This book examines the main decisions taken in the 1994, 2001, and 2010 Nuclear Posture Reviews regarding U.S. nuclear capabilities and declaratory strategy, and the policy debates that followed the publication of each NPR, focusing on deterrence and other objectives of U.S. national security strategy. It analyzes and compares the post-Cold War NPRs to understand how each administration attempted to shape and direct policy, and how key issues were framed and addressed by policy makers and commentators. The concluding chapter identifies continuities and discontinuities in the NPRs, and considers how the roles of nuclear weapons, deterrence theory, and force structure have been addressed since the end of the Cold War. Continuities across the NPRs include the reduced role of the U.S. nuclear arsenal, deterrence objectives keyed to contemporary threats, nuclear arms control with Russia, and a force structure that emphasizes diverse capabilities, including non-nuclear offensive and defensive assets. Fundamental issues concerning nuclear deterrence requirements for U.S. national security nonetheless remain unresolved, owing in part to fundamentally different policy views and priorities. U.S. deterrence objectives have remained fairly stable; definitions of deterrence requirements have changed markedly in each post-Cold War administration, with increasingly lower nuclear force levels.