CYIL vol. 9 (2018)

PAVEL ŠTURMA CYIL 9 ȍ2018Ȏ The adopted approach corresponds well with the classical CIL created by a general practice accepted as law. It is less adapted to the new, revolutionary custom, emerging mostly in and by the practice of international organizations. 2.2 Subsequent agreements and subsequent practice in relation to the interpretation of treaties The other topic concluded by the ILC on the second reading concerns the role played by subsequent agreements and subsequent practice in the interpretation of treaties. In 2018, the Commission had before it the fifth report of the Special Rapporteur Georg Nolte, 25 as well as comments and observations received from the Governments. 26 As a result of its consideration of the topic, the Commission adopted on the second reading a set of 13 draft conclusions, together with commentaries. The conclusions are based on the Vienna Convention on the Law of Treaties (1969). Following conclusion 1 (on scope), conclusion 2 (General rule and means of treaty interpretation) situates subsequent agreements and subsequent practice as a means of treaty interpretation within the framework of the rules on the interpretation of treaties in articles 31 and 32 of the 1969 Vienna Convention. 27 This conclusion basically highlights those rules and the interrelationship between articles 31 and 32. Conclusion 3 indicates that subsequent agreements and subsequent practice under article 31, paragraph 3 (a) and (b), of the Vienna Convention are authentic means of interpretation. Conclusion 4 provides, in paragraphs 1 to 3, a definition of the three different means of treaty interpretation. A subsequent agreement under article 31, para. 3 (a), is “an agreement between the parties, reached after the conclusion of a treaty, regarding the interpretation of the treaty or the application of its provisions.” A subsequent practice under article 31, para. 3 (b), consists of conduct in the application of a treaty, after its conclusion, which establishes the agreement of the parties regarding the interpretation of the treaty. A subsequent practice as a supplementary means of interpretation under article 32 “consists of conduct by one or more parties in the application of the treaty, after its conclusion.” 28 Conclusion 5 clarifies that subsequent practice under articles 31 and 32 “may consist of any conduct of a party in the application of a treaty, whether in the exercise of its executive, legislative, judicial, or other functions” (para. 1). 29 This also implies, as stated in para. 2, that other conduct, including that by non-State actors, does not constitute subsequent practice under articles 31 and 32. However, such conduct, including reports by international organizations or “social practice” sometimes referred to by the European Court of Human Rights, may be relevant when assessing the subsequent practice of treaty parties. 30 Conclusion 6 then deals with the identification of subsequent agreements and subsequent practice. 31 It requires a determination whether the parties, by an agreement or by practice, have taken a position regarding the interpretation of the treaty. According to para. 2, subsequent agreements and subsequent practice under article 31 (3) may take a variety of

25 See doc. A/CN.4/715 (2018). 26 See doc. A/CN.4/712 and Add.1. 27 See doc. A/CN.4/L.917/Add.1 (2018), p. 3.

28 Ibid., p. 13. 29 Ibid., p. 24. 30 Ibid., pp. 27-29. 31 Ibid., p. 30.

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