3 The Law of Treaties

Abstract

This chapter discusses how peremptory norms/jus cogens entered positive law with the Vienna treaties on treaties. Jus cogens was first included in the work of the International Law Commission (ILC) with the Third Report of G.G. Fitzmaurice, Special Rapporteur on the Law of Treaties, under the heading ‘legality of the object’. The first two special rapporteurs on the law of treaties supported the notion of peremptory norms in international law. During ILC work on the law of treaties, however, most of the members joined the ILC’s fourth special rapporteur on treaty law, Sir Humphrey Waldock, who sought to reconcile jus cogens with the doctrine of positivism. They spent little time speculating on the origin of jus cogens. The final ILC draft on the law of treaties was produced by Waldock. The work of the ILC on the law of treaties was based essentially on the notion of barring illegal agreements as a general principle of law. The chapter then provides a definition of jus cogens norms.