The attack on Pearl Harbor was a surprise military strike by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, in the United States Territory of Hawaii, on the morning of 7 Dec 1941. The attack led to the United States’ entry into World War II.
Japan intended the attack as a preventive action to keep the U.S. Pacific Fleet from interfering with military actions the Empire of Japan planned in Southeast Asia against overseas territories of the United Kingdom, the Netherlands, and the United States. There were near-simultaneous Japanese attacks on the U.S.-held Philippines, Guam and Wake Island and on the British Empire in Malaya and Hong Kong. The attacks – from troop landings at Kota Bharu, Malaya, to the air attacks ranging geographically from Hong Kong to Pearl Harbor – took place over seven hours.