text: Chapter 7
  headquarters and staff to facilitate joint integration specific to that JOA and the particular Army operations
  within it. A JOA is established for operations within an AOR that is specialized or limited in its scope or
  duration, and a JFC directs military operations as a joint task force (JTF).
  DESIGNATING A JOINT SECURITY AREA
  7-29. Within the JOA, the JFC designates numerous joint security areas (JSAs). In a maritime environment,
  JSAs can be separated by considerable distances, and they probably will not be with areas that are actively
  engaged in combat. A theater army headquarters or theater sustainment command (TSC) may be required to
  conduct theater sustainment operations from a single designated JSA or from multiple locations, depending
  on mission requirements. Army forces may also be designated to secure the JSA and critical intermediate
  staging bases. (See JP 3-10 for additional information on planning and execution of operations in the JSA.)
  ASSIGNING AN AREA OF OPERATIONS
  7-30. An AO is the operational area defined by a commander for land and maritime forces. The JFC assigns
  land areas of operations. The designation of subordinate AOs in a maritime environment enables freedom of
  action, maintains tempo, and maximizes available combat power. Larger island land masses may allow Army
  forces to operate with a contiguous AO, with the unit boundaries directly adjacent to each other. Smaller
  archipelagic island chains may require a noncontiguous AO and may even leave some islands within a
  designated AO completely unoccupied by friendly forces depending on the operational requirements and
  threat. Figure 7-2 illustrates a notional corps area of operations with significant maritime aspects.
  Figure 7-2. Notional corps area of operation with maritime aspects