Treaty Interpretation by Relying Upon Other International Legal Norms

Abstract

Finding a basis on which a meaning may be associated with the legal text at hand is of key importance when interpreting international treaties. Other pieces of international rule-making may constitute such a basis, and – under certain conditions – they may be relied on by international courts in the course of interpreting and construing a treaty provision. This technique may strengthen the systemic nature of international law, but increases uncertainty. With special regard to Article 31(3)( c) of the 1969 Vienna Convention, the article tries to identify the most significant problems associated with the interpretation of international treaties based on the rules of other international instruments. Some of them are reviewed in more detail, eg. the boundary between interpretation and "application" of law; or how much the number of State Parties to a treaty or international agreement sets limits to using this method of legal interpretation.

Keywords: treaties; interpretation; application of law; fragmentation of international law; limited jurisdiction; International Court of Justice; Article 31(3)( c) of the 1969 Vienna Convention

JEL Classification: K33