Pacific campaign

Pacific campaign (World War II) (1941–5) On 7 December 1941 the Japanese entered World War II by attacking the US naval base of Pearl Harbor in Hawaii. While the attack did not, as the Japanese had hoped, wipe out the entire US Pacific fleet, it took a surprised USA a few months to gather its forces in the area. During this time, Japan used its alliances with the Vichy colonial government in Indochina as well as with Thailand for a rapid advance into neighbouring Malaya, and Singapore. In Burma (Myanmar) as well as in the Dutch East Indies (Indonesia), its advancing armies were welcomed by the respective independence movements as liberators from European colonialism. After their naval victory in the Battle of the Java Sea (27 February–1 March), the Japanese occupied the Dutch East Indies, and by April the Philippines and northern New Guinea were occupied.

As the Japanese advanced precariously close to Australian New Guinea, which the surrendered British and Commonwealth garrison at Singapore could no longer defend, US General MacArthur organized a resolute stance against them. US success at the Battle of the Coral Sea lifted the threat of a military invasion off Australia, while the subsequent Battle of Midway Island shifted the balance of naval power decisively to the USA. In August 1942 US marines landed on Guadalcanal and Tulagi in the Solomon Islands, where fighting raged until February 1943. The remaining Solomon Islands were retaken during the year, while in November 1943 US marines captured Kiribati.

Having established control over the Pacific as such, MacArthur embarked upon the Philippines campaign, and advanced north to various Pacific islands that could be used for an eventual invasion of Japan. The USA occupied New Guinea from 1943, and during 1944 US forces gradually moved back towards the Philippines. The Japanese were defeated at the Battle of the Philippines Sea. In July 1944 the Mariana Islands were taken, from which bombing raids on Tokyo were launched. The Battle of Leyte Gulf marked the effective end of Japanese naval power, while on the mainland the Burma campaign had reopened land communication with China. Manila fell in March 1945 and from April to June US forces gradually captured Okinawa, at the cost of very high casualties on both sides (5,900 Japanese planes, as well as 1,900 kamikaze attacks; 763 US planes and 12,000 dead). Faced with US estimates that an invasion of mainland Japan would cost hundreds of thousands of Allied lives, President Truman ordered instead the dropping of the atomic bomb on Hiroshima and Nagasaki, after which Japan surrendered unconditionally on 2 September 1945.