MAKING LAW BY BREAKING THE LAW: HOW CUSTOMARY INTERNATIONAL LAW CAN BE SHAPED BY LAW-BREAKING, AND A CASE STUDY ON HUMANITARIAN INTERVENTION

Abstract

This paper addresses how violations of customary international law can, in certain circumstances, lead to the formation of new customary rules that either modify or extinguish the existing violated norm. It posits that this is a phenomenon which does occur under international law, but one that is limited by multiple factors. Four factors – inherent resistance, the nature of the existing norm being violated, evidential difficulties, and the political standing of the law-breaking states – are discussed. Each restrict the extent to which violations of customary international law can result in new customary rules. Two key conclusions are drawn. Firstly, proving that a new customary norm has emerged from law-breaking is more difficult than proving that a customary norm has emerged from practice that does not involve law-breaking. States need compelling reasons to break the law, and these reasons must cause a significant number of states to defect from the original rule in order to satisfy the requirements of custom formation. There must be substantial evidence of such defection in order to support claims that law-breaking has resulted in new rules of custom. Secondly, fundamental customary norms are less susceptible to modification or extinguishment. Where an existing norm is regarded by virtually the entire international community as fundamental due to the values or rights that it enshrines, instances of law-breaking are unlikely to result in a new norm that modifies or extinguishes the existing fundamental norm.

The posited thesis will then be applied to instances of humanitarian intervention that have occurrred. It will be demonstrated that no customary rule of humanitarian intervention has emerged, due to two key factors. Firstly, the norm being violated - the prohibition on the use of force - is of a fundamental nature and is hence more resistant to change. Secondly, whilst states have, on occassion, violated the prohibition on the use of force, there is insufficient evidence of positive state practice and opinio juris supporting a would-be norm of humanitarian intervention. Such sparse evidence cannot support the birth of a new customary exception to the prohibition on the use of force.