Throughout the 1930s Japan had built up an empire in the Far East. It invaded Manchuria in North East China in 1931 and then moved deeper into the country in 1937.
By July 1941, Japan had flooded French Indochina (now Vietnam) with troops. Japans aims were clear. The Japanese wanted to be the dominant power in Asia and remove the power and influence of the Europeans and the Americans from the region.
The most powerful opponent the Japanese would face was America. The United States had extensive interests in the Pacific Ocean and would not allow another power to dominate the Pacific.
The USA also had a powerful Pacific fleet, with bases in Pearl Harbor, Hawaii and in the Philippine Islands.The Japanese plan was both risky and daring.
On December 7th 1941 Japanese aircraft from aircraft carriers attacked the US fleet anchored at Pearl Harbor and took the Americans by surprise. 18 American ships were sunk or severely damaged in the attack. 188 aircraft were destroyed before they had even left the ground. Japan hoped to use this breathing space to build up its own empire in Asia and the Pacific to such an extent that a weakened America would make peace.
Their advances seemed unstoppable. Within 7 hours of the Pearl Harbor attack Japanese aircraft bombed US bases at Guam, Wake and Midway.
British aircraft at Hong Kong were destroyed, Singapore was attacked and a large Japanese force landed on the coast of British Malaya. Hong Kong fell on Christmas Day; 11,000 British soldiers were taken prisoner.
By April of 1942 Japanese forces had occupied much of Papua New Guinea, the Dutch East Indies, and the Phillippines, in spite of determined American resistance. They had launched bombing raids on Darwin in Northern Australia and as island after island fell Australia, refuge for American forces retreating from the Phillippines, seemed under real threat.
The bad news for the Japanese was that the USAs key ships, its aircraft carriers, had not been at Pearl Harbor at the time of the attack. US Admiral Halsey was able to use them effectively through 1942 while American shipyards replaced the losses at Pearl Harbor.
In June 1942 the Japanese suffered their first big defeat at the Battle of Midway. They lost 4 out of 6 vital aircraft carriers in this one battle. US forces then went on to take the strategically important island of Guadalcanal in a campaign which lasted from August 1942 to February 1943 and caused major Japanese losses of ships, aircraft and around 20,000 troops.
From this point the Americans and their Allies began to drive the Japanese back. Australian forces began to gain ground in New Guinea. US air and sea attacks were followed by landings on Japanese held territories.
The Japanese troops fought ferociously, especially as the Americans approached Japans home islands in 1945. There were two particularly costly battles at Iwo Jima in February-March and Okinawa from April to June 1945. At the same time US aircrews carried out devastating air raids against major Japanese cities, especially the capital Tokyo.
By this time Allied scientists had developed a new weapon, the atomic bomb. There was much debate about whether or not this terrifying new weapon should be used. However, in the end it was decided that using it would shorten the war and so reduce casualties. The first bomb was dropped on Hiroshima on August 6th 1945. Three days later a more powerful bomb was dropped on Nagasaki. Soon afterwards Japan surrendered and the war officially ended on September 2nd 1945.