As the costs of a preemptive foreign policy in Iraq have become clear, strategies such as containment and deterrence have been gaining currency among policy makers. This comprehensive book offers an agenda for the contemporary practice of deterrence—especially as it applies to nuclear weapons—in an increasingly heterogeneous global and political setting. Moving beyond the precepts of traditional deterrence theory, this groundbreaking volume offers insights for the use of deterrence in the modern world, where policy makers may encounter irrational actors, failed states, religious zeal, ambiguous power relationships, and other situations where the traditional rules of statecraft do not apply. A distinguished group of contributors here examines issues such as deterrence among the Great Powers; the problems of regional and nonstate actors; and actors armed with chemical, biological, and nuclear weapons. Complex Deterrence will be a valuable resource for anyone facing the considerable challenge of fostering security and peace in the twenty-first century.