text: Chapter 3
  Religious Support by Echelon
  ECHELONS OF COMMAND
  3-1. The Army provides to geographic combatant commanders (GCCs) a mix of headquarters, units, and
  capabilities in an echeloned array designed toward specific missions or functions. A force package may
  consist of light, medium, and heavy forces; it can blend regular Army, Army National Guard, and U.S. Army
  Reserve units and Soldiers. Combat power includes all capabilities provided by unified action partners which
  are integrated in a multi-domain approach to achieve unity of effort across the ROMO. Military power cannot,
  by itself, restore or guarantee a stable peace or an agreeable political solution. The exercise of military power
  sets the conditions that enable other instruments of national power to exert their contributing influence.
  3-2. Army forces need versatile and deployable headquarters suited for contingencies and protracted
  operations. To provide higher echelon mission command, the Army fields a mix of tactical and operational
  headquarters able to function as land force, joint, multinational and Service component command
  headquarters. There are five general echelons of commands within a GCC’s area of responsibility.
  3-3. The theater army, or ASCC, serves as the senior Army echelon command of a GCC’s area of
  responsibility. It includes the Service component commander and all Army forces assigned to a GCC. Its
  operational responsibilities include command of forces, direction of operations, and control of assigned AOs.
  Its administrative responsibilities encompass Service-specific requirements for equipping, sustaining,
  training, unit readiness, discipline, and personnel matters. (See FM 3-0 for a discussion of support to other
  Services.) Additional forces might be aligned or attached to the theater army in order to custom tailor the
  capabilities required to support the GCC. These could include but are not limited to theater level sustainment
  command, military intelligence brigade-theater, expeditionary sustainment command, civil affairs brigade,
  medical command, air and missile defense command, military police command, psychological operations
  brigade, engineering command, chemical, biological, radiological, and nuclear (CBRN) brigade, and theater
  aviation command.
  3-4. Large-scale combat operations might require a corps headquarters to function as a tactical land
  headquarters under a joint or multinational land component command. As such, the corps commands Army
  and multinational forces in campaigns and major operations. Operationally, corps conduct offensive,
  defensive, and stability tasks with operational control of two or more divisions and a variety of supporting
  brigades, tactical control over various multinational units and U.S. Marine Corps units, and it is supported
  by various theater sustainment organizations. Corps operations shape an OE and set the conditions for tactical
  actions by divisions and lower echelons. Administratively, a corps provides administrative and logistics
  support to all assigned Army forces as specified by the theater army. (See FM 3-0 for a discussion of support
  from the theater army.)
  3-5. A division’s primary role is as a tactical headquarters commanding brigades in decisive action. The
  division executes the tasks assigned by its higher headquarters as both a formation and a headquarters during
  large-scale combat operations. Operationally, the division conducts shaping operations within the division
  AO, task-organizes and employs brigade combat teams (BCTs) and multifunctional and functional brigades,
  integrates and synchronizes operations of those same brigades, masses effects at decisive points, allocates
  resources and sets priorities, and leverages joint capabilities. When a division receives attachments, that
  division assumes administrative control of those units, to include logistics, medical and administration.
  3-6. A BCT is the Army’s primary combined arms, close-combat force. BCTs maneuver against, close
  with, and destroy the enemy. They are the principle ground maneuver units of a division. There are three
  types of BCTs: armored, infantry, and Stryker. Each BCT has scalable organic capabilities across the
  warfighting functions.