1941 – World War II: Attack on Pearl Harbor – The Imperial Japanese Navy carries out a surprise attack on the United States Pacific Fleet and its defending Army and Marine air forces at Pearl Harbor, Hawaii
. The attack on Pearl Harbor, also known as the Battle of Pearl Harbor, the Hawaii Operation or Operation AI by the Japanese Imperial General Headquarters, and Operation Z during planning, was a surprise military strike by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii Territory, on the morning of December 7, 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. Over the next seven hours there were coordinated Japanese attacks on the U.S.-held Philippines, Guam and Wake Island and on the British Empire in Malaya, Singapore, and Hong Kong. The attack commenced at 7:48 a.m. Hawaiian Time. The base was attacked by 353 Imperial Japanese fighter planes, bombers, and torpedo planes in two waves, launched from six aircraft carriers. All eight U.S. Navy battleships were damaged, with four sunk. All but the USS Arizona (BB-39) were later raised, and six were returned to service and went on to fight in the war. The Japanese also sank or damaged three cruisers, three destroyers, an anti-aircraft training ship, and one minelayer. 188 U.S. aircraft were destroyed; 2,403 Americans were killed and 1,178 others were wounded.