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This new edition of a textbook first published in 2000 provides a comprehensive account of the law of treaties from the viewpoint of two experienced practitioners. It draws on the combined experience of Anthony Aust, the original author, and Jeremy Hill, until recently Legal Counsellor in the Foreign, Commonwealth and Development Office, London. The book provides a wealth of examples of the problems experienced with treaties on a daily basis. The authors explore numerous precedents from treaties and other related documents, such as non-legally binding instruments. Using clear and accessible language, the authors cover the full extent of treaty law, with both practitioners and students in mind. Modern Treaty Law and Practice is essential reading for officials in governments and international organisations, lawyers practising in international law, and teachers and students of law, political science, international relations and diplomacy who have an interest in treaties.
The chapter analyses each element of the definition of a treaty in the Vienna Convention on the Law of Treaties 1969: an international agreement, concluded between states, in written form, governed by international law, either in a single instrument or in two or more related instruments, whatever its particular designation. Agreements in simplified form such as an exchange of notes or an exchange of letters can also be treaties. The chapter examines the criteria which international courts and tribunals have applied in determining whether other instruments such as agreed minutes might constitute treaties. Relevant factors include: form and designation, terminology, subject matter, terms, context, intent, level of negotiator, definite or conditional terms, clarity, subsequent practice, and registration with the UN. Examples of electronic signature are noted, although state practice is sparse. A treaty should be distinguished from a non-legally binding instrument, such as a memorandum of understanding, although some states use the title ‘Memorandum of Understanding’ also for treaties with a certain subject matter. Unilateral declarations are not treaties but may in some circumstances have binding legal effects. Treaties have a wide variety of titles, including Protocol, but the title does not itself determine whether an instrument is a treaty.
Although the Vienna Convention on the Law of Treaties devotes nine articles to invalidity of treaties, cases rarely arise in practice. Circumstances covered by the Convention include violation of internal law, error, fraud, corruption, coercion and violation of a peremptory norm of international law (jus cogens). Article 46 of the Convention covers the first of these, providing that a state may not invoke the fact that its consent to be bound has been expressed in violation of its internal law unless that violation was manifest and concerned a rule of fundamental importance. The chapter examines the meaning of the key terms of this provision and possible cases in which this might arise. In the context of coercion, the chapter looks at treaties which might be concluded by the threat or use of force, peace treaties and unequal treaties. The scope of peremptory norms (jus cogens) is also discussed, together with the consequences of invalidity.
Like contracts in ordinary life, treaties have always been an indispensable tool of diplomacy. They date from even before the classical period of Greece, the Egyptian and Hittite kings having concluded a treaty in about 1259 BCE.2 After 1815, so many treaties were adopted that Canute-like words of caution were voiced. By 1914, there were already perhaps over 8,000 treaties in force. With the establishment of the League of Nations, the rate of treaty making increased dramatically.3 Up to July 1944, the League registered another 4,822 treaties, to which should be added those concluded between non-members of the League.
This chapter examines how a state becomes a party to a treaty, including signature, initialling and ratification, where applicable. Whether a state can participate in a multilateral treaty depends on the terms of the treaty. The practice of the Council of Europe is examined. Signature may express consent to be bound but often signature will be subject to ratification. Ratification is the international act whereby a state establishes on the international plane its consent to be bound. It is to be distinguished from the domestic process which enables a state to ratify. Advice is given on the form and content of an instrument of ratification. A state may also consent to be bound by acceptance, approval or accession. Accession is primarily the means by which a state may become a party if it is unable to sign the treaty. The chapter also examines rights and obligations prior to entry into force, the possibility of withdrawing consent to be bound, and the ways in which treaties might be developed.
The chapter gives advice on how to draft a treaty, an exchange of notes or a non-legally binding instrument. It goes through all the main components of a treaty text, including the name, preamble, main text, final clauses and testimonium. It covers the drafting of provisions concerning signature, ratification, entry into force and provisional application. It highlights the special considerations which apply to an exchange of notes or letters, including the procedures involved. The second part of the chapter gives practical advice on certain basic drafting techniques.
Normally, treaties contain express provision on duration and termination. These can take a variety of forms, including indefinite duration with a right to terminate, or a conditional right to terminate. Various types of clauses are examined, together with the situation where a treaty contains no provision for termination or withdrawal. A treaty may also be terminated by consent or by conclusion of a later treaty. The chapter examines the relationship between treaty provisions and countermeasures, and analyses the right of one or more parties to terminate or suspend a treaty for material breach. It also examines other grounds for termination, including supervening impossibility of performance and fundamental change of circumstances (rebus sic stantibus), the procedure for termination, and special circumstances such as the severance of diplomatic relations or outbreak of hostilities.
Non-legally binding instruments do not constitute treaties but they are widely used by states and international organisations as a form of political commitment. They have various titles, the most common of which is memorandum of understanding, although some states use this title also for treaties with a certain subject matter. In the multilateral context, non-binding instruments are often used for plans of action, guidelines and other forms of standard setting. To ensure that an instrument is non-legally binding, care must be taken in the drafting to evidence that intention, including use of the right terminology. An examination of state practice reveals broadly similar principles. Why do states and international organisations use non-legally binding instruments in preference to treaties? Reasons include confidentiality, lack of formality, and ease of amendment and termination. But there are risks, including possible lack of respect for commitments and lack of care in drafting. Non-legally binding instruments, both bilateral and multilateral instruments, may in some contexts be regarded as a form of soft law. They may also exceptionally give rise to estoppel. Non-legally binding instruments may also be evidence of a state’s decision or policy in the context of judicial review by domestic courts.
This chapter explains the role played by reservations, the application of the rules of the Vienna Convention on the Law of Treaties, and practice in dealing with reservations. It defines reservations and distinguishes them from interpretative declarations and political declarations. It examines whether reservations are permissible or impermissible, including the test whether a reservation is incompatible with the object and purpose of the treaty. It also discusses the rules governing acceptance and objection, the legal effect of reservations, the question whether a prohibited reservation can be severed, and special cases such as human rights treaties, reservations relating to internal law, vague or general reservations, reference to Islamic law, late reservations, and the role of treaty monitoring bodies. It analyses the procedure for making or objecting to reservations or withdrawing them, and the functions of the depositary in relation to reservations.
When a treaty prescribes how disputes can be settled, it usually provides for a preliminary phase involving direct negotiations or consultations. In the case of bilateral agreements, more binding mechanisms tend to be found in agreements with more specific obligations, or those directly affecting individual interests, such as trade. Otherwise, bilateral agreements will often specify that disputes are to be resolved by the diplomatic channel or other avenue of voluntary settlement. Both bilateral and multilateral treaties may provide for conciliation or mediation. The parties may, however, wish to resort to compulsory binding settlement. The two principal features are a prior agreement to submit disputes to a third party, and a provision that the decision of the third party is legally binding on the parties in dispute. Procedures of arbitration and judicial settlement, including the International Court of Justice, are analysed. In respect of remedies, the chapter examines countermeasures and the principles underlying them, sacrosanct obligations and necessity.