The Theory and Reality of the Sources of International Law

Abstract

The classic starting point for identifying the sources of international law is Article 38 of the Statute of the International Court of Justice. Article 38 famously refers to three sources: treaties, customary international law, and general principles of law; as well as two subsidiary means for determining rules of law, namely judicial decisions and the teachings of publicists. However, Article 38 does not adequately reflect how the doctrine of sources operates in practice because it omits important sources of international law while misrepresenting the nature and weight of others. To appreciate how the doctrine of sources operates in practice, international lawyers need to understand how international law is created through a dialogue among states, state-empowered entities and non-state actors. States are important actors in this process, but they are not the only actors. It is only by understanding this process of dialogue that one can develop a full understanding of the theory – and reality – of the sources of international law.

Keywords: international law, sources, treaties, custom, customary international law, CIL, general principles, traditional, modern, theory, reality, states, state-empowered entities, non-state actors