Most world leaders agree that nuclear terrorism represents the gravest international security challenge today. Many scholars and practitioners, however, argue that the United States remains ill-prepared to cope with this serious and real threat. What role should the U.S. play in confronting and combating this danger? Is nuclear terrorism preventable? What steps have the U.S. already taken to prevent a nuclear catastrophe and what future steps should the U.S. government take? Esteemed scholars, scientists and policymakers address these crucial questions from all sides - strategic, tactical, ideological, and technical. This special volume of "The ANNALS" clarifies and assesses that threat of a nuclear terrorist attack and examines possible solutions for preventing such a catastrophic event.