Isoroku Yamamoto

Isoroku Yamamoto (1884–1943) was Marshal Admiral of the Imperial Japanese Navy and Commander-in-Chief of the Combined Fleet during the first sixteen months of the Pacific War. A pioneer of carrier aviation who had lived in the United States and warned that Japan could never win a protracted industrial war against America, he nonetheless conceived and directed the surprise attack on Pearl Harbor and the fateful campaign at Midway Atoll.

Witnessing American Industry and Championing Carrier Aviation

Born in Nagaoka in Niigata Prefecture—named 'Isoroku' ('fifty-six') because his father was fifty-six years old at his birth—he graduated from the Imperial Japanese Naval Academy in 1904. The following year, as a young ensign aboard the cruiser Nisshin at the Battle of Tsushima during the Russo-Japanese War, he lost the index and middle fingers of his left hand in an explosion.

From 1919 to 1921 Yamamoto studied English and oil economics at Harvard University, later returning to Washington, D.C. as naval attaché. Traveling extensively across the United States, he visited Texas oil fields and Henry Ford's vast automobile factories in Detroit. The experience convinced him of two truths: that modern total war was decided by industrial capacity and oil reserves, and that aircraft carriers and naval aircraft—not giant battleships—would rule future naval warfare.

Reluctant Architect of the Pearl Harbor Attack

During the late 1930s, as Japanese army militarists pushed for the Tripartite Pact with Nazi Germany and Fascist Italy, Yamamoto—then Vice Minister of the Navy—openly opposed the alliance and warned against provoking war with the United States and Britain, attracting death threats from ultranationalist assassins. Appointed Commander-in-Chief of the Combined Fleet in August 1939, he cautioned Prime Minister Fumimaro Konoe that while he could 'run wild' for the first six to twelve months of a war with America, he had 'utterly no confidence' if the conflict dragged on for two or three years.

When Japan's cabinet resolved upon war in 1941 following the U.S. oil embargo, Yamamoto argued that Japan's only slim chance lay in a knockout blow on the opening day: sending all six fleet carriers across the North Pacific to destroy the U.S. Pacific Fleet at Pearl Harbor and shock Washington into a negotiated settlement. Executed on December 7, 1941, the strike crippled eight American battleships, but missed the U.S. aircraft carriers at sea and galvanized the American public into an uncompromising war to the finish.

Defeat at Midway and Interception Over Bougainville

Hoping to draw out and destroy the remaining American carriers before U.S. shipyards could overwhelm Japan in numbers, Yamamoto launched a complex offensive against Midway Atoll in June 1942. However, U.S. Navy cryptanalysts had broken the Japanese naval code (JN-25). Forewarned American carrier dive-bombers caught Yamamoto's strike force by surprise, sinking four Japanese fleet carriers in a single day and permanently shifting the balance of power in the Pacific.

In April 1943, following the costly loss of Guadalcanal, Yamamoto embarked on a frontline inspection tour of the Solomon Islands to boost morale. Once again, American codebreakers intercepted and decrypted his detailed flight itinerary. Authorized by President Franklin D. Roosevelt, Operation Vengeance sent long-range U.S. Army Air Forces P-38 Lightning fighters to ambush Yamamoto's Mitsubishi G4M Betty bomber over Bougainville Island on April 18, 1943, shooting down the plane and killing Japan's foremost naval commander at age fifty-nine.