During the Cold War, the superpowers shared a conception of strategic stability. It was for coexistence and a status quo frozen in place by the calculus of mutually assured destruction from nuclear weapons. In short, nuclear weapons promoted great-power peace. The United States made and continues to make its decisions about changes to force posture, risk of escalation, and prospects for arms control with strategic stability in mind. But today's international system is complicated by regional rivalries, rising states, more nuclear powers, asymmetric warfare, and non-state actors. The purpose of this book is to unpack and examine how different states view strategic stability, the use or non-use of nuclear weapons, and whether or not strategic stability is still a useful concept. The contributors to this book examine current and potential nuclear powers including the United States, Russia, China, India, Iran, Israel, Pakistan, and Saudi Arabia. This book makes an important contribution toward understanding how nuclear weapons will impact the international system in the twenty-first century.