A candid memoir by a long-serving American statesman recounting his time leading the Defense Department through wars in Afghanistan and Iraq and the transitions between presidential administrations; it blends behind-the-scenes accounts of high-stakes meetings and policy debates with reflections on civil-military relations, leadership, institutional reform, and the burdens of public service, offering forthright assessments of presidents, generals, and allies while explaining the complexities and limits of wielding power in pursuit of national security goals.