Introduction to the law of treaties Keiichiro Okimoto Associate Legal Officer Treaty Section, Office of Legal Affairs 16 November 2011

1. Outline  Overview of the life of treaties  Review of key concepts of the law of treaties at different stages

2. Brief overview  Consolidated Treaty Series: Treaties from 1648 to 1918  League of Nations Treaty Series: Treaties from 1919 to 1945  United Nations Treaty Series: Treaties from 1945, more than 67,000 treaties as at August 2011  Long history  Widespread means in international relations  States + international organizations

3. Treaties / customary international law Customary international law  Unwritten  Formed through State practice and opinio juris  Binding on all States and international organizations  No reservations can be made  No denunciation / withdrawal Treaties  Written  Adopted at a bilateral meeting or a multilateral forum  Binding upon consent to be bound  Reservations under certain conditions  Denunciation /withdrawal under certain conditions

4. Law of treaties/Vienna Conventions 1969 and 1986  Law of treaties: international law regulating the procedural aspects of treaties 1966 Vienna Convention  1949: International Law Commission includes law of treaties as a topic for study  1966: General Assembly calls for a diplomatic conference  1969: Vienna Convention on the Law of Treaties (VCLT) adopted  Today, 111 States parties (November 2011) 1986 Vienna Convention  1986 Vienna Convention on the Law of Treaties between States and International Organizations or between International Organizations

5. Definition of treaty VCLT Art. 2(1)(a)  Concluded between  States  States and international organisations  International organisations  Written form  Governed by international law  Single instrument / two or more instruments  Whatever the designation

6. Types of treaties  Bilateral treaties:  Two States  Two international organisations  A state/an international organisation  Multilateral treaties:  Between more than two States  Limited participation  Open

7. Birth of treaties  Proposal  Negotiation  Adoption of the text (VCLT Art. 9)  Authentication of the text (VCLT Art. 10)

8. From adoption to entry into force Signature/consent to be bound  Opening for signature (limited participation v. open, limited period v. indefinite)  Signature + ratification/acceptance/approval  Accession  Definitive signature  Obligation to refrain from acts that would defeat the object and purpose of the treaty prior to its entry into force Other possible treaty actions  Reservations (under certain conditions)  Objections to reservations  Declarations (mandatory/optional/interpretative)  Corrections

9. Methods of entry into force  Treaty becomes formally binding on the parties  Provisions of the treaty often specify the method Bilateral treaties  Definitive signature by both parties  Notification of completion of the internal procedure  Exchange of instruments of ratification Multilateral treaties  Consent to be bound by a specific number of States  Consent to be bound by a specific category of States  After lapse of certain period  If the method is not specified in the treaty, consent to be bound by all negotiating States (VCLT Art. 24)

10. After the entry into force Signature/consent to be bound  Signature  Ratification/acceptance/approval  Accession Other possible treaty actions  Reservations (under certain conditions)  Objections to reservations  Declarations (mandatory/optional/interpretative)  Amendments  Termination, suspension, invalidity, withdrawal/denunciation  Territorial application/exclusion  Extension  Succession (1978 Vienna Convention on succession of States in respect of treaties )

11. Signatory State, contracting State, party  Signatory State: State that has signed but not consented to be bound by the treaty  Party:  State that has consented to be bound  Treaty itself is in force  Treaty is in force for that State  Contracting State:  State that has consented to be bound  Regardless of whether the treaty has entered into force

12. Interpretation of treaties General principle (VCLT Art. 31 (1))  Good faith  Ordinary meaning  In the context of the treaty  In the light of its object and purpose “Context” (VCLT Art. 31 (2))  Text, including preamble/annexes  Agreements and instruments relating to the treaty Other means (VCLT Arts 31 (3), 32)  Subsequent agreements  Subsequent practice  Relevant rules of international law  Supplementary means, including preparatory work

13. Depositary (VCLT Arts )  For multilateral treaties  State or international organisation (or its chief administrative officer) General principles  International in character  Impartiality Functions  Keep custody of the original text  Prepare/transmit certified true copies  Receive signatures  Examine signatures, instruments, notifications, communications  Inform treaty actions  Inform that the requirements for entry into force are met  Register treaties with the Secretariat of the United Nations  Other functions specified by the treaty

14. Registration and publication UN Charter Art. 102, VCLT Art. 80  All treaties/international agreements  After their entry into force  Submit to the Secretariat of the United Nations for registration and publication

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