As shown by the recent trials of Slobodan Milosevic, Charles Taylor, and Saddam Hussein, the large-scale and systematic commission of international crimes is usually planned and set in motion by senior political and military leaders. Nevertheless, the application of traditional forms of criminal liability leads to the conclusion that they are mere accessories to such crimes. This does not reflect their central role and often results in a punishment which is inappropriately low in view of the impact of their actions and omissions. For these reasons, international criminal law has placed special emphasis on developing the concepts of joint criminal enterprise (also known as the common purpose doctrine) and the control of the crime, which aim at better reflecting the central role played by senior political and military leaders in campaigns of large scale and systematic commission of international crimes. The Rome Statute of the International Criminal Court, the case law of the International Criminal Tribunal of the former Yuglosavia, and the case law of the International Criminal Tribunal for Rwanda have, in recent years, played a unique role in the achievement of this goal. The book is a comprehensive study of the modes of responsibility and liability in international criminal law. It fills a gap in the literature, as few books detail the drafting of indictments. It covers both substantive and procedural law and will be useful for both academics and practitioners.