Article 31(3). (A) And (B) Of The Vienna Convention And The Kasikili/Sedudu Island Case

Abstract

The International Court of Justice's judgment in the Kasikili/Sedudu case successfully brought to an end a boundary in dispute between the parties. It achieved this by introducing a method by which reliance was placed on subsequent practice of the parties which did not, as required by the rules of interpretation set out in VCLT Article 31(3)(a) and (b), result in an agreement of the parties as to the meaning of the disputed words in the treaty. Further, in following this method, it made little attempt to enquire whether the customary rules of interpretation at the time of the conclusion of the treaty were the same or different from those set out in Article 31 nor, if such customary rules permitted reference to the subsequent practice of the parties, whether such practice was admissible solely within a restricted period after the conclusion of the treaty. Keywords: Kasikili/sedudu Island ; Vienna Convention