Global Politics

by Andrew Heywood

Chapter 14 Notes: International Law

  • How does international law differ from domestic law?
  • What are the sources of international law?
  • Why is international law obeyed?
  • How and why has international law changed in recent years?
  • What are the implications of holding individuals responsible for violating international humanitarian law?

International law is an unusual phenomenon. As traditionally understood, law consists of a set of compulsory and enforceable rules; it reflects the will of a sovereign power. And yet, no central authority exists in international politics that is capable of enforcing rules, legal or otherwise. Some, therefore, dismiss the very idea of international law. Nevertheless, international law has greater substance and significance than first appearances suggest. In particular, more often than not, international law is obeyed and respected, meaning that it provides an important – and, indeed, an increasingly important – framework within which states and other international actors interact. However, what is the nature of international law, and where does it come from? Also, if international law is rarely enforceable in a conventional sense, why do states comply with it? The growing significance of international law is reflected in changes in its scope, purpose and operation since the early twentieth century. These include a shift from 'international' law, which merely determines relations between and among states, to 'world' or 'supranational' law, which treats individuals, groups and private organizations also as subjects of international law. This has drawn international law into the controversial area of humanitarian standard-setting, especially in relation to the so-called 'laws of war'. It has also, particularly since the end of the Cold War, led to attempts to make political and military leaders at all levels personally responsible for human rights violations through a framework of international criminal tribunals and courts. To what extent has 'international' law been transformed into 'world' law? How have the laws of war been developed into international humanitarian law? And have international criminal tribunals and courts proved to be an effective way of upholding order and global justice?

  • International law is law that governs states and other international actors, although it is widely considered to be 'soft' law, because it cannot, in most circumstances, be enforced. The two most important sources of international law are treaties and international custom. In the former, legal obligations are clearly rooted in consent, while in the latter obligations arise from long-established practices and moral norms.
  • International law is largely obeyed because states calculate that in the long run abiding by laws will bring them benefit or reduce harm. Other reasons for obedience include a fear of disorder, a fear of isolation, a fear, in some cases, of punishment and the wider belief that international law is rightful and morally binding.
  • In its classical tradition, international law has been firmly state-centric, being based on the cornerstone principle of state sovereignty However, this conception has increasingly been challenged by a 'constitutionalist' conception of international law, sometimes called 'supranational' law or 'world' law, whose scope includes the maintenance of at least minimum standards of global justice.
  • One of the clearest examples of the shift from 'international' law to 'world' law has been the evolution of the laws of war into a body of international humanitarian law. This has largely happened through the development of the idea of war crimes, which allows individuals to be held to be criminally responsible for violations of the customs of war, and through the notion of crimes against humanity.
  • The end of the Cold War allowed international humanitarian law to be implemented more widely through international tribunals and courts. This happened through ad hoc tribunals set up to examine reports of atrocities carried out in former Yugoslavia and Rwanda in particular, but the most significant development was the establishment of the International Criminal Court, which came into operation in 2002. However, the Court has sometimes been seen as a threat to international order and peace.