Combined operations

Not to be confused with Combined arms, the integrated use of multiple combat arms (infantry, armor, artillery, etc.).
For the department of the British War Office during World War II or the Rhodesian headquarters, see Combined Operations Headquarters and Combined Operations (Rhodesia).
U.S. Army and Iraqi Army soldiers boarding helicopters during the Iraq War, 2009

In current military use, combined operations are operations conducted by forces of two or more allied nations acting together for the accomplishment of a common strategy, a strategic and operational and sometimes tactical cooperation. Interaction between units and formations of the land, naval and air forces, or the cooperation between military and civilian authorities in peacekeeping or disaster relief operations is known as joint operations or interoperability capability.