The Japanese take advantage of American blunders to launch a surprise attack on Pearl Harbor.

After Japan signs the Axis Alliance with Germany in 1941, Adm. Isoroku Yamamoto, commander of the Japanese Navy, realizes that the center of United States Naval operations at Pearl Harbor must be destroyed if Japanese power is to spread in the Pacific. In Washington, Secretary of State Cordell Hull and Secretary of War Henry L. Stimson suggest the cooling of diplomatic relations with Japan after the treaty, but few in the U. S. military or diplomatic corps fear imminent attack. At Pearl Harbor, Gen. Walter C. Short, commander of U. S. ground forces, is more worried about sabotage than foreign attack and orders all planes to be placed in the middle of the runway; in addition, the radar system he has developed is rendered useless since its operators do not know how to interpret the readings. After Japan invades Indochina, Lieut. Col. Rufus S. Bratton of U. S. Army Intelligence convinces Stimson that a Japanese attack is impending, and Pearl Harbor is placed on full alert on November 30th; few preparations are actually made, however, and within a couple of days the base is back to its unprepared state. Just before the actual attack, Bratton learns from a decoded message that Japanese Adm. Chuichi Nagumo has received orders to sail for Hawaii with six aircraft carriers, but the intelligence officer is unable to locate Army Chief of Staff George C. Marshall, who is horseback riding, and President Roosevelt is warned only hours before the bombing is to begin. Japan instructs Ambassador Kichisaburo Nomura to present Hull with an ultimatum, which the Japanese expect to be refused, in order to make the attack seem retaliatory, but an inept typist in the Japanese Embassy delays the message so that its delivery coincides with the actual bombing. The Japanese attack results in the devastation of almost all Navy ships and planes based in the Pacific, but Yamamoto regards the holocaust with mixed emotions because of the anticipated American retaliation.