text: Fire Support in Depth During Large-Scale Combat Operations
  enemy from gaining a position of advantage. Countermobility operations are conducted to support forces that
  are operating along the range of military operations. Countermobility operations directly support offensive
  and defensive operations. For more information on countermobility operations see ATP 3-90.8.
  6-149. Commanders must ensure that obstacles are integrated with observation and fires to defeat or disrupt
  enemy attempts to breach friendly obstacles. These fires must be fully synchronized with the concept of
  operations to avoid hindering any friendly-force mobility. Consider the use of scatterable mines to prevent
  repositioning of enemy forces without hindering friendly actions, and to disrupt the enemy counterattack.
  ENCIRCLEMENT
  6-150. Encirclement is no longer an enabling operation but is still a desired outcome. There are special
  planning considerations required to create, maintain, reduce, and when encircled, break out of an
  encirclement. 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. 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 (FM 3-90). 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 see figure 6-7 on page 6-36.
  6-151. Defending forces can become encircled at any time during large-scale combat operations. This is
  especially true during noncontiguous operations. An encircled force can continue to defend encircled,
  conduct a breakout, exfiltrate toward other friendly forces, or attack deeper into enemy-controlled territory.
  A commander's form of maneuver once becoming encircled depends on the senior commander's intent and
  the mission variables METT-TC (I). It is important for the encircled force to continue its mission, establish
  communication with higher HQ, and act on its own initiative within the intent of the higher commander. The
  most likely COA facing the encircled force is to try a breakout toward friendly forces and prepare for linkup
  operations.
  6-152. The following must be considered in a breakout toward friendly troops:
  * Plan fires to support the immediate defense and the breakout.
  * Reorganize available FS assets, and coordinate with FS elements outside the encircled force for
  additional FS.
  * Establish FSCMs.
  * RFAs around encircled forces and RFLs between converging breakout and linkup forces should
  be considered. Airspace coordination areas in the vicinity of the breakout point are necessary if
  CAS is used.
  * Concentrate massed and continuous fires at the breakout point to open a gap for the rupture force.
  * Plan for WLR sectors of search, use CFFZs over known and suspected enemy locations and place
  CFZs over the encircled force.
  * Plan for linkup operations by establishing FSCMs to facilitate FS operations between friendly
  forces.
  * Make use of all lethal and nonlethal capabilities to deceive the enemy as to the location of the
  breakout.
  6-153. Offensive encirclement operations are conducted by corps and division to isolate targeted enemy
  forces. Typically, encirclements result from penetrations and envelopments, or are extensions of exploitation
  and pursuit operations. As such, they are not a separate form of the offense but an extension of an ongoing
  operation. They may be planned sequels or result from exploiting an unforeseen opportunity.
  6-154. Once a decision is made to reduce an encirclement, the commander normally uses one of two
  possible methods of reduction-fire alone or fire and maneuver. Reduction by fire alone implies that the
  encircling friendly commander will use FS as the primary or sole means of reducing the encirclement. This
  includes employing artillery, direct fires, CAS, CEMA, attack helicopters and armed UAS against the enemy
  perimeter. Reduction by fire alone reduces the number of casualties suffered by the friendly encircling force.
  For more information on offensive and defensive encirclement see FM 3-90.