text: Army Operations Overview
  ARMY COMPONENTS
  2-36. By law, the Army is structured with one Regular Army and two Reserve Components: the Army
  Reserve; and the Army National Guard. The Regular Army consists of professional Soldiers in units of all
  types necessary for prompt employment of land power. The Army National Guard is comprised of citizen
  Soldiers. It performs both a state military mission under Title 32, United States Code, which may include
  training for federal missions, and an operational reserve mission for the Regular Army under Title 10, United
  States Code. The unit structure and equipment in the Army National Guard is identical to that used in the
  Regular Army. The Army Reserve is also comprised of citizenSoldiers, but it performs only a federal military
  mission under Title 10, United States Code, as individuals or units. The Army Reserve provides individual
  augmentees for headquarters and units, half of the Army’s sustaining units, and one-fourth of the Army’s
  mobilization base expansion capability. (See ADP 1 for more information on Army components.)
  2-37. The Army JAG Corps relies heavily on the Reserve and National Guard Components to provide legal
  services to the Army. JAG Corps elements and personnel in theArmy Reserve and Army National Guard are
  vital to the JAG Corps’ ability to support rear-detachment operations, mobilization of Guard and Reserve
  units, forward deployment of units to a theater of operations, and direct support to large-scale combat
  operations. Army doctrine, as well as JAG Corps doctrine, applies to all components. (See Chapter 3,
  Appendix A, and Appendix B for further discussion of the structure and support of the JAG Corps Army
  Reserve and Army National Guard Components.)
  ARMY ECHELONS ANDUNITS
  2-38. As discussed earlier in the chapter, the Army provides the CCMDs a mix of headquarters, units, and
  capabilities. These elements and capabilities conduct joint operations as part of the theater campaign plan
  (See FM 3-0 for more information on Army contributions to CCMDs.)
  2-39. Army headquarters and commanders may serve in various roles in the joint force. Many Army
  commanders hold multiple roles simultaneously, such as land forces component commander, Army service
  component commander, senior Army Forces (known as ARFOR) commander, and joint forces commander.
  All joint task forces that include Army forces have an ARFOR, the Army component and senior Army
  headquarters of all forces assigned or attached to a combatant command, subordinate joint force, joint
  functional command, or multinational command (FM 3-94). The designated roles of the Army commander
  are significant for JALS personnel because roles determine the commander’s legal authorities and
  responsibilities within the joint force. JALS personnel must also pay close attention to the relationships and
  responsibilities assigned to supported commands because they dictate the extent of legal support required to
  adjacent and attached units. (See FM 3-94 for more information theater army, corps, and division operations.)
  THEATER OF FIELD ARMY
  2-40. The senior Army headquarters in the CCMD’s area of responsibility is the theater army. This echelon
  is comprised of the commander, staff, and all Army forces assigned to the CCMD. It is responsible for the
  command of forces and direction of operations (operational responsibility) and equipping, sustaining,
  training, discipline, and personnel matters (administrative responsibilities) of assigned Army units. The
  composition of the theater army will vary based on the needs of CCMD. A field army headquarters is the
  Army component assigned to a subordinate unified command. The field army headquarters is staffed and
  equipped to perform three functions: Army component and ARFOR for a subordinate unified commander,
  joint force land component headquarters (with augmentation) for large-scale combat operations, or joint task
  force headquarters (with augmentation) for crisis response and limited contingency operations. Eighth Army,
  for example, is a field army currently assigned to United States Forces Korea, a subordinate unified command
  under United States Indo-Pacific Command. (See FM 3-94 for more information on armies.)
  CORPS
  2-41. The corps is the most versatile echelon above brigade due to its ability to operate at both the tactical
  and operational levels. While it is organized, staffed, trained, and equipped to fight as a tactical formation,
  the corps may be called upon to become a joint and multinational headquarters for conducting operations.
  When operating as the senior Army headquarters under a joint task force (known as JTF), the corps will serve