The Japanese had great difficulty replacing their losses in ships and aircraft, while American factories and shipyards produced ever increasing numbers of both. The Allies adopted a Europe first stance, giving first priority to defeating Nazi Germany, but still managed to bring to bear the vast industrial might of the United States. The Japanese achieved great success in the initial phase of the campaign, but were gradually driven back using an island hopping strategy. The Pacific War saw the Allies pitted against Japan, the latter aided by Thailand and to a lesser extent by the Axis powers, Germany and Italy.

However, it is more widely accepted that the Pacific War itself began on 7 December (8 December Japanese time) 1941, when the Japanese simultaneously attacked American military bases in Hawaii, Wake Island, Guam, and the Philippines and invaded Thailand and the British colonies of Malaya, Singapore, and Hong Kong.

The Second Sino-Japanese War between the Empire of Japan and the Republic of China had been in progress since 7 July 1937, with hostilities dating back to 1931 with the Japanese invasion of Manchuria. It was geographically the largest theater of the war, including the vast Pacific Ocean theater, the South West Pacific theater, the Second Sino-Japanese War, and the Soviet–Japanese War. The Pacific War, sometimes called the Asia–Pacific War, was the theater of World War II that was fought in eastern Asia, the Pacific Ocean, the Indian Ocean, and Oceania. The UN Security Council ended the vast trusteeship in stages, from 1986 to 1994, with the US gaining the territory of the Northern Mariana Islands. The Trust Territory of the Pacific Islands is created by the United Nations and placed under the authority of the United States.Seizure and annexation of South Sakhalin and the Kuril Islands by the Soviet Union.

Cession of Japanese-held islands in the Central Pacific Ocean to the United Nations.Liberation of Korea and Manchuria from Japanese rule, followed by the division of Korea.Removal of Japanese troops occupying parts of China and the retrocession of Taiwan to China.Substantial weakening of European colonial powers and the gradual decolonization of Asia.

Us navy pacific war documentaries utube