Pacific Ocean theatre of World War II

The Pacific Ocean theatre, during World War II, was a major theatre of the war between the Allies and Japan. It was defined by the Allied powers' Pacific Ocean Area command, which included most of the Pacific Ocean and its islands, while mainland Asia was excluded, as were the Philippines, the Dutch East Indies, Borneo, Australia, most of the Territory of New Guinea and the western part of the Solomon Islands.

It officially came into existence on March 30, 1942, when US Admiral Chester Nimitz was appointed Supreme Allied Commander Pacific Ocean Area. In the other major theatre in the Pacific region, known as the South West Pacific theatre, Allied forces were commanded by US General Douglas MacArthur. Both Nimitz and MacArthur were overseen by the US Joint Chiefs and the western Allies Combined Chiefs of Staff (CCoS).

Most Japanese forces in the theatre were part of the Combined Fleet (聯合艦隊) of the Imperial Japanese Navy (IJN), which was responsible for all Japanese warships, naval aircraft and marine infantry infantry units. The Rengō Kantai was led by Admiral Isoroku Yamamoto, until he was killed in an attack by U.S. fighter planes in April 1943. Yamamoto was succeeded by Admiral Mineichi Koga (1943–44) and Admiral Soemu Toyoda (1944–45). The General Staff  (参謀本部) of the Imperial Japanese Army  was responsible for Imperial Japanese Army (IJA) ground and air units in Southeast Asia and the South Pacific. The IJN and IJA did not formally utilize joint/combined staff at the operational level, and their command structures/geographical areas of operations overlapped each other and those of the Allies.

In the Pacific Ocean theatre, Japanese forces fought primarily against the United States Navy and US Marine Corps. The United Kingdom, New Zealand,  Australia, Canada and other Allied nations also contributed forces.

Major campaigns and battles

 * Central Pacific Theater
 * Attack on Pearl Harbor 7 December 1941
 * Battle of Wake Island 7–23 December 1941
 * Doolittle Raid 18 April 1942
 * Battle of the Coral Sea 4-8 May 1942
 * Battle of Midway 4–6 June 1942
 * Gilbert and Marshall Islands campaign 1943–44
 * Makin Island raid 17–18 August 1942
 * Battle of Tarawa 20 November 1943
 * Battle of Kwajalein 1 February 1944
 * Battle of Eniwetok 17 February 1944
 * Attack on Truk Island 17-18 February 1944
 * Mariana and Palau Islands campaign 1944
 * Battle of Saipan 15 June 1944
 * Battle of the Philippine Sea 19–21 June 1944
 * Battle of Guam 21 July 1944
 * Battle of Tinian 24 July 1944
 * Battle of Peleliu 15 September 1944
 * Battle of Angaur 17 September 1944
 * Battle of Iwo Jima 19 February 1945
 * Battle of Okinawa 1 April 1945
 * North Pacific Theater
 * Aleutian Islands Campaign 1942–43
 * Battle of the Komandorski Islands 26 March 1943