The attack on Pearl Harbor (or Hawaii Operation, as it was called by the Imperial General Headquarters)Fukudome, Shigeru, "Hawaii Operation". United States Naval Institute, Proceedings, 81 (December 1955), pp.1315-1331 was a surprise attack conducted by the Japanese navy against the United States" naval base at Pearl Harbor, Hawaii on the morning of Sunday December 7, 1941, later resulting in the United States becoming militarily involved in World War II. It was intended as a preventive action to keep the U.S. Pacific Fleet from influencing the war Japan was planning to wage in Southeast Asia against the Britain, the Netherlands, and the United States. The attack consisted of two aerial attack waves totaling 353 aircraft, launched from six Japanese aircraft carriers. The attack wrecked two U.S. Navy battleships, one minelayer, and two destroyers beyond repair, destroyed 188 aircraft and caused personnel losses of 2,402 killed and 1,282 wounded. Damaged warships included three cruisers, a destroyer, and six battleships (one deliberately grounded, later refloated and repaired; two sunk at their berths, later raised, repaired, and eventually restored to Fleet service). Vital fuel storage, shipyard, maintenance, and headquarters facilities were not hit. Japanese losses were minimal at 29 aircraft and five midget submarines, with 65 servicemen killed or wounded. The aim of the strike was to protect Imperial Japan"s advance into Malaya and the Dutch East Indies — to access their natural resources such as oil and rubber — by neutralizing the U.S. Pacific Fleet. Both the U.S. and Japan held long-standing contingency plans for war in the Pacific which were continuously updated as tensions between the two countries steadily increased during the 1930s, with the Japanese expansion into Manchuria and French Indochina greeted by steadily increased levels of embargoes and sanctions from the United States and other nations. In 1940 under the authority granted by the Export Control Act the U.S. halted shipments of airplanes, parts, machine tools and aviation gasoline, perceived by Japan as an unfriendly act. After it was announced in September export of iron and steel scrap would also be prohibited, Japanese Ambassador Horinouchi protested to Secretary Hull on October 8, 1940 warning that this might be considered an "unfriendly act". The U.S. did not stop oil exports to Japan at that time in part because it was thought in Washington that such an action would be an extreme step, as given Japanese dependence on U.S. oil.Toland, Japan"s War. it was likely to be considered a provocation by Japan. Following Japanese expansion into French Indochina after the fall of France, in the summer of 1941 the U.S. ceased oil exports to Japan, in part because of new American restrictions on domestic oil consumption..President Franklin D. Roosevelt had earlier moved the Pacific Fleet to Hawaii and ordered a military buildup in the Philippines, hoping to discourage Japanese aggression in the Far East. As the Japanese high command was certain that any attack on the United Kingdom"s Southeast Asian colonies would bring the U.S. into the war, a preventive strike appeared to be the only way for Japan to avoid U.S. naval interference. An invasion of the Philippines was also considered to be necessary by Japanese war plans, while for the U.S. reconquest of the same had been included in War Plan Orange as far back as 1897. While the attack accomplished its intended objective, it was completely unnecessary. Unbeknownst to Isoroku Yamamoto, who conceived the original plan, the U.S. Navy had decided as far back as 1935 to abandon "charging" across the Pacific towards the Philippines in response to an outbreak of war (in keeping with the evolution of War Plan Orange).. The U.S. instead adopted "Plan Dog" in 1940, which emphasized keeping the Imperial Japanese Navy (IJN) out of the eastern Pacific and away from the shipping lanes to Australia while the U.S. concentrated on defeating Nazi Germany. The attack was an important engagement of World War II. Unintentionally occurring before a formal declaration of war (which had been scheduled to be delivered shortly prior to the attack beginning),Calvocoressi, Wint, Pritchard, The Penguin History of the Second World War, p. 952-953 it pushed U.S. public opinion from isolationism to the acceptance that participation in the war was unavoidable; with the lack of warning leading Roosevelt to call it "a date which will live in infamy."