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Last update: June 22, 2023

Summaries of the Work of the International Law Commission

Reservations to multilateral conventions

See also: Analytical Guide | Texts and Instruments

The question of reservations to multilateral conventions arose out of difficulties encountered by the Secretary-General in his capacity as depositary of the Convention on the Prevention and Punishment of the Crime of Genocide, which had been adopted by the General Assembly on 9 December 1948.1 The Secretary-General, as depositary of multilateral conventions, had substantially followed the practice of the League of Nations. Under this practice, in the absence of stipulations in a convention regarding the procedure to be followed in the making and accepting of reservations, the Secretary-General accepted in definitive deposit an instrument of ratification or accession offered with a reservation only after it had been ascertained that there was no objection on the part of any of the other States directly concerned. This practice, however, was contested by some Member States and, in 1950, the Secretary-General asked the General Assembly for directions on the procedure he should follow.2 The General Assembly, by resolution 478 (V) of 16 November 1950, requested an advisory opinion from the International Court of Justice on reservations to the Genocide Convention. The Assembly also invited the Commission, in the course of its work on the codification of the law of treaties, to study the question of reservations to multilateral conventions in general, both from the point of view of codification and from that of the progressive development of international law, and to report to the Assembly at its sixth session, in 1951.

In pursuance of this resolution, the Commission, in the course of its third session, in 1951, gave priority to a study of the question of reservations to multilateral conventions.3 It had before it a “Report on Reservations to Multilateral Conventions”,4 submitted by the Special Rapporteur on the topic of the law of treaties, as well as two memoranda, submitted by two other members of the Commission.5 In its report to the Assembly, the Commission stated that the criterion of compatibility of a reservation with the object and purpose of a convention — applied by the International Court of Justice in its advisory opinion on reservations to the Genocide Convention6 — would not be suitable for application to multilateral conventions in general; while no single rule uniformly applied could be wholly satisfactory, a rule suitable for application in the majority of cases could be found in the practice theretofore followed by the Secretary-General, with some modifications.7

The General Assembly, in resolution 598 (VI) of 12 January 1952, endorsed the Commission’s recommendation that clauses on reservations should be inserted in future conventions; stated that the Court’s advisory opinion should be followed in regard to the Genocide Convention; and asked the Secretary-General, in respect of future United Nations conventions, to act as depositary for documents containing reservations or objections thereto without passing on the legal effect of such documents. The documents were to be communicated to all States concerned, to which it would be left to draw the legal consequences. In 1959, the General Assembly, in resolution 1452 (XIV) of 7 December 1959, asked the Secretary-General to follow the same practice with respect to United Nations conventions concluded before, as well as after, the Assembly’s resolution of 1952.

The Commission returned again to the subject in the course of its preparation of draft articles on the law of treaties and the question of treaties concluded between States and international organizations or between two or more international organizations. Articles 19 to 23 of the 1969 Vienna Convention on the Law of Treaties and of the 1986 Vienna Convention on the Law of Treaties between States and International Organizations or between International Organizations deal with reservations to treaties. The Commission also took up the subject in the context of its work on the topic of reservations to treaties.

1 United Nations, Treaty Series, vol. 78, p. 277.

2 See Official Records of the General Assembly, Fifth Session, Annexes, agenda item 56, document A/1372. (see Analytical Guide)

3 At this session, the Commission recalled its preliminary discussion of the question at its second session, in 1950, on the basis of the report of the Special Rapporteur on the topic of the law of treaties (document A/CN.4/23).

4 See Yearbook … 1951, vol. II, document A/CN.4/41.

5 See Yearbook … 1951, vol. II, documents A/CN.4/L.9 and A/CN.4/L.14.

6 The Court declared that a State which has made and maintained a reservation which has been objected to by one or more of the parties to the Convention but not by others, can be regarded as a party to the Convention if the reservation is compatible with the object and purpose of the Convention; otherwise that State cannot be regarded as a party. International Court of Justice, Reports of Judgments, Advisory Opinions and Orders, 1951, p. 29.

7 See Yearbook … 1951, vol. II, document A/1858, paras. 12–34. (see Analytical Guide)