What is an International Crime?

Nearly all International Criminal Law scholars accept the idea that an international crime is an act that is directly criminalized by international law. Professor Heller will challenge that definition, what he calls the "direct-criminalization thesis," in this lecture. More specifically, he argue that the thesis can only be defended on the basis of an unconvincing and illegitimate naturalist understanding of the creation of international law -- and that any attempt to defend the direct-criminalization thesis on positivist grounds collapses it into what he calls the "national-criminalization thesis", the idea that an international crime is an act that all states are obligated to domestically criminalize.