text: Chapter 1
  1-85. During competition, the division is capable of fulfilling the ARFOR role for operations of limited scope
  and duration. Under such conditions, it may also form the nucleus for a very small-scale JTF or JFLCC,
  although it would require significant joint force augmentation. The division can conduct multi-service
  training or administration and they can coordinate non-combat activities when serving in a joint role, but they
  cannot effectively direct joint forces in combat.
  1-86. The division normally focuses on operational responsibilities. Unless the division is serving as the
  ARFOR, a higher echelon normally retains ADCON for all units that are not organic, assigned, or attached
  to the division. However, in certain instances, the division commander may be designated the deputy ARFOR
  with prescribed responsibilities when the situation warrants. (See Chapter 5 for a detailed description of the
  division. For additional information on the role of the ARFOR, see Appendix B and ATP 3-91.)
  OPERATIONAL AND ADMINISTRATIVE CHAINS OF COMMAND
  1-87. Echelons above brigade exercise a mixture of command relationships over subordinate forces. As
  described in JP 1, the President and Secretary of Defense exercise authority and control of the armed forces
  through two distinct branches of the chain of command. One branch runs from the President, through the
  Secretary of Defense, to the combatant commanders for missions and forces assigned to combatant
  commands. This is the operational chain of command or OPCON. For purposes other than the operational
  direction of combatant commands, the chain of command runs from the President to the Secretary of Defense,
  to the secretaries of the Military Departments, and, as prescribed by the secretaries to the service commanders
  of U.S. forces. Each Military Department operates under the authority, direction, and control of the secretary
  of that Military Department. This is the ADCON of forces.
  1-88. At every echelon, commanders are responsible for the operations and administration of their units and
  all Army units assigned or attached to them. In joint commands, OPCON and ADCON of forces becomes
  apparent. The joint commander exercises OPCON over all forces assigned to the command, and the senior
  Army headquarters assigned to that command is typically responsible for executing the ADCON
  responsibilities as the ARFOR for that command. The theater army provides essential support through
  sustainment and medical commands as supporting headquarters to units OPCON to a supported JTF,
  fulfilling its responsibility to execute ADCON responsibilities for the combatant command. It reduces the
  workload imposed on the operational headquarters by shifting sustainment, support to other Services, and
  multinational and combatant command support activities requirements from the corps and division. Without
  it, the support requirements could overwhelm the ability of the corps and division to exercise effective
  operational command of their subordinate forces.
  OPERATIONAL CHAIN OF COMMAND
  1-89. The assignment of forces to the combatant commands comes from the Secretary of Defense in the
  Forces for Unified Commands memorandum. This memorandum is included in section III of the Global
  Force Management Implementation Guidance. These force assignments are documented in the Global Force
  Management Implementation Guidance assignment tables. These documents are maintained on the classified
  SIPRNET and require approved access in order to view them.
  1-90. There are three types of combatant commands:
  Global Force Management
  * Functional combatant commands have global
  Implementation Guidance
  responsibilities for U.S. military power, but do not have
  Guidance issued by the Secretary of
  an AOR.
  Defense that codifies the processes
  * GCC commands have a regional responsibility defined
  used by Department of Defense to
  by an AOR.
  execute Global Force Management.
  * Specified combatant commands (there are none The text in this document is updated
  currently) are established by the Secretary of the Defense in even fiscal years and the Force
  for a specific purpose and are normally composed of Assignment tables are updated every
  forces from a single department. fiscal year.
  Every combatant command has an ASCC. Table 1-1 lists eleven
  combatant commands and their associated ASCC. Unless stated otherwise, any mention of ASCCs in this
  manual refers to the theater armies assigned to GCCs.