Canada was the first country to adopt legislation to implement the ICC Statute. Over the past year, legislation to implement the ICC Statute into national law has been adopted in several other countries and is pending in many more. What we can expect to see in the coming years, then, is not so much the spectre of ‘centralised’ international criminal justice, administered from The Hague—the seat of the International Criminal Court—but a diffusion of international justice from The Hague to states.

It will not necessarily involve a direct application of ‘ICC law’ in national courts. A review of the existing or pending legislation to implement the Statute reveals fascinating divergences. For example, while states cannot define the ICC crimes more narrowly than in the Statute, there is nothing to stop them adopting broader definitions. States can therefore make a vital contribution to developing international humanitarian law and human rights law.

Undoubtedly, when the International Criminal Court comes into being, the jurisprudence of all criminal courts—national and international—will nourish the others and will make a significant contribution to the further development of international humanitarian law. This cross-fertilisation concerns not only substantive law but also procedural law. Such combined efforts are the necessary response in the ongoing and never-ending fight against impunity. International criminal law can only hope to serve as a deterrent force if it is credibly enforced, whether by international or national courts, but especially by the latter.