In this volume, the third in his trilogy on the philosophical and legal aspects of war and conflict, Larry May locates a normative grounding for the crime of aggression - the only one of the three crimes charged at Nuremberg that is not currently being prosecuted - that is similar to that for crimes against humanity and war crimes. He considers cases from the Nuremberg trials, philosophical debates in the Just War tradition, and more recent debates about the International Criminal Court, as well as the hard cases of humanitarian intervention and terrorist aggression. His thesis refutes the traditional understanding of aggression. At Nuremberg, crimes against humanity charges were only pursued if the defendant also engaged in the crime of aggression. May argues for a reversal of this position, contending that aggression charges should be pursued only if the defendant’s acts involve serious human rights violations.