TACTICS: Envelopment, Turning Movement & Infiltration

Yesterday we covered two forms of maneuver, both straight-ahead attacks. The Frontal Attack (across a broad enemy front) and the penetration (exploiting a breach in an enemy defense and driving through).

Today we’ll cover three more complex forms: Turning movement, envelopment and infiltration. [Editor's note: Do you remember when you signed up we said we deliver 1-2 minute reads each morning that you can consume with your breakfast? today's gonna require a second cup of coffee].

As always, italics added for our emphasis and commentary, and […] indicates we cut out stuff we thought was fluff. And, as always: you’re smarter reading the doctrine yourself to be exactly sure.

The major takeaways:

Envelopment

• form of maneuver in which an attacking force avoids an enemy’s principal defense by attacking along an assailable flank.

• An envelopment avoids the enemy force’s strength—the enemy’s front—where the effects of enemy fires and obstacles are generally the greatest and attacks the enemy to the flank or rear.

• Envelopments force the enemy to fight in two or more directions simultaneously to meet the converging efforts of an attack.

• Units prefer to conduct an envelopment because generally the flanks of the defending forces are weaker.

• The three variations of the envelopment each have their own structures for organization. Tose variations are—

  • Single envelopment.

  • Double envelopment.

  • Vertical envelopment (AKA airborne or air assault operations)

TURNING MOVEMENT

• A form of maneuver in which the attacking force seeks to avoid the enemy’s principal defensive positions by attacking to the rear of their current positions forcing them to move or divert forces to meet the threat.

• A turning movement differs from an envelopment because the force conducting a turning movement seeks to make enemy forces displace from their current locations, whereas an enveloping force seeks to engage enemy forces in their current locations from an unexpected direction.

• It can also be conducted using waterborne or amphibious means.

INFILTRATION

• A form of maneuver in which an attacking force conducts undetected movement through or into an area occupied by enemy forces.

• Infiltration is also a march technique used well before encountering enemy forces to avoid enemy information collection assets.

• Infiltration occurs by land, water, air, or a combination of means.

• A successful infiltration requires the infiltrating force to avoid detection and engagement by enemy forces.

• Infiltrated forces alone can rarely defeat an enemy force [because of size/capability limitations], units use infiltration in conjunction with and in support of other forms of offensive maneuver.

• Purposes:

  • Reconnoiter known or templated enemy positions and conduct surveillance […]

  • Attack enemy-held positions from an unexpected direction.

  • Occupy a support by fire position to support the main effort.

  • Secure key terrain.

  • Conduct ambushes and raids to destroy vital facilities […]

  • Conduct a covert breach of an obstacle or obstacle complex.

• Special operations forces and dismounted infantry units up to brigade size are best suited to conduct an infiltration.

Diving deep in the doctrinal details:

ENVELOPMENT

2-58. Envelopment is a form of maneuver in which an attacking force avoids an enemy’s principal defense by attacking along an assailable flank. An envelopment avoids the enemy force’s strength—the enemy’s front—where the effects of enemy fires and obstacles are generally the greatest and attacks the enemy to the flank or rear. Envelopments force the enemy to fight in two or more directions simultaneously to meet the converging efforts of an attack. Envelopments focus either on seizing terrain, destroying enemy forces, or interdicting enemy withdrawal routes. Units prefer to conduct an envelopment instead of a penetration or a frontal attack because generally the flanks of the defending forces are weaker and provide the attacking forces the most opportunities to destroy the enemy force. The main effort focuses on attacking an assailable flank. If no assailable flank is available, the attacking force creates one through the conduct of a penetration. The three variations of the envelopment are—

• Single envelopment.

• Double envelopment.

• Vertical envelopment.

2-59. A single envelopment is a variation of envelopment where a force attacks along one flank of an enemy force. A single envelopment is generally easier to control and does not require a significant number of forces. See figure 2-16 on page 2-20 for an illustration of a single envelopment.

2-60. A double envelopment is a variation of envelopment where forces simultaneously attack along both flanks of an enemy force. A force seeking to execute a double envelopment must also have a substantial mobility advantage over defending forces. A unit performs a double envelopment by conducting a frontal attack to fix enemy forces in place while enveloping both of the enemy force’s flanks. A double envelopment generally requires more forces than a single envelopment and are more difficult to control.

2-61. A vertical envelopment is a variation of envelopment where air-dropped or airlanded troops attack an enemy forces’ rear, flank, or both. A force seeking to execute a vertical envelopment requires the necessary vertical lift capability and indirect fire assets to suppress enemy air defense capability. Because of the forces required, normally only divisions and larger organizations can conduct double and vertical envelopments, since these organizations have the resources and the capability to control these envelopments. A vertical envelopment, by either airborne assault or air assault, allows the commander to—

• Overcome distances quickly, overfly barriers, and bypass enemy defenses.

• Extend the area over which the commander can exert influence.

• Leaves the enemy defenses more vulnerable to attack from the main body.

• Disperse reserve forces widely for survivability reasons while maintaining their capability for effective and rapid response.

• Exploit combat power by increasing tactical mobility.

• Seize key terrain to deny the enemy’s use

TURNING MOVEMENT

2-71. A turning movement is a form of maneuver in which the attacking force seeks to avoid the enemy’s principal defensive positions by attacking to the rear of their current positions forcing them to move or divert forces to meet the threat. A turning movement differs from an envelopment because the force

conducting a turning movement seeks to make enemy forces displace from their current locations, whereas an enveloping force seeks to engage enemy forces in their current locations from an unexpected direction. It can also be conducted using waterborne or amphibious means. Figure 2-18 graphically depicts a turning movement. Units frequently transition this form of offensive maneuver from the attack into an exploitation or pursuit. The turning force must also be capable of operating outside supporting distances for a set time. Only divisions and above can execute a turning movement. This is due to these echelons possessing the organic resources to organize a turning force that can operate outside the supporting distance of the main body and force enemy units out of their current positions. execute a turning movement.

Organization of Forces

2-72. The task organization for a turning movement are the following:

• Security force.

• Diversion force.

• Turning force.

• Reserve.

2-73. The security force performs security and reconnaissance tasks as part of its enabling operations. A diversion force is task-organized to ensure the success of the turning force. The diversion force conducts operations, such as attacks designed to divert the enemy force’s attention away from the turning force. The force conducting the turning movement is the turning force. The turning force conducts the echelon’s main effort and is resourced appropriately. The reserve is positioned to support the turning force. However, the reserve can support the security or diversion force if required.

Control Measures

2-74. Units designate control measures as necessary to synchronize subordinate force’s operations. These control measures include—

• Phase lines.

• Contact points.

• Objectives.

• Limits of advance.

• Appropriate fire control measures

INFILTRATION

2-82. An infiltration is a form of maneuver in which an attacking force conducts undetected movement through or into an area occupied by enemy forces. Infiltration is also a march technique used well before

encountering enemy forces to avoid enemy information collection assets. Infiltration occurs by land, water, air, or a combination of means. Moving and assembling forces covertly through enemy positions takes a lot of time. A successful infiltration requires the infiltrating force to avoid detection and engagement by enemy forces. Since this requirement limits the size and strength of the infiltrating force, and infiltrated forces alone can rarely defeat an enemy force, units use infiltration in conjunction with and in support of other forms of offensive maneuver. Figure 2-19 depicts an infiltration.

2-83. Units conduct infiltration to move all or a portion of a unit through gaps in the enemy force’s defenses to—

• Reconnoiter known or templated enemy positions and conduct surveillance of named areas of interest and targeted areas of interest.

• Attack enemy-held positions from an unexpected direction.

• Occupy a support by fire position to support the main effort.

• Secure key terrain.

• Conduct ambushes and raids to destroy vital facilities and disrupt the enemy force’s defensive structure by attacking enemy reserves, fire support and air defense systems, communications nodes, and sustainment elements.

• Conduct a covert breach of an obstacle or obstacle complex.

2-84. Special operations forces and dismounted infantry units up to brigade size are best suited to conduct an infiltration. In some circumstances, armored- and Stryker-equipped forces operating in small units can conduct an infiltration when the terrain can mask their force’s movement signature. The proliferation of technology leads to increased situational understanding for both friendly and enemy forces as well as an increased chance of detecting units conducting an infiltration. Understanding the capabilities of these technologies informs the decision as to whether an infiltration is feasible.

Do you have an assailable flank because of gaps in your doctrinal knowledge? Reinforce with A Doctrine Deep Dive with a read of FM 3-90 here.