Domestic Implementation of the Rome Statute in Japan

When Japan acceded to the Rome Statute on July 17, 2007, it enacted the “Act on Cooperation with the International Criminal Court”. However, the present Act aims at ensuring procedural cooperation with the ICC, and does not set out new substantive provisions nor change existing Penal Code in order for Japan to try and punish the perpetrators who commit the crimes referred to in Article 5 of the Rome Statute. From the consideration that there was “no need to think about unthinkable things” and enacting a comprehensive law to criminalize every act and omission would delay the accession to the Rome Statute, Japan adopted a “minimalist” approach according to which a State Party does not change substantive criminal law and domestically punish the crimes within the Rome Statute as far as its existing laws are applicable. In fact, most of the conducts constituting the crime of genocide, crimes against humanity and war crimes constitute ordinary crimes under the Penal Code of Japan if they are committed in the territory of Japan. However, the crimes within the jurisdiction of the ICC, save war crimes as grave breaches, cannot be tried by a Japanese court if they are committed by foreigners against foreigners outside the territory of Japan. In terms of those crimes, Japan would have to entrust the prosecution and punishment of perpetrators to the ICC pursuant to the principle of complementarity. In contrast, the Cooperation Act, with taking into account a vertical relation between the ICC and a State Party, prescribes in detail the ways of cooperation with the ICC such as the procedures of surrender, production of evidence and enforcement.