This study provides a critical examination of seminal issues within the main areas of criminal justice: its theoretical framework, transnational, and international criminal law. Exploring some of the most interesting challenges arising in these fields, it examines the impact of ’public morality’ on sentencing policy, murder and the mandatory life sentence, genocide, and the notion of magnitude and incitement to terrorism. Taking an approach that is fully integrated in contemporary criminal justice scholarship, it offers a diverse and expert perspective. With a comprehensive introduction and conclusion drawing the various strands together, it offers a rigorous, coherent overview of the key issues in play in contemporary international criminal justice. This diversity and expertise ensures its appeal to a large audience of students, scholars and practitioners of criminal justice around the world.