Claim: World War II involved Japan.

The attack on Pearl Harbor was a surprise military strike by the Imperial Japanese Navy Air Service against the United States naval base at Pearl Harbor , Hawaii Territory , on the morning of December 7 , 1941 . The attack , also known as the Battle of Pearl Harbor , led to the United States ' entry into World War II . The Japanese military leadership referred to the attack as the Hawaii Operation and Operation AI , and as Operation Z during its planning .   Japan intended the attack as a preventive action to keep the U.S. Pacific Fleet from interfering with military actions they 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 -LRB- 18:18 UTC -RRB- . 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 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 . Important base installations such as the power station , shipyard , maintenance , and fuel and torpedo storage facilities , as well as the submarine piers and headquarters building -LRB- also home of the intelligence section -RRB- were not attacked . Japanese losses were light : 29 aircraft and five midget submarines lost , and 64 servicemen killed . One Japanese sailor , Kazuo Sakamaki , was captured .   The surprise attack came as a profound shock to the American people and led directly to the American entry into World War II in both the Pacific and European theaters . The following day , December 8 , the United States declared war on Japan , and several days later , on December 11 , Germany and Italy declared war on the U.S. . The U.S. responded with a declaration of war against Germany and Italy . Domestic support for non-interventionism , which had been fading since the Fall of France in 1940 , disappeared .   There were numerous historical precedents for unannounced military action by Japan , but the lack of any formal warning , particularly while negotiations were still apparently ongoing , led President Franklin D. Roosevelt to proclaim December 7 , 1941 , `` a date which will live in infamy '' . Because the attack happened without a declaration of war and without explicit warning , the attack on Pearl Harbor was later judged in the Tokyo Trials to be a war crime .