Envelopment

Envelopment Is a form of maneuver in which an attacking force seeks to avoid the principal enemy defenses by seizing objectives behind those defenses that allow the targeted enemy force to be destroyed in their current positions. At the tactical level, envelopments focus on seizing terrain, destroying specific enemy forces, and interdicting enemy withdrawal routes. The commander’s decisive operation focuses on attacking an assailable flank. It avoids the enemy’s strength—the enemy’s front— where the effects of enemy fires and obstacles are the greatest. Generally, a commander prefers to conduct envelopment instead of a penetration or a frontal attack because the attacking force tends to suffer fewer casualties while having the most opportunities to destroy the enemy. Envelopment also produces great psychological shock to the enemy. If no assailable flank is available, the attacking force creates one through the conduct of a penetration. The four varieties of envelopment are the single envelopment, double envelopment, encirclement, and vertical envelopment. (See figure 1-1 and 1-2) A single envelopment results from maneuvering around one assailable flank of a designated enemy force. A double envelopment results from simultaneous maneuvering around both flanks of a designated enemy force. Encirclement operations are 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. Vertical envelopments are tactical maneuvers in which troops, either air-dropped or airlanded, attack the rear and flanks of a force, in effect cutting off or encircling the force. (JP 3-18). (For a discussion of encirclement operations, see FM 3-90-2.)

• Single and Double Envelopments* Forces the enemy to fight in two or more directions simultaneously to meet the converging efforts of the attack. A double envelopment generally requires a preponderance of force and can be difficult to control. A force seeking to execute a double envelopment must also have a substantial mobility advantage over the defender. A unit performs a double envelopment by conducting a frontal attack as a shaping operation in the center to fix the enemy in place while enveloping both hostile flanks. Because of the forces required, normally only divisions and larger organizations have the resources to execute a double envelopment.

===Organization of Forces=== The commander envisioning a single envelopment organizes the friendly force to perform two primary tasks: fixing the enemy force in its current location and conducting the envelopment. The commander also allocates forces to conduct necessary shaping operations, such as reconnaissance, security, reserve, and sustaining tasks. The force conducting the envelopment normally conducts the decisive operation by attacking an assailable enemy flank and avoiding the enemy’s main strength en route to the objective. The fixing force conducting the shaping operations normally conducts a frontal attack to fix enemy forces in their current positions to prevent their escape and reduce their capability to react against the enveloping force. A commander executing a double envelopment organizes the friendly forces to conduct two enveloping operations and allocates the minimum combat power to shaping operations required to conduct the fix tasks in addition to reconnaissance, security, reserve, and sustaining tasks. The commander typically designates the more important of the two enveloping forces as the main effort for resources. The main effort is a designated subordinate unit whose mission at a given point in time is most critical to overall mission success (ADRP 3-0) ====Control Measures==== The commander, at a minimum, designates AOs for each unit participating in the envelopment by using boundaries. The commander also designates phase lines (PLs), support by fire and attack by fire positions, contact points, and appropriate fire coordination measures, such as a restrictive fire line or boundary between converging forces, and any other control measures necessary to control the envelopment. Figure 1-3 is an example of control measures used when conducting a single envelopment. =====Planning an Envelopment===== Successful envelopment planning depends on knowing and understanding the enemy and its capabilities. The commander seeks to maneuver the enveloping force around or over the enemy’s main defenses to secure objectives on the enemy’s flank or rear. From those objectives the enveloping force can use its positional advantage to employ superior combat power against a defending enemy oriented in the wrong direction. The commander uses intelligence assets and personnel to determine the disposition and capabilities of enemy forces to detect and react to their operations. The commander plans for the force conducting the envelopment to remain within supporting distance of the fixing force. (If the enveloping force is going outside of supporting distance, it is probably conducting a turning movement, not envelopment.). Sustaining the enveloping force requires deliberate planning because only intermittent ground lines of communication (LOCs) between the echelon support area and the enveloping force may exist. A line of communications is a route, either land, water, and/or air, that connects an operating military force with a base of operations and along which supplies and military forces move (JP 2-01.3). The commander plans how to exploit the envelopment’s success as the enemy is encircled or how to transition to a pursuit to complete the destruction of the enemy force. These plans are developed as branches and sequels to the envelopment operation. ======Executing an Envelopment====== A successful envelopment depends largely on the degree of surprise the commander achieves against the opponent or the presence of overwhelming combat power. The envelopment’s probability of success also increases when the commander’s forces have superior tactical mobility, possess air and information superiority, and shaping operations fix the bulk of the enemy’s forces in their current positions. The commander uses reconnaissance and surveillance assets to provide continuous intelligence and combat information to identify changes in enemy COAs throughout the execution of the envelopment. Normally, a unit orients the majority of its combat power toward where it expects to engage enemy forces, while placing less combat power on its own flanks. Thus the flanks of most units are more vulnerable to attack. The attacking commander creates an assailable flank using whatever means necessary. The enveloping force then moves rapidly to exploit the situation before the enemy strengthens an assailable flank by preparing positions in depth and by holding mobile forces in reserve. When faced with the threat of envelopment, the enemy commander might move reserves to meet the enveloping force. Thus, rapid movement around the enemy’s flank is essential to prevent the enemy from occupying previously prepared positions. Ground and air assets conducting vigorous shaping operations attempt to prevent the enemy commander from reconstituting reserves from other portions of the enemy front. The enemy may attempt to cut off the enveloping force and extend its flank beyond the area that the enveloping force is attempting to attack through. If the encircling force attempts to outflank such a hostile extension, it may become overextended by moving outside of supporting distance from the fixing force. Therefore, it is usually better for the encircling force to take advantage of the enemy’s extension and subsequent weakness by penetrating a thinly held area of the enemy’s front rather than overextending itself in an attempt to completely outflank the enemy’s position. The enemy may attempt a frontal counterattack in response to an attempted envelopment. In this case, the fixing force defends itself or conducts a delay while the enveloping force continues the envelopment. After the initial envelopment of one flank—which places the enemy at a disadvantage—the commander has many options. The commander may choose to establish favorable conditions for passing to a double envelopment by using reserves, or the commander may exploit success by generating additional combat power along the same axis. Alternatively, the commander can destroy or defeat the enveloped enemy force in place, or transition to another type of operation, such as an exploitation or pursuit

References

ADRP 3-90, Offense and Defense, August 2012 FM 3-90-1, Offense and Defense Vol. 1, March 2013 FM 3-90-2, Reconnaissance, Security, and Tactical Enabling Tasks Vol. 2, March 2013