text: Chapter 10
  enemy force. It can obtain this mobility through task organization, countermobility operations to slow and
  disrupt enemy movements, and mobility operations to facilitate the rapid shifting of friendly formations. The
  striking force requires access to multiple routes because an attacking enemy force normally denies the
  defending force freedom of action.
  10-10. Resourcing a reserve in a mobile defense is difficult and requires commanders to analyze risk. The
  unit must balance the size of the reserve with taking forces away from either the fixing or strike force.
  Commanders generally plan priorities for the reserve to prevent the fixing force from failing or to exploit the
  success of the striking force.
  CONTROL MEASURES FOR A MOBILE DEFENSE
  10-11. Since the mobile defense is the combination of a unit conducting an area defense and a separate unit
  conducting a counterattack, it takes control measures from both. These control measures include designating
  assigned areas of the fixing and striking forces with their associated boundaries, BPs, and phase lines. Units
  designate a LD or a line of contact as part of the graphic control measures for the striking force. They may
  designate an axis of advance for the striking force. Units can designate attack by fire or support by fire
  positions. They use engagement areas, TRPs, TAIs, and FPFs as necessary. They designate NAIs to focus
  the efforts of reconnaissance and surveillance assets. This allows units to determine an enemy force’s course
  of action. Units also designate checkpoints, contact points, passage points, passage routes, and passage lanes
  for use by reconnaissance and surveillance assets, security units, and the striking force. Figure 10-3 depicts
  example control measures for a mobile defense.
  Figure 10-3. Example of mobile defense control measures
  10-12. Commanders provide the striking force commander with control measures to focus the striking force
  at the decisive time and place and to deconflict fires with the fixing force. At a minimum, the striking force
  commander needs to know decision points that lead to the commitment of the striking force, the limit of
  advance, and boundaries of the striking force’s assigned area. If the overall commander imposes either an
  axis of attack or a direction of attack as a control measure, that higher echelon commander restricts the