14. Norms of customary international law are characterized by the two familiar components of state practice and opinio juris.  In concluding that customary international law permitted a conviction for, inter alia, a crime against humanity through participation in a joint criminal enterprise, the Tadić Appeals Judgement held that the recognition of that mode of liability in prosecutions for crimes against humanity and war crimes following World War II constituted evidence of these components.[1]  The ICTY Appeals Chamber has placed similar reliance in other cases on proceedings held following World War II, including the proceedings before the International Military Tribunal and before tribunals operating under Allied Control Council Law No. 10 (“Control Council Law No. 10”), as indicative of principles of customary international law at that time.[2]  For the reasons that follow, the Appeals Chamber concludes that these proceedings, as well as the text and drafting history of the Genocide Convention of 1948, lead to the conclusion that customary international law criminalized intentional participation in a common plan to commit genocide prior to 1992.