`titrebSummary`/titrebThis article explores the effectiveness of international criminal justice setting out from the doctrinal thesis of the “integrated law-enforcement system” based on the “shared governance” of public functions between State and international institutions. Particularly, the aims of this article are: to test whether the same integration exists in the areas of individual criminal responsibility and the international criminal justice system; to determine if the current system of international criminal justice, and in particular that established by the ICC Statute, is satisfactory; to verify whether the 2010 Review Conference of the ICC Statute has improved international criminal justice; to examine if the practices of both ICC and other institutions have produced any further improvements; and finally, to explore the necessary reforms to be made in order to turn the ICC into a more effective international criminal justice institution.We support the view that complementarity must be newly construed to render it operational and that attention has to be paid to its “positive” dimension. However, in cases where territorial or national States are unable or unwilling to prosecute the crimes or where they are not Party to ICC Statute, positive complementarity must be “enhanced” by the vertical role played by international institutions. A “positive-enhanced” approach combines the “vertical subsidiarity” of the “integrated law-enforcement system” with a “horizontal” understanding of complementarity, and spreads the co-management of criminal justice throughout all stages of the law-enforcement system (preventive ascertainment, criminal proceeding, ex post control).