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Pearl Harbor was established as a U.S. naval base in 1908, and remains a vital part of the U.S. defense establishment today. Pearl Harbor is a national historic landmark because of its essential contribution to the rise of the U.S. as a major power in the Pacific and the crucial role it played in World War II, beginning with the Dec. 7 attack.

Prelude to War

Between the middle of the 19th century and the beginning of the 20th, Japan transformed itself from a closed feudal society to a modern industrial and military power. In the 1930s, under the increasing influence of their military, Japan embarked on a series of conquests. With the start of World War II in Europe, resource-poor Japan saw an opportunity to seize European colonies in Southeast Asia with its resources of oil, coal, rubber, and tin.

Relations with the United States had been deteriorating since Japan took Peking in 1937. Because of rising tensions and continued Japanese aggression, the U.S. moved its Pacific Fleet to Hawaii in the spring of 1940. In July, the U.S. placed restrictions on shipments of oil and other war material to Japan. In July 1941, the U.S and other nations froze all Japanese assets. Rather than change its expansionist policies, Japan chose war with the United States to protect its territorial gains.

While diplomatic efforts were underway to resolve differences with Washington, naval planners in Japan were considering an attack on Hawaii as early as 1940. On November 25, 1941, as these negotiations were failing, a fleet of 32 warships, including six aircraft carriers and 432 planes, sailed for Hawaii on a course north of the usual shipping lanes.

Approximately 30 submarines, five carrying midget subs, sortied a day later to approach from the southwest.

The Attack

At 0600 on Sunday, December 7, 1941, Japan launched the initial strike force of 183 aircraft. At about 0645, an unidentified submarine was depth-charged at the Pearl Harbor entrance. Subsequently, approaching unidentified aircraft were detected by radar. Although U.S. forces were on war alert, these indicators of the impending attack were not communicated to those in command. The first wave of aircraft struck at 0755 in an attack that lasted half an hour. After a lull, the second wave of the attack began at 0845 and lasted another hour.

Oahu’s military airfields were attacked to prevent interdiction of the striking forces; several hundred U.S. aircraft were damaged or destroyed. Pacific Fleet aircraft carriers and battleships would be the primary targets. Fortunately, all three Hawaii-based carriers were at sea. The eight battleships in port were attacked with bombs and torpedoes designed for the shallow waters of Pearl Harbor. Five battleships and three other ships were sunk or beached; three battleships and ten other ships were damaged. More than 2,000 Sailors lost their lives in the attack, along with several hundred other servicemembers and civilians.


Although the Japanese attack was accomplished according to plan, it was, in retrospect a strategic failure. U.S. isolationist sentiment dissolved. Moreover, seven months later, fuel supplies spared in the attack contributed to the defeat of a Japanese carrier task force by U.S. Pacific Fleet carriers at Midway, in a battle that turned the tide of the war.


Related Links:

Joint Base Pearl Harbor-Hickam Historic Sites app (Free download for iPhone & iPad devices)

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