text: Chapter 4
  Corps Roles, Functions, and Organizations
  [The corps] can engage on an extended front and can carry on a battle until a decision is
  reached… In actions of long duration, the divisional units are relieved by fresh units; but
  the corps remains until a decision is reached or the strategical plan is changed.
  A Manual for Commanders of Large Units
  This chapter discusses the roles and responsibilities the corps can fulfill across the
  competition continuum. Then it describes the corps headquarters capabilities,
  limitations, and organizations to exercise command and control in a variety of roles.
  This is followed by a description of organizations typically commanded by a corps.
  The chapter concludes with a section on how the corps is employed across the range
  of military operations.
  CORPS OVERVIEW
  4-1. The corps is the most versatile echelon above brigade due to its requirement to potentially operate at
  the tactical and operational levels of warfare. While it is organized, manned, trained, and equipped 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 JTF, the corps will serve as
  the ARFOR. The corps can also serve as the JFLCC when properly augmented with joint and multinational
  personnel. If the corps is uncommitted to specific combatant commander requirements, it focuses on building
  and sustaining readiness to prevail in large-scale ground combat.
  4-2. The characteristics distinguishing corps operations from those of the division are scope and scale.
  Instead of focusing on tactical maneuver, the corps focuses on shaping conditions for its divisions by use of
  its assets, enablers, and leveraging joint capabilities. Command at this echelon requires operational art,
  tactical expertise, and complementary employment of Army and joint capabilities. Joint capabilities are the
  primary means available to the corps commander for setting conditions and shaping the environment for
  division operations. The ability to execute deliberate and dynamic targeting is a critical capability of the corps
  regardless of its assigned role. Likewise, the corps ability to comply with the theater airspace control plan,
  process subordinate unit airspace plans, and integrate organic and supporting airspace users is essential to
  executing operations in the air domain.
  ROLES AND FUNCTIONS
  4-3. The corps headquarters has specific roles and performs specific functions. They include acting as the—
  * Senior Army tactical formation in large-scale combat, commanding two to five Army divisions
  together with supporting brigades and commands.
  * ARFOR (with augmentation) within a joint force for campaigns and major operations when a field
  army is not present.
  * JTF headquarters (with significant augmentation) for crisis response and limited contingency
  operations.
  * Joint force land component (with significant augmentation) commanding U.S. Army, Marine
  Corps, and multinational divisions together with supporting brigades and commands when a field
  army is not present.