text: Chapter 5
  striking force. The commander uses the fixing force to hold attacking enemy forces in position, to help
  channel attacking enemy forces into ambush areas, and to retain areas from which to launch the striking force.
  SUSTAINMENT PREPARATION FOR MOBILE DEFENSE
  5-216. The main battle area is where corps and division commanders want to destroy an attacking enemy
  force by employing a combination of fixing and striking forces. The sustainment commander supports main
  battle forces by pre-positioning tailored supplies to expedite the construction of countermobility and
  protective positions, forward positioning maintenance and recovery assets to regenerate combat power, and
  expediting personnel fills and returns-to-duty to reconstitute fighting formations.
  5-217. The fixing force typically consists of one-third to one-half of the defender’s combat power. It shapes
  the enemy penetration or contains the enemy’s advance through a combination of an area defense and a
  delaying action to establish conditions for a successful attack by the striking force. It typically has most of
  the countermobility assets of the defending unit. The sustainment commander supports tempo by delivering
  mission-essential tailored supplies and materiel as far forward as possible by employing unit distribution to
  deliver preplanned and preconfigured packages of essential items.
  5-218. The striking force typically consists of one-half to two-thirds of the defender’s combat power. It
  decisively engages the enemy as attacking forces become exposed in their attempt to overcome the fixing
  force. The striking force is normally fully tasked organized with all functional and multifunctional support
  and sustainment assets before its actual commitment. The sustainment element should be task organized into
  a forward logistics element resourced with fuel, munitions, medical treatment, medical evacuation, and
  maintenance recovery assets. The forward logistics element is capable and prepared to rapidly replenish the
  striking force prior to commitment, evacuate personnel and systems, and sustain mission-essential
  capabilities throughout the battle. Additionally, sustainment must be prepared to support the transition to a
  spoiling attack with refueling, rearming, casualty evacuation, and battle damage assessment and repair of
  combat capability to extend operational reach.
  SUSTAINMENT SUPPORT DURING MOBILE DEFENSE
  5-219. The sustainment mission of a mobile defense requires sustainment planners look beyond the fixing
  force’s shaping operations to support the striking force’s decisive counterattack. The greater the distance the
  striking force must cover when moving from its assembly area to its final objective, the greater the amount
  of supplies needed to support that move. The mobile defense typically requires more fuel, provides less time
  for maintenance repairs, and requires more complex casualty evacuation procedures due to the dynamic
  nature of this defense.
  5-220. Commanders establish casualty evacuation procedures for both the fixing force and the striking force
  and ensure that all unit personnel are trained in casualty response procedures, tactical combat casualty care
  (self-aid, buddy aid, and combat lifesaver), evacuation of the sick and wounded, and medical aspects of injury
  prevention. The fixing force will likely suffer a higher percentage of casualties than the striking force as it
  absorbs the enemy’s attack. When the striking force must move a considerable distance from its sustaining
  base, the commander should consider establishing a forward logistics element that includes a medical
  capability.
  RETROGRADE
  5-221. Retrograde is a type of defensive operation that involves organized movement away from the enemy
  (ADP 3-90). The enemy may force these operations, or a commander may execute them voluntarily. The
  higher commander of the force executing the retrograde must approve the operation before its initiation in
  either case. Retrograde is a transitional operation; it is not conducted in isolation. It is part of a larger
  maneuver scheme designed to regain the initiative and defeat the enemy.
  SUSTAINMENT PREPARATION FOR RETROGRADE
  5-222. The sustainment provided is mobile enough to cope with demands of the fluid tactical situation that
  typically occurs during a retrograde operation. The sustainment commander prevents unnecessary supplies
  from accumulating in areas that will be abandoned. Only essential medical and logistics support should be
  located in the area involved in the retrograde operation.