The role of subsequent practice of states in the interpretation of treaties: The judgment of the International Court of Justice in the Application of the Interim Accord of 13 September 1995 Case

Under the Vienna Convention on the law of treaties, when interpreting a treaty, there shall be taken into account any subsequent practice in the application of the treaty which establishes the agreement of the Parties regarding its interpretation. A large number of treaties have reached a certain age and they need to be adapted to the current situation. One way to this end is to interpret the treaties by means of the subsequent practice of the parties. Over the recent years, International Law Commission has paid particular attention to this topic and various international tribunals have resorted to the subsequent practice in order to interpret the treaties. In its Judgment of 5 December of 2011 in the “Application of the Interim Accord of 13 September 1995” case, the International Court of Justice addressed the question of subsequent practice and its role in the interpretation of treaties. The present article examines the compatibility of the above judgment with both the 1969 Vienna Convention and the previous case-law of the Court.