text: Operations During Armed Conflict
  6-208. Spoiling attacks and counterattacks can be used to disrupt enemy forces and prevent them from
  massing combat power or exploiting success in the main battle area. Future operations cells conduct
  contingency branch and sequel planning to counter potential enemy penetrations of the main battle area,
  typically by repositioning forces and establishing decision points for committing the reserve.
  RESERVE
  6-209. Commanders base the size of their reserve on the level of uncertainty about the enemy force’s
  capabilities and intentions. A commander’s concept of operations describes the size, composition, location,
  and priorities of planning for the reserve. The more uncertainty that exists, the larger the reserve is. The
  purpose of the reserve during the defense is to maintain a hedge against uncertainty and counter enemy
  success, usually by blocking a penetration or enveloping it from a flank. When planning a defense,
  commanders cannot typically be strong everywhere, and therefore they accept risk about unlikely enemy
  courses of action. A reserve mitigates the risk the commander assumes. Commanders may use reserves to
  counterattack enemy vulnerabilities, such as exposed flanks or support units, or to defeat isolated parts of the
  enemy forward echelon. In some cases, a commander must use the reserve to reinforce battle positions in the
  main battle area to hold critical terrain, block penetrating enemy forces, or to react to threats against the
  division or corps rear area. Units position their reserve force for maximum flexibility.
  6-210. Commanders determine the reserve’s planning priorities based on their estimate of the situation.
  Commanders of brigades or larger formations normally retain about one quarter of their force in reserve,
  though the percentage depends on the scheme of maneuver and the commander’s level of uncertainty. Higher
  levels of uncertainty require a larger reserve.
  6-211. Timing is critical to counterattacks. Commanders must anticipate the circumstances requiring
  commitment of their reserve and rehearse its commitment to the main battle area. Rehearsals help validate
  the reserve’s response plan and increase the speed with which it can respond. Commanders make the decision
  to commit a reserve promptly, with sound understanding of the movement and deployment timelines from
  its assembly area to the main battle area in existing terrain and weather conditions. If committed too soon,
  reserves may not have the desired effect or be in a good position for commitment against a more dangerous
  situation later. Committed too late, the reserve may not be able to influence the situation enough to meet the
  overall intent. Movement control and air defense in the rear area is vital to getting the reserve into the battle
  on time and in good order.
  6-212. Reserves may be air or ground maneuver units or a combination of the two. They should be
  task-organized with combined arms capabilities and given priority for the employment of joint capabilities.
  Commanders take the strengths and weaknesses of the reserve into account and plan accordingly. For
  example, employing an air assault force provides a formation that can respond rapidly to a threatened area or
  rapidly threaten an enemy flank after seizing key terrain. Once committed, however, it has limited mobility
  and sustainment capabilities.
  6-213. The mobility and lethality of attack aviation makes it one of the most responsive and effective types
  of reserves. It can rapidly counterattack enemy armored penetrations. Despite its effectiveness, attack
  aviation should never be the only reserve element due to the potential impacts of weather and the risk incurred
  by not having enough aviation available for other critical roles, such as enabling security area operations.
  6-214. Once commanders commit a reserve, they immediately begin to constitute another one from
  uncommitted forces or from forces in less threatened areas. When selecting the new reserve, commanders
  consider what capabilities would be most effective in the situation and the likely locations where it would be
  employed.
  REAR OPERATIONS DURING DEFENSIVE OPERATIONS
  6-215. Rear operations maintain freedom of action in the security and main battle areas and prevent
  culmination. The rear command post enables this freedom of action by planning and directing sustainment,
  conducting terrain management, providing movement control, and providing area security of the rear area.
  Rear operations ensure prompt delivery of commodities in high demand during defensive operations,
  particularly ammunition. Depending on the enemy situation, commanders commit maneuver units to secure
  rear operations, although all forces conducting rear operations must maintain local security and conduct