Crimes against humanity

The modern concept of crimes against humanity is a product of the scale and horror of the crimes committed in the two world wars as well as a growing consensus in the international community that certain crimes committed within national borders are legitimate subjects of international law and adjudication. Unlike war crimes and genocide, crimes against humanity are not codified in an international convention. Instead, the law of crimes against humanity has primarily developed through the evolution of customary international law. Although the statutes of most international and internationalized tribunals contain definitions of these crimes, there are significant differences among those definitions. Furthermore, the evolution of the definition of crimes against humanity in these international instruments has not been entirely linear: Later definitions are sometimes more expansive and sometimes narrower than their predecessors. As a result, the content of the norm prohibiting crimes against humanity remains subject to greater controversy than the norms prescribing genocide and war crimes. The primary challenge in defining crimes against humanity is to identify the precise elements that distinguish these offenses from crimes subject exclusively to national laws. The contours of the definition not only determine the scope of international jurisdiction, but also give rise to a number of additional important consequences. First, unlike most domestic crimes, crimes against humanity are generally considered outside the purview of statutes of limitations. Second, the immunities that often shield State representatives from criminal responsibility are not available for crimes against humanity, at least when trials are held before international tribunals. Third, although the concept of universal jurisdiction – the theory that certain crimes are subject to the jurisdiction of all States – remains controversial; proponents of universal jurisdiction invariably include crimes against humanity within its scope. This means, for example, that while the crime of murder generally can only be tried in a court with a jurisdictional link to the act, a murder committed as a crime against humanity arguably can be tried in any criminal court in the world. Finally, the prohibition of crimes against humanity is a jus cogens norm of international law, which means that derogation is not permitted under any circumstances. As a result of this status, some authorities assert that States have an international law obligation either to prosecute perpetrators of crimes against humanity or to extradite them to States intending to pursue prosecutions. In light of the very serious legal consequences of designating an offense a crime against humanity as well as the heightened moral condemnation the label entails, the importance of understanding the exact contours of these offenses cannot be underestimated. This chapter provides a brief historical sketch of the evolution of the norm prohibiting crimes against humanity, assesses the current state of the definition with respect to each potential element of the chapeau and some the constitutive crimes, and argues that a normative framework should be adopted to resolve the remaining uncertainties surrounding this category of international crimes.