text: Tactical Mission Tasks
  in an approach march before it can deploy into a movement formation. A commander determines the degree
  of acceptable risk based on anticipated friendly losses, the location of the attack, the number of attacks, and
  other risk management factors.
  B-31. Disrupt is an obstacle effect that focuses fire planning
  and obstacle effort to cause the enemy to break up its
  formation and tempo, interrupt its timetable, commit
  breaching assets prematurely, and attack in a piecemeal
  effort. It also helps to deceive an enemy force concerning the
  location of friendly defensive positions, to separate combat
  echelons, or to separate combat forces from their logistics
  support. The short arrows in the obstacle effect graphic indicate
  where obstacles impact the enemy’s ability to maneuver. The
  longer arrows indicate where units allow enemy forces to
  Figure B-14. Disrupt obstacle
  bypass the obstacle effect, so the defending force can engage
  effect
  the enemy force with fires. The arrows indicate the direction of
  an enemy attack. A defending unit normally uses the disrupt obstacle effect forward of engagement areas.
  Obstacles alone cannot disrupt an enemy unit. Figure B-14 depicts the disrupt obstacle effect. (See Chapter
  17 for more information on the disrupt obstacle effect.)
  EXFILTRATE
  B-32. Exfiltrate is a tactical mission task in which a unit removes
  Soldiers or units from areas under enemy control by stealth,
  deception, surprise, or clandestine means. Friendly forces use stealth,
  deception, surprise, or other clandestine means to exfiltrate the area.
  Friendly forces exfiltrate when they have been encircled by enemy
  forces and cannot conduct a breakout or be relieved by other friendly
  forces. Forces returning from a raid, an infiltration, or a patrol behind
  enemy lines can also conduct an exfiltration. A commander exfiltrates
  an encircled force to preserve a portion of the force; it is preferable to
  the capture of the entire force. A force exfiltrates only after destroying
  Figure B-15. Exfiltrate task
  or incapacitating all equipment, except medical, that it must leave
  behind. Only as a last resort, when the alternative is the capture of the entire force, does a force conducting
  an exfiltration leave its casualties in place with supplies, chaplain support, and medical personnel.
  Figure B-15 depicts the exfiltrate tactical mission task.
  B-33. Exfiltration is most feasible through rough or difficult terrain in areas lightly covered by enemy
  observation and fire. These conditions often allow undetected movement of small elements when movement
  of the entire force would present more risk. Exfiltration requires resourcefulness, a high degree of discipline,
  expert land navigation skills, and motivation. It is unlikely that the entire force will be able to exfiltrate since
  part of it may have to create a diversion. Good, small-unit leadership is essential in this type of operation.
  B-34. The exfiltrating force first establishes its rally points and exfiltration lanes. It coordinates its linkup
  plans with other friendly units. A commander designates exfiltration lanes as RFAs or no-fire areas. The
  exfiltrating force uses preparation fires to cover its movement and to expend stockpiled ammunition. Based
  on reconnaissance and available intelligence, the exfiltrating force subdivides into small groups and
  exfiltrates during periods of limited visibility, passing through or around enemy defensive positions. If
  detected, it tries to bypass enemy forces. Exfiltration may be more difficult with combat and tactical vehicles
  because the noise they make and the limitations they impose on exfiltration routes make detection more
  likely.