Robert S. McNamara was widely considered to be one of the most brilliant men of his generation. He was an invaluable ally of Presidents John F. Kennedy and Lyndon B. Johnson as U.S. secretary of defense, and he had a deeply moving relationship with Jackie Kennedy. But to the country, McNamara was the leading advocate for American escalation in Vietnam. He strongly advised Johnson to deploy hundreds of thousands of American ground troops, just weeks before concluding that the war was unwinnable, and for the next two and a half years, McNamara failed to urge Johnson to cut his losses and withdraw. McNamara at War examines McNamara's life of intense personal contradictions, following his childhood, his career as a young faculty member at Harvard Business School, and his World War II service, to his leadership of the Ford Motor Company and the World Bank. Philip and William Taubman had access to materials previously unavailable to McNamara biographers, including Jacqueline Kennedy's warm letters to McNamara during the Kennedy and Johnson administrations and beyond; family correspondence dating back to McNamara's service in World War II; and a secret diary maintained by McNamara's top Vietnam policy aide. What emerges is the comprehensive story of the infamous former leader of the Pentagon: riven by melancholy, guilt, zealous loyalty, and a profound inability to admit his flawed thinking about Vietnam before it was too late. McNamara at War is a portrait of a man at war with himself--with a grave influence on the history of the United States and the world.