THE SECOND MOST POWERFUL MAN IN THE WORLD

A welcome biography of Franklin Roosevelt’s closest adviser.

Though William D. Leahy (1875-1959) lacked charisma, his importance has been surprisingly muted over the decades; this excellent life appraisal should help restore it. Graduating from the Naval Academy in 1897, Leahy rose steadily, always impressing superiors, according to O’Brien (Strategic Studies/University of St. Andrews; How the War Was Won: Air-Sea Power and Allied Victory in World War II, 2015, etc.). “It was striking,” he writes, “how often a senior commander, once he had Leahy serve beneath him for the first time, tried to co-opt the younger officer in the future.” He hit the jackpot in 1913, when Roosevelt, then the assistant secretary of the Navy, took a liking to him, and they became friends. Leahy reached the Navy’s highest office, Chief of Naval Operations, in 1937. After his retirement in 1939, Roosevelt sent him on diplomatic missions but made him chief of staff after the U.S. entered World War II. O’Brien disagrees with most historians, who believe America’s most influential military man during WWII was Gen. George Marshall. Marshall was an “august, formal, and upright figure” with everyone, including Roosevelt, who preferred a chatty informality with his colleagues. FDR could relax with Leahy and call him “Bill.” The first time he called Marshall “George” was the last. Roosevelt vastly preferred Leahy’s company and advice, and when Marshall disagreed with Leahy, Marshall lost. In case readers have doubts, the author produces a table that juxtaposes their opposing strategic views. Sure enough, they differed on invading North Africa in 1942, invading France in 1943, and whether to give defeating Germany priority over Japan. With these and all others, Leahy prevailed. Upon assuming office in 1945, Truman kept Leahy, but he retired into obscurity in 1949.

A lucid, opinionated life of a man who exerted far greater influence than historians give him credit for—and a book sure to invite spirited argument from historians who disagree.