Pacific War

Pacific War
Part of World War II
Map indicating US landings during the Pacific War
Map showing the main areas of the conflict and Allied landings in the Pacific, 1942–45
7 December 1941 – 2 September 1945
(3 years, 8 months, 3 weeks and 5 days)

Allied victory


Allied occupation of Japan


 United States


 United Kingdom

 New Zealand

 Soviet Union

and others[b]


and others[c]
Commanders and leaders
Republic of China (1912–1949) 14,000,000[2]
United States 3,621,383+ (1945)[d]
British Raj 2,000,000[7]
Soviet Union 1,669,500 (1945)[8]
Australia 600,000
United Kingdom 400,000[7]
Netherlands 140,000[9][e]
Empire of Japan 7,800,000–7,900,000 (1945)[10][11][12]
Thailand 126,500[13]
Manchukuo, Flag of the Republic of China-Nanjing (Peace, Anti-Communism, National Construction).svg, and others: ~1,000,000+ (1945)[14]
Casualties and losses
  • Military
    4,000,000+ dead (1937–45)
  • Civilian deaths
    26,000,000+ (1937–45)[g]
  • Military
    2,500,000+ dead (1937–45)[h]
  • Civilian deaths
  • a Including its islands and neighboring countries
  • b Partially and briefly

The Pacific War, sometimes called the Asia–Pacific War,[35] was the theater of World War II that was fought in the Pacific and Asia. It was fought over a vast area that included the Pacific Ocean and islands, the South West Pacific, South-East Asia, and in China (including the 1945 Soviet–Japanese conflict).

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 as far as 19 September 1931 with the Japanese invasion of Manchuria.[36] However, it is more widely accepted[j][38] that the Pacific War itself began on 7/8 December 1941, when Japan invaded Thailand and attacked the British colonies of Malaya, Singapore, and Hong Kong as well as the United States military and naval bases in Hawaii, Wake Island, Guam and the Philippines.[39][40][41]

The Pacific War saw the Allies pitted against Japan, the latter briefly aided by Thailand and to a much lesser extent by the Axis allied Germany and Italy. The war culminated in the atomic bombings of Hiroshima and Nagasaki, and other large aerial bomb attacks by the Allies, accompanied by the Soviet declaration of war and invasion of Manchuria on 9 August 1945, resulting in the Japanese announcement of intent to surrender on 15 August 1945. The formal surrender of Japan ceremony took place aboard the battleship USS Missouri in Tokyo Bay on 2 September 1945. After the war, Japan lost all rights and titles to its former possessions in Asia and the Pacific, and its sovereignty was limited to the four main home islands.[42] Japan's Shinto Emperor was forced to relinquish much of his authority and his divine status through the Shinto Directive in order to pave the way for extensive cultural and political reforms.[43]


Names for the war

Generalissimo Chiang Kai-shek, Allied Commander-in-Chief in the China theatre from 1942 to 1945

In Allied countries during the war, the "Pacific War" was not usually distinguished from World War II in general, or was known simply as the War against Japan. In the United States, the term Pacific Theater was widely used, although this was a misnomer in relation to the Allied campaign in Burma, the war in China and other activities within the Southeast Asian Theater.

Japan used the name Greater East Asia War (大東亜戦争, Dai Tō-A Sensō), as chosen by a cabinet decision on 10 December 1941, to refer to both the war with the Western Allies and the ongoing war in China. This name was released to the public on 12 December, with an explanation that it involved Asian nations achieving their independence from the Western powers through armed forces of the Greater East Asia Co-Prosperity Sphere.[44] Japanese officials integrated what they called the Japan–China Incident (日支事変, Nisshi Jihen) into the Greater East Asia War.

During the Allied military occupation of Japan (1945–52), these Japanese terms were prohibited in official documents, although their informal usage continued, and the war became officially known as the Pacific War (太平洋戦争, Taiheiyō Sensō). In Japan, the Fifteen Years' War (十五年戦争, Jūgonen Sensō) is also used, referring to the period from the Mukden Incident of 1931 through 1945.


Political map of the Asia-Pacific region, 1939
Generalissimo Chiang Kai-shek and General Joseph Stilwell, Allied Commander-in-Chief in the China theatre from 1942–1945

The Axis states which assisted Japan included the authoritarian government of Thailand, which quickly formed a temporary alliance with the Japanese in 1941, as the Japanese forces were already invading the peninsula of southern Thailand. The Phayap Army sent troops to invade and occupy northeastern Burma, which was former Thai territory that had been annexed by Britain much earlier. The official policy of the US government is that Thailand was not an ally of the Axis, and that the United States was not at war with Thailand. The policy of the US government ever since 1945 has been to treat Thailand not as a former enemy, but rather as a country which had been forced into certain actions by Japanese blackmail, before being occupied by Japanese troops. Thailand has been treated by the United States in the same way as such other Axis-occupied countries as Belgium, Czechoslovakia, Denmark, Greece, Norway, Poland, and the Netherlands.

Also involved were the Japanese puppet states of Manchukuo and Mengjiang (consisting of most of Manchuria and parts of Inner Mongolia respectively), and the collaborationist Wang Jingwei regime (which controlled the coastal regions of China). In preparation for the war against the United States, which would be decided at sea and in the air, Japan increased its naval budget as well as putting large formations of the Army and its attached air force under navy command. While formerly the IJA consumed the lion's share of the state's military budget due to the secondary role of the IJN in Japan's campaign against China (with a 73/27 split in 1940), from 1942 to 1945 there would instead be a roughly 60/40 split in funds between the army and the navy.[45]

Japan conscripted many soldiers from its colonies of Korea and Formosa (Taiwan). To a small extent, some Vichy French, Indian National Army, and Burmese National Army forces were active in the area of the Pacific War. Collaborationist units from Hong Kong (reformed ex-colonial police), the Philippines, Dutch East Indies (the PETA) and Dutch Guinea, British Malaya and British Borneo, Inner Mongolia and former French Indochina (after the overthrow of the Vichy French regime) as well as Timorese militia also assisted Japanese war efforts.

Germany and Italy both had limited involvement in the Pacific War. The German and the Italian navies operated submarines and raiding ships in the Indian and Pacific Oceans. The Italians had access to "concession territory" naval bases in China, while the Germans did not. After Japan's attack on Pearl Harbor and the subsequent declarations of war, both navies had access to Japanese naval facilities.

The major Allied participants were the United States, China, the United Kingdom (including the armed forces of British India, the Fiji Islands, Samoa, etc.), Australia, the Commonwealth of the Philippines, the Netherlands (as the possessor of the Dutch East Indies and the western part of New Guinea), New Zealand, and Canada, all of whom were members of the Pacific War Council.[46] Mexico, Free France and many other countries also took part, especially forces from other British colonies.

The Soviet Union fought two short, undeclared border conflicts with Japan in 1938 and 1939, then remained neutral until August 1945, when it joined the Allies and invaded the territory of Manchukuo, China, Inner Mongolia, the Japanese protectorate of Korea and Japanese-claimed territory such as South Sakhalin.


The Pacific War Council as photographed on 12 October 1942. Pictured are representatives from the United States (seated), China, the United Kingdom, Australia, Canada, the Netherlands, New Zealand, and the Philippine Commonwealth.

Between 1942 and 1945, there were four main areas of conflict in the Pacific War: China, the Central Pacific, South-East Asia and the South West Pacific. US sources refer to two theaters within the Pacific War: the Pacific theater and the China Burma India Theater (CBI). However these were not operational commands.

In the Pacific, the Allies divided operational control of their forces between two supreme commands, known as Pacific Ocean Areas and Southwest Pacific Area.[47] In 1945, for a brief period just before the Japanese surrender, the Soviet Union and its Mongolian ally engaged Japanese forces in Manchuria and northeast China.

The Imperial Japanese Navy did not integrate its units into permanent theater commands. The Imperial Japanese Army, which had already created the Kwantung Army to oversee its occupation of Manchukuo and the China Expeditionary Army during the Second Sino-Japanese War, created the Southern Expeditionary Army Group at the outset of its conquests of South East Asia. This headquarters controlled the bulk of the Japanese Army formations which opposed the Western Allies in the Pacific and South East Asia.

Other Languages
bosanski: Rat na Pacifiku
Deutsch: Pazifikkrieg
Esperanto: Pacifika Fronto
한국어: 태평양 전쟁
hrvatski: Rat na Pacifiku
Bahasa Indonesia: Perang Pasifik
Basa Jawa: Perang Pasifik
Lëtzebuergesch: Pazifikkrich
Bahasa Melayu: Perang Pasifik
日本語: 太平洋戦争
oʻzbekcha/ўзбекча: Tinch okeanidagi urush
slovenčina: Vojna v Pacifiku
slovenščina: Vojna za Tihi ocean
српски / srpski: Рат на Пацифику
srpskohrvatski / српскохрватски: Rat na Pacifiku