text: Operational Art and Science
  * Secure and maintain lines of communications with Army and host-nation forces.
  * Manage movement of subordinate forces and coordinate across the formation for movement of
  sustainment units.
  2-87. At the tactical level, sustainment remains the key to freedom of action. Properly integrated, the support
  provided by sustainment units allows formations to maneuver, concentrate their capabilities, and adjust their
  task organization quickly. If poorly coordinated, sustainment becomes a major contributor to loss of
  momentum and inadequate operational reach. Staffs give particular attention to integrating their sustainment
  units’ requirements into their concept of operations. This includes careful selection and security of support
  areas in their AOs, and planning for their displacement based upon adjustments to the tactical AO. This
  displacement planning is based on movement, general engineering, security, and protection capabilities. The
  displacement of the support area normally entails more time and effort than shifting a subordinate formation.
  Main and Supporting Efforts
  2-88. The final component of the operational framework is establishing main and supporting efforts.
  Commanders designate main and supporting efforts to establish clear priorities of support and resources
  among subordinate units. The main effort is a designated subordinate unit whose mission at a given point in
  time is most critical to overall mission success (ADP 3-0). It is usually weighted with the preponderance of
  combat power. Typically, commanders shift the main effort one or more times during execution.
  2-89. Designating a main effort temporarily prioritizes resource allocation. When commanders designate a
  unit as the main effort, it receives priority of support and resources to maximize combat power. However,
  the higher echelon commander may withhold certain resources from the main effort to ensure their
  availability for the decisive operations. This carries a certain amount of risk that the commander must balance
  between current operations, the upcoming decisive operation, and possible future missions.
  2-90. Commanders may designate a unit conducting a shaping operation as the main effort until the decisive
  operation commences. However, the unit with primary responsibility for the decisive operation then becomes
  the main effort upon the execution of the decisive operation.
  2-91. A supporting effort is a designated subordinate unit with a mission that supports the success of the
  main effort (ADP 3-0). Commanders resource supporting efforts with the minimum assets necessary to
  accomplish the mission. Because they are not resourced the same as the main effort, it is critical that higher
  echelon commanders clearly identify the task and purpose for their operations so that they do not create a
  situation that could potentially endanger the success of the main effort or the decisive operation.
  COMMAND AND CONTROL IN MULTIPLE DOMAINS
  2-92. Through command and control, Army forces converge effects from all domains (land, air, maritime,
  space, and cyberspace), and the information environment and the electromagnetic spectrum, to accomplish
  missions. Convergence involves the continuous integration of capabilities from multiple domains, the
  electromagnetic spectrum, and the information environment, to create multiple dilemmas for the enemy. To
  converge effects from all domains, Army forces must understand the authorities, processes, procedures, and
  time it takes to receive effects from other domains and for Army forces to create effects in those domains.
  To converge combat power throughout operations, Army echelons serving as a functional or Service
  component to a joint force must integrate into various theater command and control processes and procedures
  addressed in these joint publications: JP 3-12, JP 3-13, JP 3-14, JP 3-30, JP 3-31, JP 3-32, and JP 3-52.
  2-93. Liaison and coordination are vital to Army headquarters in gaining access to capabilities and effects
  from other components of the joint force. Liaison is that contact or intercommunication maintained between
  elements of military forces or other agencies to ensure mutual understanding and unity of effort. Most
  commonly used for establishing and maintaining close communications, liaison activities enables direct face-
  to-face communications between commands and with unified action partners. Liaison activities augment the
  commander’s ability to integrate and converge effects from multiple domains into the concept of operations.
  Liaison activities ensure—
  * Cooperation and understanding among commanders and staffs of different headquarters.
  * Coordination to achieve unity of effort.