In August 1939, the United States imposes a trade embargo on a belligerent Japan, severely limiting raw materials. Influential Japanese army figures and politicians push through an alliance with Germany and Italy in September 1940 despite opposition from the Japanese navy and prepare for war. The newly appointed Commander-in-Chief of the Combined Fleet, Admiral Isoroku Yamamoto, reluctantly plans a pre-emptive strike on the U.S. Pacific Fleet anchored at Pearl Harbor, believing that Japan's best hope of controlling the Pacific Ocean is to quickly annihilate the American fleet. Air Staff Officer Minoru Genda is chosen to mastermind the operation while his old Naval Academy classmate Mitsuo Fuchida is selected to lead the attack.