What rules of international law make the individual, even a Head of State, responsible for perpetrating serious human rights violations, such as war crimes, torture or genocide? This question is becoming more critical in our increasingly interdependent world, and the recent invasion of Kuwait and the brutalization of its people by Iraqi leader Saddam Hussein has heated up the debate even further. The author argues that a new rule of international law stipulating individual responsibility for all serious human rights violations is currently emerging. To show how this is coming about, he explores relevant norms in classic laws of war, international humanitarian law and modern international human rights law and surveys patterns in their implementation. He then takes account of codification efforts of the International Law Commission, the changing position of the individual in international law, and other important developments in the context of general international law as an evolving system.