ARMY FORCES IN A THEATER OF OPERATIONS
Section I. THEATER OF OPERATIONS
a. A theater (area) of war is that area of land, sea, and air that is, or may
become, involved directly in the conduct of war.
b. A theater (area) of operations (TO) is that portion of a theater (area) of war
necessary for military operations, either offensive or defensive, pursuant to an assigned
mission, and for the administration incident to such military operations.
c. The zone of interior (ZI) is that portion of the Continental United States
(CONUS) and its outlying states and possessions not included in a TO.
a. While it is possible for the forces of a single US Armed Service to establish
and operate a TO, US Forces normally execute their operational tasks as part of either a
joint task force, a unified command, or a combined command.
(1) A joint task force is a force composed of assigned or attached elements
of two or more services under the operational control of a single commander. It is
established when the mission to be accomplished has a specific limited objective, and it
is dissolved when the objective has been achieved.
(2) A unified command is a command composed of significant assigned
components of two or more Services, under the operational command of a single
commander, with a broad continuing mission. It is established by the President, through
the Secretary of Defense, with the advice and assistance of the Joint Chiefs of Staff, or,
when so authorized by the Joint Chiefs of Staff, by a commander of an existing unified
command established by the President.
NOTE: Operational command is a term that includes those functions of command
involving the composition of subordinate forces, the assignment of tasks, the
designation of objectives, and the authoritative direction necessary to accomplish the
mission. It does not include such matters as administration, discipline, internal
organization, and training, except when a subordinate commander requests assistance.
(The term is synonymous with OPERATIONAL CONTROL, but is uniquely applied to
the authority exercised by commanders at the unified command level.)