The Pacific Theater of Operations (PTO) is the term used in the United States for all military activity in the Pacific Ocean and the countries bordering it, in World War II. Pacific War is a more common name, around the world, for the broader conflict between the Allies and Japan, between 1937 and 1945.
Partly because of the nearly equal roles of the US Army and the US Navy in conducting war in the Pacific, but largely for domestic political reasons, there was not a single Allied or US commander for the theater(comparable to Eisenhower in the ETO). Indeed, the organizational structure was rather tangled, with the Joint Chiefs of Staff frequently required to be involved, and the Army and Navy commanders reporting to both the Secretary of the Navy and the Secretary of War. (No doubt the attendant difficulties helped motivate the formation of the Department of Defense in 1947.)
The two main Allied commanders in the PTO were Commander-in-Chief Pacific Ocean Areas, the title held by Admiral Chester Nimitz and Supreme Allied Commander South West Pacific Area1, General Douglas MacArthur (following termination of the short-lived ABDACOM, in early 1942.)
- At least initially in World War II, the official Japanese name for the war was Dai toua sensou (大東亜戦争, Greater East Asia War). This name was chosen by a cabinet decision on December 10, 1941, to refer to both the war with the United States and the ongoing war in China, which began with the China Incident (or Mukden Incident). The name was released to the public two days later, on December 12, with a government explanation that it referred to the motivation of Asian nations to achieve independence from the Western nations - it was not intented to set parameters for the battlefield. Soon after the start of the war with the USA, this term was prohibited in official documents, though some say its use continued.
- The war was from this point called Taiheiyo sensou (太平洋戦争) literally meaning the Pacific War. This latter term has been in use since that time.
- Less often, Jyugonen'sensou (十五年戦争 15 Year War) is used to refer to the war, beginning with the Japanese invasion of China in 1931 (also called the Sino-Japanese War) to the end of World War II in 1945. The term is used to highlight the rule of militarism over the years.
A theater of operations
The term "theater of operations" was defined in the [American] field manuals as the land and sea areas to be invaded or defended, including areas necessary for administrative activities incident to the military operations (chart 12). In accordance with the experience of World War I, it was usually conceived of as a large land mass over which continuous operations would take place and was divided into two chief areas-the combat zone, or the area of active fighting, and the communications zone, or area required for administration of the theater. As the armies advanced, both these zones and the areas into which they were divided would shift forward to new geographic areas of control.2
- Douglas MacArthur as Supreme Commander SWPA (http://www.archives.gov/research_room/federal_records_guide/ww2_allied_occupation_headquarters_rg331.html#331.34)88 Msg: through established channels (http://www.army.mil/cmh-pg/books/wwii/Sp1941-42/ench7.htm)
- Chapter VII: Prewar Army Doctrine for Theater (http://history.amedd.army.mil/booksdocs/wwii/orgadmin/org_admin_wwii_chpt7.htm)
- http://ask.c.u-tokyo.ac.jp/~yasutomi/private2/home/glossary.html (Some English translations for Japanese terms.)