When former Chilean dictator Augusto Pinochet was arrested in London at the request of a Spanish judge, the world's attention was focused for the first time on the idea of universal jurisdiction. Universal jurisdiction stands for the principle that atrocities such as genocide, torture, and war crimes are so heinous and so universally abhorred that any state is entitled to prosecute these crimes in its national courts regardless where they were committed or the nationality of the perpetrators or the victims. In 2001, two Rwandan nuns were convicted in a Belgian court for atrocities committed in Rwanda against Rwandans. Serbs have been prosecuted in German courts, and a court in Senegal asserted universal jurisdiction over the former dictator of Chad, Hissene Habre. Universal jurisdiction is becoming a potent instrument of international law, but it is poorly understood by legal experts and remains a mystery to most public officials and citizens.