguous treaty provision.

In contrast, in a case in which the statements by the Executive Branch 

amount to a formal representation by the President concerning the meaning of a 

particular treaty provision, the ratification record may be conclusive. If, for 

example, the ratification record unequivocally shows that the President presented the treaty to the Senate based on specific, official representations 

regarding the meaning of an ambiguous provision, that the Senate regarded that

22 See, e.g.. United States v. Vogel Fertilizer Co., 455 U.S. 16, 30 (1982) (court necessarily attaches great 

weight to agency representations to Congress when the administrators participated in drafting the statute and 

directly m ade known their views to Congress); Dawson Chemical Co. v. Rohm & Haas Co., 448 U.S. 176, 

202-212 (1980) (statements by administration witnesses during hearings on patent infringement legislation 

strongly reinforce the court’s conclusion that Congress intended to immunize respondent’s behavior from 

patent misuse charges). In general, courts give “great w eight” in construing domestic statutes to contemporaneous constructions by the executive branch. See generally Udall v. Tollman, 380 U.S. 1,16 (1965); Red Lion

Broadcasting Co. v. FCC, 395 U.S. 367, 381 (1969).

23 Sim ilarly, the weight of statements by senators confirmed by the executive will depend, inter alia, on the 

formality o f the confirm ation and the identity and position of the person confirming the statement.

24 See, e.g., Sumitomo Shoji America, Inc. v. Avagliano, 457 U.S. at 184 n. 10.

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understanding as important to its consent, and that the Senate relied on the 

representations made by the Executive Branch in approving the treaty (and thus 

in refraining from attaching a formal reservation setting forth the understanding), we believe the President would, in effect, be estopped from taking a 

contrary position in his subsequent interpretation of the treaty, just as he would 

be bound by a formal reservation or understanding passed by the Senate to the 

same effect. See generally United States v. Vogel Fertilizer Co., 455 U.S. at 31 

(refusing to uphold current Treasury Department interpretation in light of 

evidence that the Treasury Department proposed and presented the legislation 

to Congress on a different understanding). Obviously, a President could not 

negotiate a treaty with other nations on the basis of one understanding of its 

import, submit the treaty to the Senate on a wholly different understanding, and 

then, in implementing the treaty, rely solely on the understanding he had 

reached with the other parties. Similarly, he could not reach a secret agreement 

with the other party that substantially modifies the obligations and authorities 

created by the text of the treaty submitted to the Senate, and then seek to use the 

secret agreement as a basis for actions inconsistent with the text of the treaty. 

Such results would essentially eviscerate the Senate’s constitutional advice and 

consent role, because it would deprive the Senate of a fair opportunity to 

determine whether, or with what conditions, the treaty should become the 

“supreme Law of the Land.” Accordingly, in such extreme cases, we have little 

doubt that, as a matter of domestic law, the courts would construe the treaty as 

presented to and accepted by the Senate, even if as a matter of international law 

the treaty might have a different meaning.25

C h a r l e s J. C o o p e r

Assistant Attorney General

Office o f Legal Counsel

25 Although courts generally seek to construe treaties consistent w ith their international import, on occasion 

courts have adopted constructions o f particular treaties that conflict with the President's view of the 

international obligations created by the treaty. See, e.g., Maiorano v. Baltimore & Ohio R.R., 213 U.S. 268 

(1909) (interpreting an 1871 treaty w ith Italy giving aliens access to courts of justice). Moreover. Congress 

can enact dom estic legislation that is inconsistent with existing treaty obligations, and thus has the effect of 

tying the P resident's hands domestically, while leaving the international obligations intact. See generally

Menominee Tribe o f Indians v. United States, 391 U.S. 404, 412-413 (1968); Moser v. United States, 341 

U.S. 41, 45 (1951); Torres v INS, 602 F.2d 190, 195 (7th Cir. 1979). It would nnt be unprecedented, 

therefore, fo r a court to construe a treaty more narrowly — or more broadly — as a matter o f domestic law 

than the President construes the treaty as a matter of international law. As Professor Henkin has observed, 

“[i]t could happen . . . that Congress and the courts would in effect apply treaty provisions different from 

those that bind the United States internationally — another cost of the separation o f powers.” Henkin at 167.

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