¹ Arnold McNair, The Law of Treaties 15 (1961). As an example, he referred to the Memorandum of Understanding regarding German Assets in Italy, Mar. 29, 1957, UK-Fr.-It.-U.S., 8 UST 445, 283 UNTS 137. See also Hans Blix & Jirina H. Emerson, The Treaty Maker’s Handbook 7, 316 (1973) (listing MOUs as a type of instrument resembling treaties).

² The Department of State lists some 22 defense MOUs with the United Kingdom as being currently in force; this number includes MOUs covering, for example, the legal status of personnel and the procurement of airborne early-warning systems, as well as the provision of mutual logistic support, supplies and services. Office of the Legal Adviser, U.S. Dep’t of State, Pub. No. 9433, Treaties in Force 259–62 (1994). An example of a U.S.-UK MOU registered with the United Nations pursuant to Article 102 of the Charter is the quite minor, but perhaps not atypical, MOU regarding support by the 15th Air Base Wing to the Royal Air Force detachment at Hickam Air Force Base, Apr. 21, 1981, 33 UST 998, 1285 UNTS 97. See also infra note 11.

³ First Memorandum of the United Kingdom of Great Britain and Northern Ireland, U.S./UK Arbitration concerning Heathrow Airport User Charges, para. 5.143, at 108–09 (May 31, 1990) (on file with author). For details of the arbitration, see Contemporary Practice of the United States Relating to International Law, supra p. 738, and text at and note 12 infra.

⁴ See Geoffrey Marston, United Kingdom Materials on International Law 1989, 60 Brit. Y.B. Int’l L. 569, 581 (1989). For a fuller description of internal UK legal considerations, see Anthony Aust, The Theory and Practice of Informal International Instruments, 35 Int’l & Comp. L.Q. 787 (1986).

⁵ Memorandum from the Assistant General Counsel (International and Intelligence), Department of Defense, to the General Counsels and Judge Advocates General of the Military Departments, General Counsels of the Defense Agencies and the Legal Counsel to the Chairman, Joint Chiefs of Staff (Oct. 31, 1991) (on file with author) (addressing international agreements with the United Kingdom and other countries).

⁶ 22 U.S.C. §2767(b)(1)–(2) (1988).

⁷ 22 U.S.C. §2767a(d)(1) (1988).

⁸ See Vienna Convention on the Law of Treaties, opened for signature May 23, 1969, Art. 2(1)(a), 1155 UNTS 331, reprinted in 8 ILM 679, 681 (1969). The International Law Commission’s quoted Commentary on the final draft of this provision, which did not change in the adopted text, is found in Report of the International Law Commission to the General Assembly, [1966] 2 Y.B. Int’l L. Comm’n 188, UN Doc. A/CN.4/SER.A/1966/Add.1. It may be noteworthy that some leading British commentators have recently taken the view that the ILC draft (in no small measure the product of British international law expertise itself) may not have been “wholly correct” in stating that an MOU “was ‘undoubtedly’ an international agreement subject to the law of treaties.” 1 Oppenheim’s International Law 1209 n.8 (Robert Jennings & Arthur Watts eds., 9th ed. 1992). It has been noted that some 30 different names for treaties have been identified; their use has usually been a matter of diplomatic nuance. Shabtai Rosenne, Vienna Convention on the Law of Treaties, in [Installment] 7 Encyclopedia of Public International Law 525, 527 (Rudolf Bernhardt ed., 1984).

⁹ In a recent submission to the U.S. Senate, the Department of State offered the following with regard to this distinction:

Dep’t of State, Article-by-Article Analysis of START Documents 352 (1991), reprinted in S. Treaty Doc. No. 20, 102d Cong., 1st Sess. 1086 (1991).

¹⁰ The British view of the importance of such indicia of the intent to be bound is reflected in a list of terms produced by the UK Ministry of Defence early in 1991. According to this list, numerous terms were to be avoided/replaced to render MOUs not legally binding. Some of the more predictable substitutions recommended were: “arrangements” for “agreements” and “will” for “shall”; however, it is not at all clear what determinative results would flow from such other recommendations as substituting “paragraph” for “clause,” “section” for “article,” “mutually consents” for “under takes,” “provisions” for “terms/conditions” or “come into effect” for “enter into force.” Memorandum from Ministry of Defence to British Army Staff (Washington), Ann. A (Feb. 27, 1991) (on file with author). Indeed, such distinctions without apparent difference well illustrate the British approach to this issue, which was criticized in the U.S. Reply Memorandum in the Heathrow arbitration as unwarranted British reliance “on esoteric semantic distinctions not accepted by USG and unknown to the law of treaties.” Reply Memorandum of the United States, U.S./UK Arbitration concerning Heathrow Airport User Charges 101 (Nov. 9, 1990) (on file with author).

¹¹ For example, the MOU cited supra note 2 speaks of “this agreement,” records responsibility for claims, and the like.

¹² Award on the First Question, U.S./UK Arbitration concerning Heathrow Airport User Charges, ch. 5, paras. 6.7–6.8, at 155–56 (Nov. 30, 1992) (on file with author). Among the factors noted by the tribunal were that the MOU had not been published and had not been registered under Article 102 of the UN Charter or with the International Civil Aviation Organization under Article 83 of the Chicago Convention. Id., para. 6.5, at 155. But see U.S.-UK Exchange of Notes, para, (b) (Mar. 11, 1994) (on file with author), terminating the Heathrow arbitration, recording that the MOU of April 6, 1983, “will cease to have effect.” This language suggests the awareness of both sides that the MOU, despite the tribunal’s award, might retain legal effect that would continue to exist unless termination occurred. Accordingly, it would not appear correct to consider this award as evidence for the proposition that MOUs are not legally binding per se.

¹³ This authority is implemented subject to appropriate consultation with the Department of State, pursuant to the Case-Zablocki Act, 1 U.S.C. §112b (1988).

¹⁴ Recent United Kingdom practice is officially summarized in Directorate of Legal Affairs, Council of Europe, Expression of Consent by States to be Bound by a Treaty 98–102 (1987).

¹⁵ Defense Cooperation Arrangements Agreement, May 27, 1993, U.S.-UK, Hein’s No. KAV 3575, 1993 Gr. Brit. TS No. 69 (Cm 2361), Temp. State Dep’t No. 93–116. A similar U.S.-Canada Agreement to Facilitate the Process of Cooperation in Defense Matters entered into force on August 19, 1994 (on file with author).

¹⁶ Id. at 1.

¹⁷ Agreement between the Parties to the North Atlantic Treaty Regarding the Status of their Forces, June 19, 1951, 4 UST 1792, 199 UNTS 67.

¹⁸ Defense Cooperation Arrangements Agreement, supra note 15, at 1–3.

¹⁹ Id. at 3.