While American national security policy grew more interventionist after the Cold War, Washington hoped to shape the world on the cheap. Misled by the stunning success against Iraq in 1991, administrations of both parties pursued ambitious aims with limited force, committing the military frequently but often hesitantly, with inconsistent justification. These ventures produced strategic confusion, unplanned entanglements, and indecisive results. This collection of essays by Richard K. Betts, a leading scholar of international politics, investigates the American use of force since the Cold War, suggesting guidelines for making it more selective and more successful.Betts brings his extensive knowledge of twentieth-century American diplomatic and military history to bear on the full range of theory and practice in national security, surveying Cold War roots of recent initiatives and arguing U.S. policy was always more unilateral than liberal theorists believe. He exposes mistakes in humanitarian interventions and peace operations; reviews the issues raised by terrorism and modern nuclear, biological, and cyber weapons; evaluates the case for preventive war, which almost always proves wrong; weighs the lessons of Iraq, Afghanistan, and Vietnam; assesses the rise of China and the resurgence of Russia; quells concerns about civil-military relations; reveals the anomalies of recent defense budgets; and confronts the practical barriers to effective strategy. Betts argues for more caution and restraint, yet encourages more decisive action when force is required and a calmer assessment of national security interests, even in the face of of global instability and unfamiliar threats.