A Sunday raid that ended American neutrality overnight
On 7 December 1941 Japan’s carrier force under Chūichi Nagumo struck the U.S. Pacific Fleet at Pearl Harbor, Oahu, while the United States was still neutral. Three hundred fifty-three aircraft hit in two waves beginning at 7:48 a.m. Hawaiian time.
Six carriers launched the planes, a mix of fighters, level and dive bombers, and torpedo bombers. Every one of the eight American battleships in harbour was damaged and four went down, though all except the Arizona and the Utah were raised, and six eventually fought again. Cruisers, destroyers and other vessels were also sunk or damaged. Japanese planners called the operation Operation Z while preparing it, and Hawaii Operation or Operation AI afterward.
The rivalry was old. Japan had watched American expansion across the Pacific since the late 1890s, including the annexation of Hawaii and the Philippines, and war between the two powers was contemplated from the 1920s. The First World War had convinced Japanese strategists that a modern conflict would be long and embargo-prone, so the country needed iron, oil and other resources its home islands could not supply. Relations stayed cordial enough for trade until the 1931 invasion of Manchuria, and full war with China followed in 1937.
Pressure then built step by step. After the sinking of the USS Panay and the Nanjing massacre in late 1937, American firms stopped selling war materiel to Japan. When Japan moved into French Indochina in 1940, Washington halted aircraft, machine tools and aviation fuel, and Roosevelt shifted the Pacific Fleet from San Diego to Hawaii as a deterrent. Oil exports finally stopped in July 1941, and Japan set its sights on the oil of the Dutch East Indies. Admiral Isoroku Yamamoto had pushed for a Pearl Harbor strike since early that year, once threatening to resign to get approval.
Japan’s last offer on 20 November sought sanctions relief and aviation fuel; the Hull note of 26 November demanded full withdrawal from China. Hirohito, who had approved the plan on 5 November, gave final authority on 1 December. Within about seven hours of the raid Japan also struck the Philippines, Guam, Wake, Midway, Malaya, Singapore and Hong Kong. Germany and Italy declared war on the United States on 11 December, though the Tripartite Pact did not require it.
Source: Attack on Pearl Harbor
