text: Chapter 6
  6-100. Encirclement operationsare operations where one force loses its freedom of maneuver because an
  opposing force is able to isolate it by controlling all ground lines of communication and reinforcement
  (ADP3-90). An encirclement operation usually has at least two phases-the actual encirclement and the action
  taken against the isolated enemy. The commander considers adjusting subordinate units’task organizations
  between phases to maximize unit effectiveness in each phase. The first phase is the actual encirclement that
  isolates the enemy force. The organization of forces for an encirclement is similar to that of a movement to
  contact or an envelopment. The commander executing an encirclement operation organizes encircling forces
  into a direct pressure force and one or more encircling arms. (See figure 6-4.)
  6-101. The commander organizes an inner encircling arm only if there is no possibility of the encircled
  forces receiving relief from enemy forces outside the encirclement. The commander organizes both inner and
  outer encircling arms if there is any danger of an enemy relief force reaching the encircled enemy force. The
  commander assigns the outer encircling arm a security mission, an offensive mission to drive away any
  enemy relief force, or a defensive mission to prevent the enemy relief force from making contact with the
  encircled enemy force. Once the encirclement is complete, these inner or outer encircling arms form a
  perimeter. (See FM 3-90-2 for additional information.)
  Figure 6-4. Encirclement operations
  TURNING MOVEMENT
  6-102. Aturning movementis a form of maneuver in which the attacking force seeks to avoid the enemy’s
  principle defensive positions by seizing objectives behind the enemy’s current positions thereby causing the
  enemy force to move out of their current positions or divert major forces to meet the threat (FM 3-90-1). A