a US naval base in a bay on the southern shore of Oahu Island, 10 km west of Honolulu, in the Hawaiian Islands. On Dec. 7, 1941, Japan attacked Pearl Harbor and thereby unleashed the war in the Pacific Ocean. The naval base at Pearl Harbor was founded in the early 20th century.
On Dec. 7, 1941, the main forces of the US Pacific Fleet were in Pearl Harbor, including eight battleships, eight cruisers, 29 destroyers, five submarines, nine minelayers, ten minesweepers, and 24 auxiliary vessels. The air forces of the base totaled 394 airplanes. The Japanese naval command, who had extensive knowledge of the disposition of the American ships at the base and of the location of the means of defense, drew up a plan for a surprise attack on Pearl Harbor.
On November 26 a Japanese aircraft carrier task force, consisting of two battleships, six aircraft carriers with 353 airplanes, nine destroyers, and three submarines, under the command of Admiral Yamamoto, left Khitokappu Bay in the Kuril Islands. At dawn of December 7 (the night of December 7, Tokyo time) the task force reached an area 370–500 km north of Oahu Island. In addition, more than 20 Japanese submarines had been deployed ahead of time in the vicinity of Pearl Harbor. Airplanes took off from the Japanese aircraft carriers in two echelons from different directions and for two hours (7:50–9:45 A.M. local time) made several successive strikes at American ships, airfields, and coastal batteries.
Although war with Japan was anticipated and information on the impending attack on Pearl Harbor was available, the American command was caught by surprise. The combat readiness of the base was low at the time. (For instance, strategic air reconnaissance and air defense were inadequate and poorly organized, and ships and aircraft were compactly concentrated.) As a result, the Japanese sank four battleships, two destroyers, and one minelayer; damaged four battleships, three cruisers, and one destroyer; destroyed 188 airplanes; and killed more than 3,000 men. The Japanese fleet lost 29 airplanes and five midget submarines.
On Dec. 8, 1941, the USA and Great Britain declared war on Japan. World War II (1939–45) spread to the Pacific Ocean. Having seized the strategic initiative and gained naval supremacy, the Japanese armed forces launched aggressive operations along the southern axis and won great strategic victories in Malaya, the Philippines, Burma, Indonesia, and New Guinea.