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Chapter 4


Joint task forces, corps, divisions, and brigades use a variety of tactics and techniques to execute a defense. The tactics and techniques in this chapter describe only one way the AASLT division may conduct operations.


The defense is a temporary measure adopted until the division can resume or assume the offense. Defense as a form of warfare does not directly produce decisive victory. Therefore, the division aggressively conducts the defense to wrest the initiative from the attacker.

The commander mixes defensive and offensive tasks in his defensive concept of operations. His concept clearly identifies how to seize the initiative. His concept also envisions a sequel to maintain the initiative, transition to the offense, and exploit tactical successes.

The defense may be one battle or a series executed over time. The division gives subordinate units defensive tasks to contain or trap an enemy force, deny area access, attrit the enemy, or perform tasks with an economy of force characteristic.

The division also gives some units tasks to attack or counterattack. The intent is to set the conditions to gain (or regain) and maintain the initiative for decisive offensive action. Without a compelling reason to defend, the division attacks.

There are two forms of defense--mobile and area. Mobile defense orients on the destruction of enemy forces by trading terrain to expose the enemy to a counterattacking mobile striking force. Area defense focuses on denying the enemy access to designated terrain for a specified time, rather than the outright destruction of the enemy.

Mobile defense can be more lethal than area defense because it concentrates the bulk of combat power on the enemy force, producing a decisive result. It requires a large mobile striking force, the capability to mass overwhelming fires, adequate maneuver area in depth, and at least air parity with an effective air defense. The mobile defender has the freedom and capability to maneuver.

Area defense forces deploy laterally and in depth, retaining terrain rather than focusing on enemy destruction. When defending against armored forces in close terrain, area defenses normally defend on high-speed avenues of approach. Area defenses are best--

  • In rough terrain.
  • When a unit must retain specific terrain.
  • When the sector lacks depth.
  • When the defender lacks sufficient maneuver potential compared to the enemy.
  • When operating independently, as in a jungle or when encircled, units may find themselves in a perimeter defense.


    All defenses must use terrain properly. Terrain is a force multiplier for infantry units. It facilitates massing combat power at the decisive point of the battle by allowing smaller forces to defend restrictive terrain elsewhere.

    Terrain, reinforced by barriers, influences enemy movements and tempo for exploitation. It degrades enemy maneuver and can fix him for effective attack in a location decided by the defending force commander. Terrain also provides cover and concealment.

    All defenses conduct security operations. The defender has the advantage of terrain, but initially lacks the initiative.

    Defenders accept risk in some areas in order to mass combat power elsewhere by assigning to units missions that have economy of force characteristics. Security operations prevent surprise and reduce the risk of bypass or encirclement of the main effort.

    Defense in depth provides flexibility and dispersion while reducing risk. Deployment in depth provides time to assess and react to changes on the battlefield once the battle begins. Defense in depth facilitates--

  • Shifting of forces.
  • Counterattacks.
  • Using EAs, barriers, and improved positions to canalize, delay, or attrit in depth.
  • Attacking the enemy's flanks and rear.
  • Deception planning.
  • Mutual support integrates the fires of the total force. It allows a dispersed force but focuses combat power.

    The AASLT division is a tactically mobile force with respect to terrain. After AASLT insertion, it lacks maneuver speed potential unless it fights an enemy with equal or less maneuver capability.

    The division can defend successfully in close terrain against mechanized or motorized forces when properly augmented with antiarmor or mechanized forces. The division may be part of a corps defense to act as an anchor, allowing other divisions to concentrate for a counterattack or envelopment.

    As a pure AASLT division, the division can conduct an area defense in appropriate terrain to block dismounted enemy movements. It can also defend against an enemy infantry armored force which has small organic tank units.

    An armored brigade in support of a light division constitutes a light-armored operation. (See also Chapter 7.) Of the light divisions, only the AASLT division conducts mobile defense operations without augmentation.

    Normally, the best technique for halting an enemy armored attack is to use a combination of artillery, attack helicopters, USAF aircraft, integrated obstacle plans, and the division's medium and heavy antitank (AT) systems.


    In most cases, the AASLT division defends by conducting cross-FLOT offensive operations to spoil enemy attacks or to counterattack the depth of threatening penetrations. In some cases, the division executes missions in the corps covering force area (CFA) or main battle area (MBA) in accordance with the defensive framework. In such circumstances, careful METT-T evaluation by the division commander and his staff develops a basis on which to allocate forces to each of the five portions of the defensive framework. Even in the corps CFA or MBA, the division organizes to infuse its defense with a strong offensive posture, maximizing opportunities for raids and air assaults.

    The aviation brigade conducts most deep operations, which may include infantry teams or TFs for combined-arms (CA) raids. The aviation brigade conducts raids to identify, slow, disrupt, and/or delay enemy forces entering the division sector.

    DIVARTY fires conduct SEAD, as necessary, in support of deep operations missions. The division coordinates with the corps to conduct most deep operations missions in the event the aviation brigade forms the division's covering force or if the division as a whole assumes the corps' covering force role.

    Security operations prevent surprise and allow time for further defensive preparations in the MBA. They extend to the main body's front, flanks, and rear.

    If the division creates a covering force, either the aviation brigade or a maneuver brigade fills this role. The air cavalry squadron often screens along a critical avenue of approach or exposed flank. When used, the division's cover force exists to slow the enemy advance, force premature deployment, clearly locate the foe's main thrust, and destroy his artillery and air defenses to desynchronize his attack.

    In the MBA, maneuver brigades defend in sector to defeat the opposition's attack, destroy his forces, and create conditions for a decisive counterattack. Depending on allocation of forces for other tasks, two brigades generally fight in the MBA, with one as the main effort. An OPCON armored contingent could contribute greatly to this part of the battlefield. Although assault and attack aviation units fight in the MBA, the aviation brigade rarely controls the action in any part of this area.

    Rear operations demand forces in the defense based on a METT-T analysis. The division cannot discount the dangers of the enemy conducting deep operations for raiding and securing key terrain. Immediate, violent counterattacks address these threats as soon as they appear.

    With the need for rapid response in mind, the division allocates an assault aviation unit to the rear operations TF, likely from the command aviation battalion. Doing so ensures the division has immediate access to artillery and attack aviation in a defined command or support relationship.

    The division retains up to one brigade in reserve. The reserve brigade reinforces the MBA effort or air assaults to secure key terrain, thereby blocking the withdrawal of defeated enemy forces or the introduction of reinforcements.

    If the defensive sector is large, the enemy strong, and much of the division is holding key terrain, the division might designate as little as an understrength battalion TF as a formal reserve. This reflects the understanding that, as in all AASLT operations, every uncommitted force represents a potential reserve.

    Unlike the offense, the defensive framework alters significantly, based principally on the mission--to counterattack as the corps reserve, to fight in the CFA, or to fight in the MBA. No "generic" defensive framework characterizes the AASLT division in the defense.

    In an ideal defense, the AASLT division seeks and exploits every opportunity for offensive action. As much as possible, the division plans and executes raids and air assaults in the rear of advancing hostile formations, thereby dividing the enemy's attention and degrading the integration of his combat power. The AASLT division continues to look, think, and fight deep as much as possible during all operations unless higher headquarters directs otherwise.


    Terrain Retention

    In the following example, the corps defends with one AASLT division and one armored division abreast and an armored cavalry regiment (ACR) covering force. It has a separate mechanized brigade in reserve. The corps defends against part of an enemy corps.

    The enemy corps is a secondary effort. It will probably attack in the friendly corps sector with four infantry divisions, one mechanized infantry brigade, and one armored regiment.

    Terrain in the corps sector is restrictive, with narrow valleys and many small built-up areas. Terrain restricts vehicle traffic mostly to improved roads and a few wide areas in valleys.

    The terrain generally allows more maneuver in the armored division's defensive sector. The infantry division's defensive sector is in the northern half of the corps sector (Figure 4-1).

    The AASLT division defends in sector in an area dominated by high rugged hills and a small built-up area. One improved highway runs the length of the sector.

    The corps commander intends to anchor his defense with infantry on his left defending in restrictive terrain. The corps armored division defends in depth on the right.

    The ACR is the corps covering force. The corps reserve (a separate armored brigade) positions itself behind the armored division.

    The ACR moves to a corps assembly area after the covering force fight. The corps commander wants to defeat the enemy's attack forward of PL DOG. The separate mechanized brigade will then counterattack to destroy remaining enemy formations in zone and to restore the FEBA. Corps deep operations initially focus on distant, uncommitted enemy forces, targeting any mechanized or armored units moving forward to exploit penetrations.

    Since defense in sector tends to be stationary, it is vulnerable. Deception and OPSEC are critical in preventing the enemy from accurately templating friendly defensive positions and intentions. Using dummy positions and manning alternate or supplementary positions will be necessary to confuse enemy targeting.

    Defending forces require security, counterreconnaissance, and smoke operations to deny enemy direct observation. As time permits, units take additional measures to protect themselves and increase their weapons effectiveness.

    A stationary defense does not directly challenge the enemy's initiative until decisive combat begins.

    Normally it occurs only when the likelihood exists of achieving a compelling advantage over the enemy.


    The AASLT division defends in sector with three brigades on line along PL DOG (Figure 4-2). The division commander retains one infantry battalion as division reserve.

    The main effort is in the south where potential for an enemy mechanized force exploitation exists. The enemy will probably try to infiltrate around the built-up areas. He will also probably conduct a supporting attack in the north.

    Figure 4-3 depicts the division's task organization. This division is the corps' supporting effort; therefore, its share of corps supporting units is small.

    Deep Operations. The division must initially find and target enemy artillery units--the greatest threat to AASLT units' freedom of maneuver. Target type defines the proactive counterfire operation as a deep operation, not distance from the FLOT or relative location with respect to a phase line.

    Deep operations can alter the combat power ratio for current and subsequent close operations. They destroy artillery, attrit infantry formations, and disrupt the enemy's attempt to mass, attacking enemy division echelons in depth as they approach the FEBA.

    Brigades engage leading enemy regiments in the division's close fight. Follow-on enemy regiments and reserves are division deep targets. The corps attacks other enemy divisions as the enemy moves forward.

    The corps and the division enter an agreement to define close and deep operations areas to delineate deep operations responsibilities for ground maneuver targets. Phase lines create points where the corps and division accomplish handover coordination for responsibilities to attack approaching enemy echelons. Phase lines do not create separate areas where the corps or division conduct uncoordinated concepts of operations. The corps and division coordinate the maneuver concept of operations, intent, and the desired results of deep operations to ensure mutual support.

    The senior commander specifies his intent for deep operations in the OPORD. The senior commander identifies minimum conditions which must be met before air assault operations. The subordinate commander supports this intent and coordinates his concept, intent, and desired effects with the senior commander in the backbrief or rehearsal. Coordination of deep-operations handover and synchronization of intent are especially important for intelligence collection and targeting.

    The division commander reserves proactive counterfire for the deep operation. He identifies enemy artillery units as a specified target type. DIVARTY targets and attacks enemy artillery units anywhere on the battlefield, regardless of the specified phase line for moving enemy infantry or armored units.

    The primary division deep weapons systems are tube artillery, fixed-wing air interdiction (AI), attack helicopters, and MLRS (if available). These are division assets or corps-provided support.

    Close Operations. The AASLT division conducts close defensive operations with mutually supporting positions and integrated obstacles constructed in depth. Defensive operations must keep enemy infantry formations and movements in place. The division can then engage and destroy them with a combination of massed artillery, mortar, attack helicopters, USAF aircraft, and/or AT weapons.

    Attack helicopters and CAS counter enemy armored forces, especially when massed formations deploy to exploit success. Enemy tanks principally act as infantry fire support because of limited maneuver space.

    Brigades position tube-launched, optically tracked, wire-guided (TOW) missiles and DRAGON weapons systems to destroy tanks supporting infantry attacks. Because the enemy commits tank and mechanized units to exploit penetrations, the defending force plans antiarmor fires in depth.

    Area defense, focused on terrain retention, relies on using terrain, obstacles, and massed fires to stop and destroy an attacking enemy. Fires in depth disrupt the enemy's attack plan, but the defender achieves success by overwhelming massed fires at the FLOT.

    If, because of the terrain, the AASLT division cannot use its helicopters to move faster than can the attacking enemy, initial defense at the FLOT is crucial. Thorough reconnaissance to situate the defense is critical.

    The division, brigades, and battalions must reposition units to alternate or supplementary positions before the enemy's main body arrives or before preparation fires. Deep-intelligence operations results trigger repositioning of forces. A decision support template (DST) assists the decision-making process.

    The corps and division consider this type of defense high risk since it orients on retaining terrain. The corps and division can only minimize risk by ensuring the maximum possible depth for defense in front of retained terrain.

    All friendly units must mass fires in coordination with the proper positioning of obstacles to create engagement areas which will hinder the enemy's momentum and initiative. Effective obstacle emplacement causes the enemy to mass, thereby increasing the effectiveness of fires.

    Rear Operations. The division reconnaissance squadron initially screens forward of the LC behind PL WATCH. On withdrawal, it screens behind committed brigades to locate infiltrating and penetrating enemy units. On order, it defends to block or contain the enemy and directs the attack by fires to destroy enemy forces.

    Division CS and CSS units locate in mutually supporting base clusters. Each must establish credible defenses against infiltrating enemy infantry units. Support units locate away from routes suitable for enemy mechanized or armored exploitation. Combat service support elements the division cannot adequately protect locate in the corps rear area.

    Security Operations. The corps ACR conducts covering force operations forward of PL WATCH until withdrawn. Initially, the division reconnaissance squadron screens forward of the main effort behind PL WATCH. The division tasks the northern brigade to screen forward along PL WATCH.

    The mission is to screen because the AASLT division cannot deploy a suitable covering force. This screening force lacks sufficient size, strength, and ground maneuver capability to prevent its being decisively engaged or bypassed by large infantry forces. Therefore, it establishes a screen first for early warning and second for attrition. Units plan for artillery fires and CAS to attrit, disrupt tempo, and support the covering forces' retrograde operation.

    The northern brigade defends in rough terrain where dismounted movement is the norm. The division directs the brigade to conduct its own screen.

    The division reconnaissance squadron conducts its screen in the center and south where the terrain, though rough, allows more movement by large units and vehicles. The screen mission includes counterreconnaissance to detect and destroy enemy reconnaissance units within the squadron's capabilities.

    The division cavalry squadron concentrates its effort forward of the division's main effort--the 3d Brigade. This sector has the most favorable enemy avenues of approach in the division sector. If employed against the division, the enemy armored attack will probably occur in the 3d Brigade area when it attempts to bypass the city to the north.

    The battle handover line (BHL) for the screening force is PL CLOSE. The defending brigades send security elements as far out as PL CLOSE. They mark routes and provide fire support for the retrograde. The BHL partially defines the division's forward security area.

    The enemy will probably attempt infiltrations in support of every attack to bypass or penetrate the main defenses and to attack friendly reserves, C2, and CSS elements. Friendly security operations include combinations of OPs, patrols, and surveillance systems. Maneuver brigades secure the division flanks in sector.

    After withdrawing from the screening mission, the division cavalry squadron moves to the division rear and conducts a screen behind the brigades. The mission is to discover, contain or block, and destroy enemy infiltrations or penetrations into the division rear area.

    In this scenario, the enemy infiltrates and bypasses resistance in every attack. The division must conduct reconnaissance and security operations in the division rear area.

    If the division gives control of the cavalry squadron to the aviation brigade, it should also give them the mission to screen behind the defending brigades. The division's intent is to employ attack helicopters in support of the brigades and the deep operation.

    Reserve Operations. It is difficult for the AASLT division to maintain a large reserve in this mission. The division reserve receives an assault helicopter battalion for dedicated movement capability to react in a timely manner. The division also has one infantry battalion in reserve as well as dedicated lift assets.

    The division carefully plans movement of reserves because of its vulnerability to indirect fires and air attack while moving. Selected reinforcement routes provide cover and concealment while rear area R& S operations decrease the probability of enemy stay-behind or special forces observing reserve locations. Electronic warfare, or fires directed at enemy C2 or fire control headquarters, might degrade the enemy's ability to attack the reserve. Finally, reserve deployment and employment might require artillery and smoke fires.


    Military intelligence assets are task-organized into three company teams, one in direct support to each AASLT brigade. Each company team includes SIGINT, HUMINT, and GSR or REMBASS sensor assets. METT-T factors determine the final mix.

    In the following example, one platoon-size team supports the secondary-effort brigade's company team; the company (-) supports the division's main-effort brigade's company team. One GSR squad is attached to each brigade.

    The fourth GSR squad is attached to the cavalry squadron. It initially supports the cavalry screening force, then the rear area screen. The GSRs orient on supporting brigade operations by detecting enemy infantry infiltrations.

    The LRSD is deployed to observe NAIs, TAIs, or DPs for targeting purposes, Based on the G3's guidance, the division G2 plans and prepares intelligence-collection tasks and guidance.

    The G3 deploys LRSTs with the cavalry screening force. The teams also infiltrate to assigned dispersal areas and select positions that provide long-range observation of assigned areas. The remainder of the I& S company locates at the division EPW collection point.

    The division G2 coordinates intelligence handoff for enemy units from corps to division and division to brigade. The collection plan establishes priorities for friendly units to observe and monitor enemy units, NAIs, and TAIs.

    The division G2 at the TAC CP tracks enemy units into brigade AOs for targeting and situation development. In this example, in order of priority, priority intelligence collection requirements are--

  • Locations and movements of enemy artillery units.
  • Locations and movements of follow-on divisions.
  • Locations and movements of enemy armored or mechanized forces.
  • Locations of enemy division-level C2 facilities.
  • Fire Support

    The organization of artillery, EW, and TACAIR support enhances each's capability to provide massed fire support to defeat enemy attacks in both the main and supporting efforts areas. The division weights artillery support to the main effort. The corps positions its MLRS and 155-millimeter, SP battalions to support the main effort.

    The division establishes PL WATCH as a coordinated fire line (CFL). The division cavalry squadron is forward of the division's main body.

    After the division cavalry squadron withdraws, PL CLOSE becomes the division CFL. The corps fire support coordination line (FSCL) then moves to PL COLLAR from PL TURTLE (Figure 4-4).

    The division establishes EA IOWA as the best location for a JAAT or CAS attack on enemy armored forces before they reach brigade AOs. The division establishes, from terrain analysis, that TAI 11 and TAI 21 are likely areas for enemy infantry units to occupy or move through to their LD. Engagement area OHIO is a likely artillery firing area.

    The IPB indicates specific terrain the enemy might use but intelligence-collection operations must confirm or deny enemy movements before or early in the battle. Targeting handoff from corps to division must clearly indicate enemy lines of operation two echelons down.

    The LRSD is the best means to target infantry units moving through rough terrain with cover and concealment. The correct use of sensors augments LRSD efforts. The G3 establishes RFAs around LRSDs.

    Mobility and Survivability

    The division specifies obstacle zones to influence enemy tempo by turning, blocking, disrupting, or fixing enemy formations as part of maneuver. The commander specifies any obstacle-restricted areas. Brigade commanders plan obstacle belts to support the division commander's concept.

    Locations of obstacle zones should allow maximum flexibility to subordinate commanders and should facilitate future operations. Obstacles forward of the BHL facilitate the battle handover.

    In this example, engineers task-organize with armored-light engineer mixes in the 1st Brigade (north) sector and in the 3d Brigade (south) sector (Figure 4-5). The 3d Brigade has one reinforced corps wheeled (W) engineer battalion and a light engineer company.

    As the main effort, the 3d Brigade has the most engineer work to execute. It receives priority of division engineer support from the CS equipment company and the one combined engineer battalion.

    The 1st Brigade, as a supporting effort, receives one corps engineer wheeled battalion and an AASLT engineer company (-) in support. The 2d Brigade, in the center, has an AASLT engineer company plus one AASLT platoon from the engineer company with the 1st Brigade. This platoon has an on-order mission for attachment to the division reserve AASLT battalion.

    Priority of effort in the division's close operation is to survivability, then countermobility, then mobility. Behind the division engineer work line (EWL) to the division rear the priority of effort is to mobility (to facilitate movement), then survivability.

    Priority of support forward of PL STAR is to the 3d, 1st, and 2d brigades, then to DIVARTY. Priority of support behind PL STAR is to the aviation brigade, DISCOM, then the reserve.

    The division commander designates turn, block, and fix obstacle zones for his brigade commanders. These areas graphically convey the division commander's intent for tempo and maneuver.

    The brigades establish turn, block, fix, or disrupt obstacles as needed. The total effect of their zones must satisfy the division commander's intent for the obstacle area.

    NOTE: The corps or division did not identify any disrupt obstacle areas in this scenario.

    The division directs placement of fixing areas at the trailing edge of EAs or TAIs to hold enemy forces and increase their vulnerability to deep attack. The division specifies a turning area and reserve target for the one hard-surface road or armored approach.

    The division commander wants to influence the enemy to move into the built-up area and away from the economy of force brigade. The division specifies one large blocking area along PL DOG to stop the enemy short.

    The division also establishes a second defense line in the 1st and 3d Brigade areas forward of PL STAR. These must contain enemy penetrations. The division then specifies obstacle-restricted areas (ORAs) to cover planned LZs for the division reserve.

    Situational obstacles include ground- and air-emplaced FASCAM. The division and brigades use these obstacles (if they have release authority or gain release approval from the appropriate commander) to react to unexpected enemy initiatives as the battle unfolds. If the corps commander delegates release of these obstacles, he can direct that the release authority not go below a certain level of command.

    The DST reflects situational obstacles. The G3, engineer, and assistant fire support coordinator (AFSCOORD) develop FASCAM Class V requirements during COA war-gaming. If requirements exceed the established controlled supply rate (CSR), the division must ask the corps to change the CSR. If the corps disapproves or the division fails to ask, the division will not have the required amount of munitions.

    Obstacle zones to the rear of PL CASTLE (the EWL) are for subsequent positions to contain enemy tactical successes. The two areas between PL DOG and PL STAR provide defense in depth. The division plans these areas to support the division-level maneuver and tempo concept for both friendly and enemy units.

    Air Defense

    The B Battery (-) supports the 3d Brigade, which is the division's main effort. One of-its Stinger sections is initially in DS to the cavalry screening force and, on order, becomes attached to the division reserve battalion.

    The 1st Brigade, as a supporting effort, receives ADA support from Battery A (-) in a role. One task-organized platoon consisting of an Avenger/Stinger section from A Battery is in DS to the 2d Brigade. One Stinger section from A Battery is OPCON to DIVARTY.

    Avenger systems and the majority of the Stinger sections locate well forward in the brigade areas. Stingers counter enemy CAS and attack helicopter operations at the FLOT.

    Stinger teams provide protection to critical assets such as reserve forces, artillery radars, supporting MLRS, the DSA, or attack helicopter staging areas deep in the division's rear area. They lack supporting organic ADA support and, therefore, must rely on overlapping incidental corps ADA coverage, passive AD measures, and counter air operations for protection against enemy air attack threats.

    Combat Service Support

    The DISCOM headquarters, MSB, and corps support units locate in the DSA. Units may cluster tightly when the enemy poses a significant special operations or infiltration threat; they normally disperse widely when the threat potential is lower. Supply distribution is throughput when possible.

    Corps support units, such as a mobile army surgical hospital (MASH) or a corps support battalion, may locate in the division's rear area. They provide area support to the division and other corps units in division AOs.

    The FSBs locate in brigade rear areas near specified MSRs. (See Figure 4-6.) In the defense, FSBs stockpile large quantities of Classes I, IV (Barrier Material), V, and VII supplies on pallets or trailers in brigade support areas (BSAs). Battalions stockpile supplies on the ground in their areas.

    Consumption of small arms munitions in an area defense will be high. Resupply by vehicle will be difficult during the fight because of the terrain, limited road networks, and enemy fire. Units that stockpile supplies assume the risk of losing them if the unit is overrun by the enemy.

    Air assault battalions on the ground do not have the transportation assets to move excessive stock-piles of supplies. Resupply by air, using prepackaged push packages, to unit supply points (SUPPTs) is the norm.

    Landing zones serve as SUPPTs, patient collection points, and ambulance exchange points for MEDEVAC. They should be close to road networks so resupply and evacuation can continue despite the weather or enemy actions. This type of operation requires prior aeromedical evacuation planning and coordination.

    The MSB and FSB maintenance teams go forward to brigade and battalion AOs to repair weapons systems and vehicles that can be quickly returned to operation. Evacuating equipment to the MSB in the division rear area or directly to the corps occurs expeditiously for equipment that requires extensive repairs. When possible, units receive maintenance floats to maintain maximum combat power. Units recover and move nonrepairable weapons and vehicles to maintenance collection points in the BSAs.

    The rear CP establishes and monitors road movement in the division rear area. When the terrain offers few roads, the DTO has to consider the repair-forward concept and air resupply when he develops the plan. The DTO tightly controls road use to support the division's concept of operations. Although strict, the plan allows for vehicle infiltrations for C2 , signal, medical, and engineer purposes. Container delivery system techniques using tactical airlift (C-130 aircraft) or medium-lift helicopter support allow for steady CSS flow.

    The division G4 develops a road network to support CSS operations. He then coordinates with the G3 for tactical movement route requirements.

    The G4 develops a traffic circulation and control plan and a sustainment construction list for roads, helipads, and airfields. The G3 approves the plan and the G4 coordinates it with the DISCOM, PM, and supporting corps engineers. Necessary helipad and road upgrade, repair, or construction begin as early as possible.

    Nuclear, Biological, and Chemical

    In this example, the corps attaches one corps smoke-decontamination chemical company to the AASLT division for the defense. The enemy possesses artillery and rocket-delivered chemical munitions. Therefore, decontamination is the NBC priority.

    Division units establish alternate sites to support decontamination operations if the enemy achieves contamination success in the division's main effort area or DSA. The dual-purpose platoon prepares the alternate sites as platoon sites for deliberate decontamination by the dual-purpose platoon in the division rear area.

    One chemical decontamination squad operates each alternate site to support hasty decontamination operations. Infantry units conduct personal and hasty decontamination operations, undergoing deliberate decontamination when time and situation permit.

    Units that have medical treatment facilities support perform patient decontamination. Medical personnel supervise patient decontamination procedures while providing care to casualties.

    One chemical platoon provides smoke support in a DS role to the main effort. The brigade commander develops and coordinates smoke support requirements with division and adjacent brigade commanders. Class V smoke pots meet requirements for other brigades, DISCOM, aviation elements, artillery, deception, and OPSEC. Units can also use artillery or mortar-delivered smoke munitions. The smoke plan should consider smoke operations for OPSEC reasons.

    Battle Command

    The division TAC CP locates forward in the MBA. Its location should be near the brigades' rear boundary and be masked by terrain for OPSEC and deception.

    The TAC CP will not always locate with the main effort if the enemy has a significant SIGINT capability. From a position between the main effort and the supporting effort brigades, the TAC CP can control and support the main fight.

    The main CP locates near the aviation brigade (the alternate division CP) and reserve, which enhances security against enemy infiltrations. From there, it can adequately support synchronization, concurrent operations activities, and deny enemy SIGINT collection. It is also beyond the range of most enemy artillery. The rear CP collocates with the DISCOM CP in the DSA.


    Defending to Defeat Enemy Forces

    The AASLT division has the ability to defend in depth to defeat enemy forces. This differs from terrain retention in that the focus is on attriting the enemy force. The defenders can use terrain within the sector to obtain an advantage, but terrain retention is not the defense goal.

    As the defender, the AASLT division retains some initiative because it does not become decisively engaged on a specified line. It accepts decisive combat when and where it will support the destruction or defeat of the enemy force.

    The division uses terrain, reinforced by prepared positions and obstacles in depth, to canalize the bulk of enemy combat, CS, and CSS assets into EAs. Ground, artillery, and aerial fires initially destroy the enemy throughout the depth of his avenues of approach. Direct fires and obstacles fix enemy forces for destruction by artillery, mortar, attack helicopter, and USAF aircraft fires.

    Decisive engagement between infantry forces is not the desired method for defeating the enemy. Friendly units become decisively engaged only when needed to influence enemy movements.

    The AASLT division can defend against an armored force, an infantry force, or a combination of forces. The AASLT division defends in depth from prepared positions.

    Against armored units, prepared positions orient on the principal avenues of approach. Rough terrain canalizes heavy forces on the roads, precluding enemy bypass or envelopment of defensive positions. Alternate and supplementary prepared positions compensate for different enemy COAs or unforeseen penetrations. Assault helicopters give the defending division a mobility advantage when these assets can be employed.

    The AASLT division conducts a mobile defense as a division operation by positioning approximately one brigade forward as the fixing force. It then uses the remainder of its combat power as the striking force.

    The division can also participate in a corps or JTF mobile defense in one of three ways:

    1. The AASLT division can be forward in an area defense.

    2. The AASLT division can be the corps or JTF reserve with a mission to air assault a force on a counterattack mission.

    3. The AASLT division can be the corm or JTF strike force (they would best do this with an armored or mechanized force).

    Properly using NAIs and decision points (DPs) make possible long lead times for repositioning forces before enemy contact. Once units come in contact, repositioning units becomes difficult and risky. Repositioning is feasible against armored forces only between prepared positions, using helicopters. This requires a large engineer force and lengthy preparation time and places the helicopters at higher risk levels. Therefore, AASLT units usually disperse to numerous prepared positions and seldom move after contact. Because helicopters may not be able to reposition these units, they may find that enemy forces bypass or isolate defending forces.

    Against enemy infantry forces, AASLT forces may prepare strong forward defenses with reserves in a second line or in blocking positions. This is a classic linear defense tending toward heavy losses or disaster if ruptured or penetrated.

    If the enemy infantry force significantly outnumbers the defender, the AASLT division may adopt a defense in depth oriented on destruction of the enemy force. Defense in depth is also effective when tanks support a larger enemy infantry.

    At times, defenders may establish blocking positions with smaller defensive positions. Security operations, with indirect or aerial fires support, cover all gaps.

    Units plan for but minimize movement between positions to prevent subordinate units from being overrun and destroyed. Planning for these moves includes coordination and synchronization of counterfires, disengagement, and movement fire plans.

    Repositioning supports deception plans and shapes battlefield engagement conditions. The feasibility and number of prepared subsequent positions depend on time available, engineer assets, the maneuver headquarters' ability to plan and designate positions in depth, and the infantry division's movement capacity or ability. Helicopters, tanks, or tracks move troops when possible.

    Defending units usually allow the enemy to move along designated routes from one EA to another. Air and artillery fires are the primary means of destruction. Division and brigades emphasize massed fires such as time on target (TOT) and JAAT missions.

    The AASLT division normally conducts this defense in terrain which affords infantry forces cover, concealment, and protection but which also has open maneuver space for armored forces. Terrain and obstacles force the enemy into EAs.

    Prepared defensive positions around EAs fix enemy forces so air and artillery fires can effectively engage them. As surviving enemy forces move into subsequent EAs, the division reengages them with fire.

    Units select final blocking positions just forward of brigade rear boundaries, designating some key blocking positions as strongpoints. If necessary, the division may reorganize selected engineer units as infantry for additional strongpoints to strengthen the defense.

    Once engineer units receive the mission to reorganize as infantry, they will have difficulty in reversing the process during combat operations. They may have to move to the division rear area to reconstitute as an engineer unit.

    The division commander envisions a tempo and overall conduct for the battle through the depth of the battlefield. He specifies large general areas as blocking positions for the brigades.

    Division-specified general areas do not require brigades to physically locate all forces in battle positions. But, they must position adequate forces in battle positions to accomplish the commander's stated intent for maneuver.

    Operations overlays reflect general fortification symbols to establish a primary orientation for the defense and to graphically establish engineer work priorities. The division may specify strongpoints with or without a minimum unit size when deemed critical to division operations.

    The brigades still plan battles in their sectors between lateral boundaries and designated division engagements. General blocking positions for brigades are not meant to be restrictive. They express the division commander's vision for tempo and maneuver.

    Blocking positions also synchronize the brigades for division fights and facilitate planning of air- and ground-delivered fires. Fires are critical; they are the primary method of destroying the enemy.

    The division plans EAs to focus on timed and massed artillery, aviation, and USAF fires. The division commands the brigades but does not micromanage their plans or the battalion's operations.

    The division does control the brigades so they conform with the division's maneuver, tempo, and synchronization. This may appear to be restrictive to the brigades, but it is necessary to gain benefits from synchronization and synergy.

    The real danger lies in a division plan which fixates on one enemy COA. Intelligence must confirm or deny all possible enemy COAs.

    The division plan focuses on the most probable enemy COA, then determines easy transitions to other possible COAs. Division G2 personnel play the uncooperative enemy during COA development and war-gaming.

    Mobile defense orients on destroying the enemy by using a combination of fire, maneuver, offense, defense, and delay. The defender places minimum forces forward and creates powerful strike forces that catch the enemy as he attempts to overcome defense forces.

    The defender delays the enemy, causing him to focus on the wrong objective, overextending his resources, and exposing his flanks. This leads the enemy into a vulnerable posture in terrain that diminishes his ability to defend against a larger, mobile strike force's counterattack.

    The mobile defense sets up large-scale counterattacks that allow the defender to do four things: destroy enemy forces, gain and retain the initiative, transition to the offense, and move into exploitation and pursuit operations.

    In the following example, a neighboring hostile nation is threatening to invade a developing country friendly to the US. The invasion appears to be imminent.

    Diplomatic efforts to resolve a long-term border dispute are at a stalemate. The hostile nation has already begun mobilization and continues to escalate armed forces along the adjoining border.

    The threatened country formally requested US military intervention under the provision of a long-standing treaty agreement. In response to the country's request and the potential adverse consequences of the hostile country becoming the regional dominant power, The National Command Authority (NCA) directs the deployment of a JTF into the crisis area as a show of force.

    The JTF's maneuver forces consist of an AASLT division with an attached armored brigade. The AASLT division, executing its emergency deployment sequence, begins air deployment into the host nation within hours of notification.

    The attached armored brigade closes into the division lodgment area within days of notification, using strategic sea and air lift capabilities. The lodgment is near the only airport capable of handling C-141 and C-5A aircraft within the disputed area. Forces currently are preparing to move forward from the lodgment area to establish defensive positions in support of HN forces.

    Intercepted high-level message traffic reveals that the hostile country is planning to begin its invasion after mobilization. The invasion force's mission is to rapidly push as far forward into the disputed area as possible and secure selected objectives.

    On securing objectives, the government intends to appeal quickly to the United Nations (UN) for a cease-fire to negotiate a favorable border settlement. The hostile government is gambling that this action will result in obtaining new territory rich in natural resources, demonstrate its country's defiance of US support, and establish it as the dominant regional power.

    The hostile country has significantly increased its offensive capability over the host nation in the past four years. Its ground forces comprise four active infantry divisions, a border defense force, and one separate tank regiment that recently received an upgrade of T-72 tanks.

    Each infantry division includes two infantry regiments and one motorized rifle regiment (MRR) with supporting artillery at both regiment and division levels. A small, aging fleet of aircraft (fixed wing) limit the air force, at best, and should not present a significant obstacle to deployed JTF forces. However, hostile forces have enough helicopters to lift two battalion-size units in a single lift.

    The host nation has three infantry divisions and an internal border security force. Two of the three divisions are active. The third, an auxiliary division, receives reserve personnel manning during national emergencies.

    Border security forces have limited quantities of armored vehicles. The country's air force is comparable to that of the hostile air force.

    Anticipating an invasion, the host nation has deployed both of its active divisions along the threatened border to reinforce border security forces. Increasing incidents of border violations have increasingly resulted in engagements. These violations appear to have been probing missions to identify force density and unit locations along potential invasion routes.

    Terrain between the two countries is mountainous. One major valley system has natural mobility corridors that support motorized vehicles. Vegetation varies from sparse in low, open areas to double-and triple-canopied forests in jungle and mountain areas.

    The JTF commander intends to defeat the invasion force by establishing his AO to the rear of the host nation's existing border defensive positions along the main invasion corridor. He intends for the host nation to establish initial contact with lead invasion forces before committing JTF ground forces in direct contact. This action will demonstrate the invading country's aggression and the host nation's resolve against the invading country.

    Once the invasion begins, the JTF commander intends to quickly develop the situation, contain the main invasion force, and destroy enemy units with swift, overpowering forces. After they stop the invading forces, JTF elements will quickly transition to the offense, forcing the enemy to withdraw and reestablish the recognized border within the JTF's area of operations. Quick success will defeat the enemy's will to continue aggression.

    During this operation, activities must not interrupt airport activities within the lodgment area. Once the JTF reestablishes the border and all countries cease hostilities, the JTF will rapidly deploy.


    To destroy the invasion force, the division commander establishes a mobile defense along the main invasion corridor behind the host nation's border defensive positions. One brigade positions forward into two battle positions to defend in sector to delay advancing forces, to prevent infiltration within the division's sector, and to attrit the enemy. This will slow the enemy's advance, commit his reserve forces early, and overextend his main attack (Figures 4-7 and 4-8).

    The 3d Brigade establishes a blocking position to the rear of the forward brigade. This fixes enemy forces, creating the opportunity for the 2d Brigade and the armored strike force to maneuver to destroy the contained forces.

    Lodgment security is vital to the JTF operation; a security force of two AASLT battalions with augmentation from host forces protects it. The desired end state is to destroy the attacking enemy's invasion forces and quickly transition to the offense, forcing withdrawal to the hostile country and reestablishing the border.

    The mobile defense strike force consists of the 2d AASLT brigade (-), the armored brigade, and two AHBs. The force locates behind the blocking brigade to rapidly attack and destroy enemy forces in designated objective areas forward of the blocking positions. Two infantry battalions provide lodgment security during the operation.

    The JTF initially limits the depth of division deep operations because of the JTF-imposed "no cross-border operations" restriction. Close coordination with in-place HN border forces results in designating EAs forward of the division.

    Deep fires neutralize enemy artillery support, decreasing follow-on forces' OPTEMPO. This provides time for defending brigades to concentrate combat power without interference by follow-on reinforcements. The aviation brigade disrupts and destroys enemy follow-on motorized and armored forces supporting forward defending brigades. Deep fires and obstacles provide time and help seal off the contained enemy force, supporting strike force attacks.

    The division cavalry squadron screens forward of mortar fires. Available CAS and attack helicopters the two defending brigades, establishing contact with the HN border security forces forward of the division's sector. The cavalry gains contact with advancing invasion forces that penetrate border security and maintains contact to provide early warning for the lead brigades.

    As the enemy approaches the division's sector, the division initiates deep fires to disrupt, attrit, and alter the lead regiments' tempo. Maintaining contact with the enemy, the cavalry delays to the BHL, moves through the defending brigades, and establishes a rear flank screen. This screen locates behind the forward brigade sectors to detect infiltrating enemy forces that threaten the lodgment area.

    Designated EAs within the brigades' defensive sectors facilitate massing of combat power during the delay to attrit the enemy. The 1st Brigade establishes mutually supporting positions constructed in depth in its sector to detect and impede enemy movement.

    Defensive positions and integrated obstacles create EAs, allowing massing of available artillery and augment supporting fires.

    The 3d Brigade contains penetrating forces by occupying blocking positions to the rear of the forward brigade and sealing off the division sector. This causes the enemy to focus and concentrate his forces on the 3d Brigade's blocking positions.

    As the enemy attempts to penetrate the blocking positions, his flanks become exposed and vulnerable for counterattack. The 2d Brigade and the armored brigade then conduct a swift counterattack into the enemy's flank, destroying the forces forward of the blocking positions in designated objective areas.

    The two AASLT battalions, one each from the 2d and 3d brigades, provide lodgment security, which prevents interruption of airfield and lodgment support activities from infiltrating forces. One company within the lodgment is the division reserve.

    After destroying the enemy's main attack in the division sector, the division rapidly transitions to the offense, clearing the sector of remnant units, forcing enemy withdrawal, and halting his invasion. Once the existing border is reestablished, the division closes in the lodgment area and prepares for deployment.


    Intelligence for the mobile defense focuses on determining the enemy's precise location, strength, and intent. This information increases the effective-ness of the striking force.

    The long-range surveillance teams (LRSTs) locate to observe NAIs, TAIs, and DPs. Ground surveillance radar teams provide early warning and support forward maneuver brigades and units providing lodgment security.

    The division's collection plan supports the developed PIR critical to the targeting process and the enemy's destruction. The intent is to confirm the enemy's main attack and the location of his follow-on forces.

    Fire Support

    Fire support assets mass fires to disrupt and destroy moving enemy units in EAs. The division FSE coordinates the positioning of all fire assets so massed fires and TOT missions are possible across the division front.

    Fire support weights the main effort. (The main effort in a mobile defense is the striking force.) When striking forward of conventional artillery range, the commander plans for the forward displacement of artillery assets or the incorporation of artillery into the striking force.

    Mobility and Survivability

    The division commander specifies general obstacle zones to fix the enemy, increase attrition, cause enemy supporting artillery to deploy, and to set and slow the enemy's tempo. The division specifies disruption zones behind EAs to enhance targeting and deep fires and to slow the tempo of follow-on forces.

    The commander designates one fixing zone forward of the 3d Brigade to assist in the enemy's containment. The obstacle plan facilitates delaying enemy forces and develops the conditions that will cause the enemy to expose his flanks, providing opportunity for strike-force attacks.

    Priority of effort for the striking force is normally mobility, then countermobility. Priority of effort for the more static defending forces is normally survivability, then countermobility.

    Air Defense

    The division is operating in a low air threat environment. The division attaches Stinger teams to each maneuver brigade, and the battalion (-) locates within the lodgment area. These assets provide integrated ADA coverage against potential enemy heliborne operations.

    Combat Service Support

    The more intensely the striking force attacks the enemy from the main defensive positions, the greater will be their need for supplies. In this example, FARPs can be in the division's AO, but the armored force may need logistic support forward in the EA.

    Battle Command

    Division rear and main CPs locate within the lodgment area. The rear CP controls division activities within the lodgment, including security. The TAC CP locates forward in the division sector behind the blocking brigade.

    Forward positioning helps synchronize the delay of the two forward brigades and the control of the armored brigade, when committed. The echelon executing the mission (normally the TAC CP) retains command of the striking force.

    Transition to the Defense

    While the defense's immediate purpose is to defeat an enemy offensive operation, a force may have to defend because it is unable to continue the attack. According to FM 100-5, this is a point where the strength of the attacker no longer exceeds that of the defender and beyond which continued offensive operations risk overextension, counterattack, and defeat.

    A force normally defends to develop favorable conditions for an attack or to provide an economy of force in one area to mass overwhelming offensive combat power in another. Specifically, the defender may have to--

  • Buy time.
  • Hold a piece of terrain to facilitate other operations.
  • Keep the enemy preoccupied in an area.
  • Build up forces.
  • When attacking units cease their attack and must defend, they have two basic options. One, commit forces and push forward to claim enough ground for a security and or CFA (that is, beyond the majority of enemy artillery range fans) from which to defend. Two, fall back to defensible terrain to establish a security area, establishing the FLOT generally along the attacking force's line of advance of final objectives.

    In both options, the FLOT is the forward edge of the security area. The FEBA is the forward edge of the main defensive area.

    Unfortunately, the first option results in loss of additional personnel and equipment and expenditure of more resources. The security area often lacks depth. In addition, the enemy force will probably accurately template the friendly FEBA trace and engage with artillery. These actions increase loss to friendly personnel and equipment.

    In many cases, option 2 is better. Commanders pull back the bulk of their forces to defensible terrain. They establish the MBA on ground the attacking force already owns rather than under the threat of enemy artillery.

    The forward edge of the security area, which is the FLOT, remains along the line of contact. METT-T and the operational plan determine the depth of the security area.

    The AASLT division has the capability to be a corps or JTF counterattack force or to conduct a defense forward in the corps' AO. (See Chapter 4 of FM 71-100-2.)

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