South West Pacific theatre of World War II



The South West Pacific theatre, during World War II, was a major theatre of the war between the Allies and Japan. It included the Philippines, the Dutch East Indies (except for Sumatra), Borneo, Australia and its mandate Territory of New Guinea (including the Bismarck Archipelago) and the western part of the Solomon Islands. This area was defined by the Allied powers' South West Pacific Area (SWPA) command.

In the South West Pacific theatre, Japanese forces fought primarily against the forces of the United States and Australia. New Zealand, the Netherlands (mainly the Dutch East Indies), the Philippines, United Kingdom, and other Allied nations also contributed forces.

Allied command
The U.S. General Douglas MacArthur had been in command of the American forces in the Philippines in what was to become the South West Pacific theatre, but was then part of a larger theatre that encompassed the South West Pacific, the South East Asian mainland (including Indochina and Malaya) and the North of Australia, under the short lived American-British-Dutch-Australian Command (ABDACOM). Shortly after the collapse of ABDACOM, supreme command of the South West Pacific theatre passed to MacArthur who was appointed Supreme Allied Commander South West Pacific Area on 30 March 1942. In the other major theatre in the Pacific region, known as the Pacific Ocean theatre, Allied forces were commanded by US Admiral Chester Nimitz. Both MacArthur and Nimitz were overseen by the US Joint Chiefs and the western Allies Combined Chiefs of Staff (CCoS).

Japanese command
Most Japanese forces in the theatre were part of the Southern Expeditionary Army (南方軍), which was formed on November 6, 1941, under General Hisaichi Terauchi (also known as Count Terauchi). The Nanpo gun was responsible for Imperial Japanese Army (IJA) ground and air units in Southeast Asia and the South Pacific. The Combined Fleet (聯合艦隊) of the Imperial Japanese Navy (IJN) was responsible for all Japanese warships, naval aviation units and marine infantry units. As the Japanese military did not formally utilize joint/combined staff at the operational level, the command structures/geographical areas of operations of the Nanpo gun and Rengō Kantai overlapped each other and those of the Allies.

Major campaigns in the theatre

 * Battle of the Philippines (1941–42)
 * Battle of Bataan
 * Battle of Corregidor
 * Dutch East Indies campaign, 1941–42
 * Battle of Badung Strait 19–20 February 1942
 * Battle of the Java Sea 27 February 1942
 * Battle of Sunda Strait 28 February – 1 March 1942
 * Second Battle of the Java Sea 1 March 1942
 * Solomon Islands campaign 1943–45
 * Battle of Kula Gulf 6 July 1943
 * Battle of Kolombangara 13 July 1943
 * Battle of Vella Gulf 6–7 August 1943
 * Naval Battle of Vella Lavella 6–7 October 1943
 * Battle of Empress Augusta Bay 2 November 1943
 * Battle of Cape St. George 25 November 1943
 * New Guinea campaign, 1942–45
 * Battle of the Coral Sea 4–8 May 1942
 * Kokoda Track campaign 1942
 * Battle of Buna-Gona 1942
 * Battle of the Bismarck Sea 2 March 1943
 * Landing at Nassau Bay 1943
 * Salamaua-Lae campaign 1943
 * Huon Peninsula campaign 1943
 * New Britain campaign 26 December 1943
 * Admiralty Islands campaign 29 February 1944
 * Aitape-Wewak campaign 22 April 1944
 * Invasion of Hollandia 22 April 1944
 * Battle of Biak 27 May 1944
 * Battle of Noemfoor 2 July 1944
 * Battle of Morotai 15 September 1944
 * Battle of Timor 1942–43
 * Philippines campaign (1944–45)
 * Battle of Leyte Gulf 20 October 1944
 * Borneo campaign (1945)