7. The law of treaties

Abstract

This chapter describes the law of treaties. As defined in Article 2(2) of the Vienna Convention on the Law of Treaties (VCLT), a treaty can be embodied in a single instrument, or in two or more related instruments. It is a written agreement; between international legal subjects; and governed by international law. In short, a treaty must be written in order to fall under the scope of the VCLT. Though this does not mean that oral agreements have no effect in international law, it does mean that the law of treaties embodied in the VCLT does not govern oral agreements. While States are the most active actors entering into treaty relations, international organizations may also enter into treaties, whether between them or with a State. Ultimately, because a treaty’s purpose is to create binding international legal obligations, the law of treaties applies to agreements governed by international law.