History of Hawaii
Pearl Harbor was surprisingly attacked on December 7, 1941 by the Imperial Japanese Navy, killing 2,403 people and sinking the main American battleship fleet. Fortuitously, the four Pacific aircraft carriers were not in port and escaped damage. Hawaii was put under martial law until 1945. Unlike the West Coast of the United States in which 100,000 ethnic Japanese citizens were interned, the Japanese American population in Hawaii completely avoided such similar fate, though hundreds of pro-Japan leaders were arrested. Pearl Harbor was the U.S.' main forward base for the Pacific War. The Japanese tried to invade in summer 1942 but were defeated at the Battle of Midway. Hundreds of thousands of American soldiers, sailors, Marines, and airmen passed through on their way to the fighting.
Empire of Japan
Facing an oil embargo by the United States as well as dwindling domestic reserves, the Japanese government decided to execute a plan developed by Isoroku Yamamoto to attack the United States Pacific Fleet in Hawaii. The Imperial Japanese Navy made its surprise attack on Pearl Harbor, Oahu, Hawaii, on Sunday morning, December 7, 1941. American forces sustained significant losses. The primary objective of the attack was to incapacitate the United States long enough for Japan to establish its long-planned Southeast Asian empire and defensible buffer zones. The American public saw the attack as a treacherous act and rallied against the Japanese. Four days later, Adolf Hitler of Germany, and Benito Mussolini of Italy declared war on the United States, merging the separate conflicts. The United States entered the European Theatre and Pacific Theater in full force, thereby bringing the United States to World War II on the side of the Allies.