Does the acquisitions of nuclear weapons by a state lead to peace and stability through deterrence, or does it lead to instability and dangerous crises? This is one of the great debates in international relations scholarship. Michael D. Cohen argues that nuclear weapons acquisition often does dangerously embolden the acquiring state to undertake coercion and aggression behind their nuclear shield, but he says that this behavior moderates over time as particular leaders learn the dangers and limitations of nuclear coercion. The psychological impact of experiencing a nuclear crisis and then regaining control of the situation changes their behavior going forward. This book examines the historical cases of the Soviet Union and Pakistan in depth and also looks at mini-cases that involved the United States, China, and India to make this argument.