text: Appendix C
  Encirclements
  Encirclements are an outcome that can result from offensive operations to isolate and
  destroy enemy forces or result from a friendly force being isolated by enemy forces.
  This appendix provides an overview of encirclement operations and consists of the
  organization of forces for an encirclement, control measures, and planning and
  execution of encirclement operations. It also includes what to do if a unit is encircled
  and how to break out from an encirclement.
  ENCIRCLEMENT OVERVIEW
  C-1. Encirclement is where one force loses its freedom of maneuver because an opposing force is able
  to isolate it by controlling all ground lines of communications and reinforcement. A unit can conduct
  offensive encirclement operations designed to isolate an enemy force or they could become encircled
  resulting from the unit's isolation by the actions of an enemy force. Encirclements occur because combat
  operations involving modernized forces are likely to be chaotic, intense, and highly destructive, extending
  across large areas containing relatively few units as each side maneuvers against the other to obtain positional
  advantage.
  C-2. Typically, encirclements result from penetrations and envelopments, or are extensions of exploitation
  and pursuit operations that bypass large enemy forces in order to maintain momentum. As such, they are not
  a separate form of maneuver but an extension of an ongoing operation. They may be planned sequels or result
  from exploiting an unforeseen opportunity. They usually result from the linkup of two encircling arms
  conducting a double envelopment. However, they can occur in situations where an attacking unit uses a major
  obstacle, such as a shoreline, as a second encircling force. Although a commander may designate terrain
  objectives in an encirclement, isolating and destroying or defeating enemy forces are the focus. Ideally, an
  encirclement results in the surrender of the encircled force. This minimizes friendly force losses and resource
  expenditures. A key consideration prior to executing an encirclement is understanding that the encircling
  force is fixed and therefore unavailable for other operations until the enemy force being encircled is reduced.
  ORGANIZATION OF FORCES FOR AN ENCIRCLEMENT
  C-3. An encirclement operation usually has at least two phases—the actual encirclement and actions taken
  against the isolated enemy forces. Commanders consider adjusting subordinate units’ task organizations
  between phases to maximize unit effectiveness in each phase. The first phase is the actual encirclement that
  results in the enemy force’s isolation. The organization of forces for an encirclement is similar to that of a
  movement to contact or an envelopment. The unit executing an encirclement organizes encircling forces into
  a direct pressure force and one or more encircling arms. Armored, mechanized, and motorized infantry, air
  assault, and airborne units are especially well suited for use as an encircling force since they have the tactical
  mobility to reach positions that cut enemy ground lines of communication. Bypassed and non-encircled
  enemy forces on the flanks and rear of advancing friendly forces require all around security.
  C-4. A commander should direct the encirclement effort. However, there must also be unity of command
  for each encircling arm. The encircling force headquarters may name one of its subordinate units as the
  headquarters for an encircling arm. Alternatively, that force’s headquarters may create a temporary command
  post from organic assets, such as its tactical command post, to control one or more arms of the encirclement.
  If that encircling arm has subordinate inner and outer arms, each of them also requires separate subordinate
  commanders. The missions and spatial orientation between the inner and outer encircling arms are
  sufficiently different; therefore, one force cannot act in both directions at once. Figure C-1 on page C-2
  depicts an encirclement.