This edited volume seeks to reassess the old and to analyse and develop novel approaches to the notion of proportionality in criminal matters and the new security architecture. The discourse is not limited to conventional constitutional constellations and standard problems of sentencing in traditional criminal proceedings. Rather, the book offers an interdisciplinary and cross-jurisdictional exploration of highly topical, proportionality-related issues pertinent to penal theory and legal philosophy, criminalisation policies, security and anti-terrorism strategies, alternative types of justice delivery, and supranational enforcement as well as human rights and international criminal and humanitarian law. In today’s global risk society, with its numerous visible and invisible enemies of the state and the individual, balancing freedom and security has become nothing less than an attempt at untying a Gordian knot. Against this background, the proportionality of measures of crime prevention and repression is unquestionably an issue of utmost importance, which basic research and legal policy in rule-of-law based systems are urgently called to address. The timely and fascinating contributions in this book, covering jurisdictions from both the common law and the civil law as well as hybrid and international jurisdictions, will appeal to academics, researchers, policy advisers and practitioners working in the areas of national and international criminal law, comparative criminal justice/criminology and legal philosophy as well as constitutional and security law.