The Second Most Powerful Man in the World

Phillips Payson O'Brien's biography of Admiral William D. Leahy fills a curious gap in the historical record of World War II leadership. Despite serving as chief of staff to Franklin D. Roosevelt and later Harry Truman, and despite holding a position that placed him at the center of American military and diplomatic decision-making, Leahy has remained a relatively obscure figure compared to contemporaries like George Marshall or Dwight Eisenhower. O'Brien sets out to correct this oversight, and the result is a thorough and engaging account of a man whose influence far outweighed his public profile.

Leahy's career began long before his years in Washington. He served in the Navy for decades, rising through the ranks and eventually becoming Chief of Naval Operations in the late 1930s. This naval background is essential to understanding his later role, as it gave him a depth of institutional knowledge and personal relationships that proved invaluable when Roosevelt called him back into service. After a stint as ambassador to Vichy France, Leahy was appointed to a newly created position: chief of staff to the Commander in Chief. This role, largely without precedent, allowed him to become the President's closest military advisor and the presiding officer of the Joint Chiefs of Staff.

O'Brien does an admirable job of explaining just how significant this position was. Leahy sat in on nearly every major strategic discussion of the war, from the planning of D-Day to decisions about the Pacific campaign. He was present at the major Allied conferences in Casablanca, Tehran, and Yalta, offering counsel to Roosevelt and helping to coordinate between the various branches of the American military. The book makes clear that Leahy was not merely a bureaucratic functionary but an active shaper of policy, someone whose judgment Roosevelt trusted implicitly.

One of the strengths of this biography is its attention to Leahy's personality and working style. He was known for his discretion, his loyalty, and his ability to manage the egos and ambitions of powerful men without drawing attention to himself. This temperament made him effective in his role but also explains why he has been overlooked by historians who tend to favor more colorful or outspoken figures. O'Brien argues persuasively that this very quality of self-effacement is part of what made Leahy so valuable to Roosevelt, and later to Truman, who retained him in the position after Roosevelt's death.

The book also explores Leahy's views on some of the most consequential decisions of the war, including his skepticism about the atomic bomb and his assessments of Soviet intentions as the war drew to a close. These sections are particularly valuable, as they offer insight into the internal debates that shaped American strategy at pivotal moments. O'Brien draws on archival sources, including Leahy's own diary, to reconstruct these discussions with a level of detail that adds texture to familiar historical events.

Stylistically, O'Brien writes with clarity and confidence, making complex military and diplomatic history accessible without oversimplifying it. The narrative moves at a steady pace, balancing biographical detail about Leahy's personal life with the broader sweep of wartime events. Readers with an interest in World War II history, presidential decision-making, or military biography will find much to appreciate here.

If there is a shortcoming to the book, it may be that Leahy himself remains somewhat elusive as a personality, even after several hundred pages. His reticence, so central to his professional success, also makes him a challenging subject for a biographer. O'Brien works around this limitation by focusing on Leahy's actions and his place within the larger historical narrative, which is perhaps the most sensible approach given the available sources.

Overall, this biography succeeds in its primary goal: restoring William Leahy to his rightful place in the history of American power during one of its most critical periods. It is a well-researched and thoughtfully written account that will appeal to both general readers and those with a more specialized interest in the era.