Theater of operations (military)

In the context of military usage, a theater of operations is an geographic area under, in most cases, a unified command structure to which all arms of service report. For example, in the Second World War, there was a European Theater, under which the Italian theater eventually came. There was a Mediterranean theater. Against Japan, there was a China-Burma-India theater that made geographic sense, but the personalities of Douglas MacArthur and Chester Nimitz, as well as Army-Navy rivalry, caused a split between MacArthur's Southwest Pacific Area and Nimitz's Pacific Ocean and Pacific Ocean Areas.

U.S. Unified Combatant Commands are define on geographic or functional lines. The geographic UCCs reasonably correspond to theaters of operations:

• United States Northern Command (North America)
• United States Southern Command (Latin America)
• United States Central Command (Middle East and Southwest Asia)
  • Multi-National Force-Iraq
  • International Security Assistance Force (Afghanistan)
• United States European Command
  • United States Africa Command
• United States Pacific Command (remainder of Asia and the Pacific)
  • United States Forces Korea a "unified subcommand"