An Introduction to International Relations

Introduction

This chapter discusses the role of international law in world politics. It begins with a discussion of the content of international law, explaining the sources of law and how we identify them. Where does law come from, and where are legal problems solved at the international level? It then addresses the question of why the study of international law is foundational to the study of international relations. The chapter offers two answers to this question, which it explores in turn. First, one of the central debates in international relations theory – whether or not states pursue their national interest unchecked by rules, is at its heart a debate about international law. Realist theories of international relations have dismissed international law as having no real influence on state behaviour, arguing instead that ‘might equals right’: states will follow the law when it is in their interests, and will disregard it in all other cases. Other theories of international relations dispute this position, and argue that law is at the very least central to international activity, if not foundational to it. Second, the study of international law is also important because law is at the heart of many international disputes today. The chapter concludes by considering two examples of ‘law in action’: the legal decision regarding Chinese activities in the South China Sea and the contemporary debate over membership in the International Criminal Court.

What is international law?

When we speak of international law, to what are referring? Hedley Bull (1977: 122) defines international law as ‘a body of rules which binds states and other agents in world politics in their relations with one another and is considered to have the status of law’. When international law makes the news, it is often because of a major political crisis or event, such as the use of chemical weapons, the presence of war crimes or the invasion of one state by another without UN authorisation. However, as Bull's definition reveals, international law governs almost every facet of international life, from the mundane to the complex.