Why Have We Criminalized Aggressive War?

Abstract

On the dominant view, accepted by both defenders and critics of the criminalization of aggression, the criminal wrong of aggressive war is inflicted on the attacked state. This view is mistaken. It is true that whether a war is criminally aggressive is determined ordinarily by whether it involves a particular form of inter-state wrong. However, that is not why such wars are criminal. Aggressive war is a crime because it entails killing without justification. Five reasons explain why this is so. First, banning aggression restricted states from using force to protect their core sovereign rights, including even their rights of political independence and territorial integrity. Those core states’ rights cannot make sense of the move to ban aggression. Second, what distinguishes aggression from any other sovereignty violation — what makes it criminal, when no other sovereignty violation is — is that it involves killing without justification. Third, the unjustified killing account makes sense of aggression’s standing alongside genocide, war crimes, and crimes against humanity. The traditional notion that aggression is a crime against sovereignty instead isolates aggression as the inexplicably odd crime out. Fourth, the public reasons for restricting jus ad bellum rights in the early twentieth century focused not on infringements of states’ rights but on the infliction of death without justification. Finally, the importance of wrongful killing to the criminalization of aggression was apparent at the post-World War II tribunals at Nuremberg and Tokyo. Understanding the crime in this way matters doctrinally. It clarifies the boundaries of the crime, resolving hard cases like unilateral humanitarian intervention and bloodless invasion. It also has implications for the legal rights of soldiers involved on either side of such wars.

Keywords: Aggression, International Criminal Law, Just War Theory, Nuremberg, ICC