text: Chapter 1
  Armies, Corps, and Divisions
  Chapter 1 establishes the roles of theater armies, field armies, corps, and divisions
  within the context of a larger joint force. This chapter begins by describing the strategic
  environment, including threats, the Army’s strategic roles, and the competition
  continuum. Next, this chapter summarizes how Army forces contribute to joint and
  multinational operations through unified land operations. This is followed by a brief
  description of these formations, including the roles they perform in operations. Then
  this chapter describes operational and administrative chains of command. This chapter
  concludes with a description of operational areas.
  LANDPOWER FOR THE JOINT FORCE
  1-1. The primary purpose of the Army is to provide sustained landpower to the joint force. Landpower is
  the ability—by threat, force, or occupation—to gain, sustain, and exploit control over land, resources, and
  people (ADP 3-0). While landpower can, and often is, tailored to any circumstance or operation, the Army
  exists to fight and win wars on terms favorable to the United States and its allies. Army forces are organized,
  manned, equipped, and trained for this purpose. While prevailing in large-scale ground combat is the primary
  mission of Army forces, Army forces are often called upon to support the joint force across three additional
  strategic roles: shaping operational environments, preventing conflict, and consolidating gains. They do this
  during competition, crisis, and conflict. The echelons above brigade remain indispensable to these operations.
  Joint interdependence is the purposeful reliance by one Service on another Service’s capabilities to maximize
  the complementary and reinforcing effects of both (JP 3-0).
  1-2. Armies, corps, and divisions provide the joint force flexible, tailorable formations and headquarters
  capable of managing crises and conducting large-scale ground combat. These echelons provide combatant
  commanders with credible forces that possess the technical and tactical capabilities to conduct successful
  operations across the full range of military operations. They provide the ability to conduct prompt and
  sustained operations; sustain Army and joint forces; consolidate gains; and enable unified action partners to
  interact with, secure, or control populations.
  1-3. Armies, corps, and divisions, acting separately or in concert with each other as part of a joint and
  multinational force, provide the capability to plan, prepare, execute, and assess joint and multinational
  operations. They combine all elements of national, multinational, and joint power in the conduct of
  operations. In addition to providing trained and credible Army forces, these echelons may perform one of six
  roles during the conduct of operations:
  * Army Service component command (ASCC).
  * Theater joint force land component command.
  * Joint task force (JTF).
  * Joint force land component command.
  * ARFOR.
  * Tactical command.
  1-4. Armies, corps, and divisions provide headquarters with the required expertise and capabilities to
  conduct continuous multi-domain operational preparation of the environment, rapidly converge effects from
  across multiple domains against enemy forces, synchronize that convergence across the depth and breadth of
  the extended battlefield, and ensure that overwhelming combat power is generated at the decisive time and
  place against enemy forces. This expertise at multiple echelons provides options to compete below the