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Oppenheim's International Law - Volume 1 Peace, 9th Edition edited by Jennings, Robert; Watts KCMG QC, Arthur (19th June 2008)

Part 4 International transactions, Ch.14 Treaties, Form and Parts of Treaties

Sir Robert Jennings qc, Sir Arthur Watts kcmg qc

From: Oppenheim's International Law: Volume 1 Peace (9th Edition)

Edited By: Robert Jennings, Arthur Watts KCMG QC

From: Oxford Public International Law (http://opil.ouplaw.com). (c) Oxford University Press, 2015. All Rights Reserved. Subscriber: null; date: 10 December 2019

Treaties, reservations and declarations — Treaties, entry into force

(p. 1207) Form and Parts of Treaties

Satow, International Congresses (Foreign Office Peace Handbook) (1920), pp 20–32 Report of Mastny and Rundstein for the League Codification Committee, AJ, 20 (1926), Special Suppl, pp 205–18 Harv Research (1935, pt III), pp 722–39 Devaux, RIF, i (1936), pp 299–309 Mervyn Jones, BY, 21 (1944), pp 111–22 UN Legislative Series, Laws and Practices concerning the Conclusion of Treaties (1953) McNair, Treaties, pp 7–34 Higgins, The Development of International Law through the Political Organs of the United Nations (1963), pp 254–9.

§ 585  Form of treaties

International law prescribes no necessary form for treaties. The Vienna Convention on the Law of Treaties defines ‘treaty’ as an agreement ‘in written form’.1 This does not prejudice the legal force of an oral agreement or the application thereto of any rules of the Convention to which they would be subject under international law independently of the Convention.2 In modern practice, treaties are in writing and are usually3 signed by duly authorised representatives of the contracting parties. While the more formal treaty instruments tend to follow a similar pattern4 there is no required standard form.5 The parties are free to agree upon the language or languages in (p. 1208) which the treaty is expressed, and upon which (if any) of them is to be regarded as authentic or as prevailing in case of dispute.6 In the Temple of Preah Vihear Case (Preliminary Objections) the International Court of Justice said that ‘Where … as is generally the case in international law, which places the principal emphasis on the intention of the parties, the law prescribes no particular form, parties are free to choose what form they please provided their intention clearly results from it.’7

§ 586  Acts, conventions, declarations, exchanges of notes, etc

International agreements may be given a variety of designations, such as treaties, agreements, Acts, conventions, declarations1 and protocols.2 These various designations are used in no consistent manner.3 Although the designations may indicate the level of importance which the parties attach to an instrument, designation alone4 does not in international law5 affect the binding force of the instrument or its characterisation as a treaty; this is made clear in Article 2.1(a) of the Vienna Convention on the Law of Treaties. In the South West Africa Cases (Preliminary Objections) the International Court of Justice said: ‘Terminology is not a determinant factor as to the character of an international agreement or undertaking. In the practice of States and of international organisations and in the jurisprudence of international courts, there exists a great variety of usage; there are many different types of acts to which the character of treaty stipulations has been attached’.6 Apart from the more obvious types of such Acts, mentioned above, even an unsigned (p. 1209) and uninitialled document such as a press communiqué may constitute an international agreement.7

Consequently, states cannot avoid an instrument being a treaty merely by giving it a title suggesting otherwise. They may, however, still adopt instruments which do not constitute treaties, provided that as a matter of substance and not of mere nomenclature the instruments are appropriate to such a conclusion.8 This is (p. 1210) particularly important in the case of exchanges of notes. Diplomatic notes are often sent in the normal course of diplomatic business and notes in reply are just as often returned. Some such exchanges — but by no means a majority — take a form9 such that the two notes taken together constitute an agreement, and it is these which fall within the definition of ‘treaty’ for purposes of the Vienna Convention.10 The entry into force of exchanges of notes constituting an agreement is frequently stated to be dependent upon signature alone, without any need for ratification, and this practice makes this manner of recording an agreement particularly suitable where the expeditious conclusion and execution of an agreement is required, or for the regulation of technical or less important matters for which a more formal instrument might be inappropriate.

§ 587  Parts of treaties

International law lays down no rules concerning the arrangement of the parts of treaties. However, in the more formal treaties the following order is usually observed. After the title,1 a first part, known as the preamble,2 comprises the names of the contracting parties (and sometimes their duly authorised representatives), and the motives for the conclusion of the treaty.3 A second part consists of the principal provisions, in numbered articles, and perhaps supplemented by annexes. A third part — usually referred to as ‘final clauses’ — consists of miscellaneous provisions concerning the duration of the treaty, its ratification, the accession of third states, and the like.3a The last part — (p. 1211) the testimonium — comprises the signatures of the representatives. However, this order is by no means essential. In the past, treaties have sometimes contained secret stipulations in an additional part;4 this practice must tend to disappear having regard to the requirement of registration and publication.5 It is a question of construction whether in any particular case an instrument referred to in a treaty forms, in the intention of the parties, an integral part of the treaty.6 In the Ambatielos case the International Court of Justice held that a Declaration annexed to a Treaty of 1926 between the United Kingdom and Greece and providing for the settlement by arbitration of disputes based on a Treaty of 1886 was, in the circumstances of the case, an integral part of the former treaty.7


Article 2.1(a). Similarly Art 2 of the Pan-American Convention on Treaties (see § 27, n 11.

Article 3. See generally on oral agreements, Sørensen, Hag R, 101 (1960), iii, at pp 54–8; McNair, Treaties, pp 7–11, and § 582, n 13. On the binding character of the Ihlen declaration and other unilateral statements, see § 459, n 4. Note the observation in the Joint Dissenting Opinion of Judges Hackworth, Badawi, Carneiro and Rau in the case concerning Rights of United States Nationals in Morocco that ‘usage and sufferance are only different names for agreement by prolonged conduct, which may be no less binding than agreement by the written word’: ICJ Rep (1952), p 220. One should probably distinguish the question whether oral statements, or unilateral declarations, create a legal obligation, from the question whether they constitute treaties or agreements: see the Separate Opinions of Judges Spender and Fitzmaurice in the South West Africa Cases (Preliminary Objections), ICJ Rep (1962), at pp 474–9.

In some cases a text may be adopted, and subsequently acceded to without any signature being appended, as with the Convention on the Privileges and Immunities of the UN: see McNair, Treaties, p 123. Some states, like Mexico and Turkey, became bound by the wide obligations of the Covenant simply by accepting the invitation to join the League without any formal document of adhesion having been executed.

See § 587.

As to agreements in simplified form see Hamzeh, BY, 43 (1968–69), pp 179–90; Smets, La Conclusion des accords en forme simplifiée (1969). Within the EC the member states have developed the practice of adopting ‘Decisions of Representatives of the Governments of the Member States meeting within the Council [of the European Communities]’ (as distinguished from decisions of the Council as an organ of the Communities): these decisions are regarded as international agreements in simplified form. The decisions are not signed by the individual member states, but only by the President-in-Office of the Council. In the USA-France Air Transport Services Agreement Arbitration, an agreement was considered to have come into being tacitly, by consent to a timetable: (1963), ILR, 38, p 182. See also German-Swiss Extradition Case (2) (1968), ILR, 60, p 314. There probably is no good reason for denying in principle that a state may, in appropriate circumstances, undertake a binding obligation by consenting to a resolution of an international organisation. Ratification of a signed treaty is not the only way of assuming binding obligations in international law. In the Advisory Opinion concerning Railway Traffic between Lithuania and Poland (1931), PCIJ, Series A/B, No 42, the PCIJ considered that a resolution of the Council of the League of Nations was in the nature of an engagement binding upon members. See also Conforti, Hag R, 142 (1974), ii, at p 271ff; cf Arrangio-Ruiz, Hag R, 137 (1972), iii, pp 486–95.

See § 463; Fauchille, §§ 815–815(6), 822(2); McNair, Treaties, pp 30–31; Verzijl, International Law in Historical Perspective, 6 (1973), pp 181–201. For examples of various treaty texts making provision for the language versions of the treaty see Handbook of Final Clauses, UN Doc ST/LEG/6 (1957), pp 164–8 (this collection of final clauses has been up-dated by successive annexes to Multilateral Treaties in respect of which the Secretary-General performs Depositary Functions, published periodically in the series ST/LEG/SERIES E, most recently E/8 (1990)), and Blix and Emerson, The Treaty-Maker’s Handbook (1973), pp 254–7. As to problems of interpretation which can arise with treaties in two or more languages, see § 634.

It may happen that a treaty is negotiated in one language and subsequently other authentic language texts are prepared. This may happen after the treaty has entered into force, or in the period between its adoption and being opened for signature. See, eg respectively, the Protocol of 1968 (TS No 115 (1969)) whereby French and Spanish language texts were added as authentic texts to the Convention on Civil Aviation 1944 (UNTS, 15, p 295), on which see Fitzgerald, AJ, 64 (1970), pp 364–71; and paras 2 and 3 of the Final Act of the Convention on the Regulation of Antarctic Mineral Resource Activities 1988 (ILM, 27 (1988), pp 859, 865); see also § 634, n 1. The task of preparing texts in the various languages usually falls to the Drafting Committee of a Conference, as in the last-mentioned example, and as in respect of the Convention on the Law of the Sea 1982, on the role of the Drafting Committee for which see Treves, AFDI, 27 (1981), pp 65–85; Nelson, BY, 57 (1986), pp 169–99. As to the legal irrelevance of an additional but non-authentic text, see Flegenheimer Claim, ILR, 25 (1958-I), pp 91, 156.

ICJ Rep (1961), at p 31. The Court was concerned with the form of a declaration accepting the court’s jurisdiction. However, where a decision is taken within an institutional framework established by treaty, the fact that it was the result of negotiation between the states concerned within the organ empowered to adopt the decision does not give it the character of an international agreement albeit in unusual form: Case No 38/69, Commission of the European Communities v Italy [1970] ECR 47, 56.

See § 577.

By derivation, protocol (from the Low Latin and late Greek) means the ‘first-glued’ to a book, ie the flyleaf or register of the contents of a bundle of documents, and eventually the document itself. On the present use of the term see Hyde, ii, § 514; Satow, §§ 651–71; Vaughan Williams, Hag R (1923), iii, p 256; Genet, iii, pp 530–34; Starke, Studies in International Law (1965), pp 67–80; Satow, pp 243–5.

A protocol will usually be an instrument supplementary to a principal treaty, and may be concluded at the same time as the treaty, or later. Protocols are often declared to be an integral part of the treaty. While usually dependent upon the treaty, so that if it is terminated so too is the protocol, a protocol may be capable of continuing in force after the principal treaty has come to an end.

See McNair, Treaties, pp 22–5; Brandon, AJ, 47 (1953), pp 49–69; Myers, AJ, 51 (1957), pp 574–605; Le Roy and Saidenberg, Nomenclature des traités et actes diplomatiques de la France en 1964 (1967); Genet, iii, pp 476–538. For a consideration of various forms of international agreements, and their varying degrees of legal effectiveness, see Baxter, ICLQ, 29 (1980), pp 549–66. As to concordats, see § 101, n 3.

The designation alone may be one element amongst others to be taken into account in considering whether the parties had, as a matter of substance, come to an arrangement which fulfilled the requirements for a treaty. For an instrument referred to as an ‘agreement’ (the UK-Ireland Sunningdale Agreement) being held to be only a communiqué containing statements of policy rather than an agreement or treaty see Boland v An Taoiseach [1974] IR 338.

The distinction may be significant in municipal law, as with the distinction made in the USA between treaties, which can only be ratified by the President with the consent of the Senate, and agreements, which do not require such consent, see Moore, v, § 752; Crandall, Treaties: their Making and Enforcement (1916), §§ 56–61; and below, § 636, n 4. See also Ministère Public v Simon (1974), ILR, 77, p 387. As regards the assertion that only such compacts require ratification as bear the title ‘treaties’ or ‘conventions’, see § 603.

ICJ Rep (1962), at p 331.

In the Aegean Sea Continental Shelf Case (Jurisdiction), ICJ Rep (1978), p 1, the ICJ observed ‘that it knows of no rule of international law which might preclude a joint communiqué from constituting an international agreement’ (at p 39): the communiqué in question had been neither signed nor initialled. The Court concluded that, in the light of its terms and the context in which it was agreed and issued, it did not have the binding effect contended for (at pp 43–4). See Merrills, LQR, 95 (1979), pp 340, 343–5. As to the so-called ‘Gleneagles Agreement’ of 1977 (concerning sporting links with South Africa), which was also in the form of a communiqué, see § 439, n 17. See also the so-called ‘Luxembourg Communiqué (or, Accords)’ of 1966, which concerned voting practices in the Council of the European Communities: as to its legal effect, see Lasok and Bridge, Law and Institutions of the European Communities (4th ed, 1987), pp 205–8. See also Scindia Steam Navigation Co Ltd v Union of India (1961), ILR, 53, pp 112, 124–8. As to obligations arising from an agreed resolution see Case No 141/78, French Republic v United Kingdom [1979] ECR 2923. See also § 582, n 23, as to unilateral but parallel statements.

In this respect it may be doubted whether the ILC was wholly correct in stating in Commentary (Treaties), Art 2, para (2) (YBILC (1966), ii, p 188) that, inter alia, a memorandum of understanding was ‘undoubtedly’ an international agreement subject to the law of treaties. An ‘understanding’ may well be an understanding and no more, intended and so worded as to be something less than an agreement creating legal rights and obligations. Taken in its context the Commentary was primarily making the point that there are many kinds of single, though informal, instruments which, while not ‘treaties’ in a narrow sense, are nevertheless instruments to which the law of treaties can apply (and often does), thus supporting the ILC’s decision to use the term ‘treaties’ in a generic sense. See generally on memoranda of understanding, Aust, ICLQ, 35 (1986), pp 787–812. See also AJ, 81 (1987), pp 939–40, as to the non-binding status of the understandings reached by President Kennedy and Chairman Kruschev, by which the Cuban missile crisis of 1962 was resolved. See also Opinion 1/75 [1975] ECR 1355 holding an understanding concluded within the OECD to be, given its substantive content, an agreement. See also § 582, n 21. Note also § 582, n 19, and § 577, nn 21–4, as to undertakings leaving so great an element of discretion as to make the existence of legal rights and obligations questionable. That an instrument does not constitute a treaty does not mean that it does not have legal effect: see Interpretation of the American Declaration of the Rights and Duties of Man, ILM, 29 (1990), pp 379, 390–1.

Thus the originating note will often set out a proposal, invite the other state to agree to it, and suggest that if it does agree that state’s reply to that effect and the originating note should together constitute an agreement; the note in reply will agree with the proposals and confirm that the two notes constitute an agreement.

10  See on the subject Weinstein, BY, 29 (1952), pp 205–26. See also Fitzmaurice, BY, 15 (1934), p 120. At least one-third of the treaties registered with the UN are in the form of exchanges of notes.

The title of a treaty may suggest ‘the spirit and intention of the Treaty as a whole’: Beagle Channel Arbitration (1977), ILR, 52, pp 93, 131.

Paul You, Le Préamble des Traités Internationaux (1941), and RI (Geneva), 20 (1942), pp 25–45. See also the Asylum Case, ICJ Rep (1950), p 282.

The preamble forms part of the context of a treaty for purposes of interpreting its terms: see § 632, para (3).

3a  See Handbook of Final Clauses, UN Doc ST/LEG/6 (1957) (this collection of final clauses has been up-dated by successive Annexes to Multilateral Treaties in respect of which the Secretary-General performs Depositary Functions, published periodically in the series ST/LEG/SERIES E, most recently E/8 (1990)).

The matter is treated with all details by Pradier-Fodéré, ii, §§ 1086–99.

See § 663.

It is common for states to provide expressly that some associated instruments are integral parts of a treaty, as in the case of protocols (see § 586, n 2) and agreed minutes (see, eg in Art XIX of the 1984 Fisheries Agreement between the European Communities and the USA: ECTS No 3 (1985)). However, cf the decision adopted by EC Ministers on the occasion of the signing of the Single European Act 1986 was distinct from that Act and did not itself constitute a treaty: Parliamentary Debates (Commons), vol 99, cols 433, 645 (written answers, 16 and 20 June 1986).

ICJ Rep (1952), pp 41–3. The main reason of the decision of the Court was the fact that in the instruments of ratification and registration the Treaty and the Declaration were treated as a whole. But see on the subject the Dissenting Opinions of Judges McNair (at p 60) and Basdevant (at p 70); and for comment see Fitzmaurice, BY, 33 (1957), pp 255–66.