When Actions Speak Louder Than Words: The Relevance of Subsequent Party Conduct to Treaty Interpretation

Abstract

The way in which a treaty is implemented by the parties can provide important evidence as to its interpretation. This article proposes that subsequent party conduct is primarily relevant to the exercise of treaty interpretation where that conduct demonstrates the parties' agreement to the interpretation of the treaty's terms, and the agreed interpretation comes within the four corners of the treaty text. Otherwise, subsequent party conduct may produce other legal consequences such as through the operation of estoppel.

Keywords: treaty interpretation, subsequent practice, subsequent agreement, Vienna Convention, Article 31(3)

JEL Classification: K33