CHAPTER 4
INFANTRY DIVISION DEFENSE
This chapter provides some examples of how infantry divisions integrate and synchronize combat, CS, and CSS assets for defensive operations. Corps, divisions, and brigades use a variety of tactics and techniques to execute a defense. The tactics and techniques discussed in this chapter describe only one way a division may conduct these 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 defense must be conducted aggressively to wrest the initiative from the attacker. The commander can accomplish this by mixing defensive and offensive tasks in his defensive concept of operations. Each concept of the operation must clearly identify how to seize the initiative through a defeat mechanism. The concept must also envision a sequel to maintain the initiative and exploit tactical successes.
The defense may be one battle or a series executed over time. Subordinate units are given defensive tasks to contain or trap an enemy force, deny area access, attrit the enemy, or act as an economy of force. Others are given tasks to attack or counterattack. The intent is to achieve conditions to gain and maintain the initiative for decisive offensive action. Without a compelling reason to defend, we attack.
There are two forms of defense--mobile and area. The mobile defense aims to destroy enemy forces through a decisive counterattack. It is more lethal since it concentrates the bulk of combat power upon the enemy force, producing a decisive result. It requires a large mobile counterattack 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 must have the freedom and capability to maneuver.
The area defense usually orients on retention of terrain. Forces are deployed laterally and in depth, retaining terrain rather than focusing on the enemy. When defending against armored forces in close terrain, area defenses are normally situated to defend on high speed avenues of approach. Area defenses are best in rough terrain, or when specific terrain must be retained, the sector lacks depth, or the defender lacks sufficient maneuver potential compared to the enemy. When operating independently, in the jungle or when encircled, units may find themselves in a perimeter defense. (See example in Chapter 8.)
See Chapter 3 for guidance on the current chemical and nuclear weapons policy.
All defenses must use terrain properly. Terrain is a force multiplier for infantry units. It facilitates massing combat power at the point of decision 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. Terrain also provides cover and concealment for the defender.
All defenses must conduct security operations. The defender has the advantage of terrain, but initially lacks the initiative. Defenders accept risk in economy of force areas in order to mass for combat power elsewhere. Security operations prevent surprise and reduce the risk of bypass or encirclement of the main effort.
Defense in depth provides flexibility and dispersion to the defender 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.
- Employment of counterattacks.
- Use of engagement areas, barriers, and improved positions to canalize, delay, or attrit in depth.
- Attack of the enemy's flanks and rear.
- Deception plans.
Mutual support integrates the fires of the total force. It allows a dispersed force but focuses combat power.
The infantry division is a tactically mobile force with respect to terrain. 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 infantry division, it can conduct an area defense in appropriate terrain to block dismounted enemy movements. It can also defend against an enemy infantry armored force with small organic tank units.
Examples in this chapter discuss both area and mobile defenses. The mobile defense in warfare is not a viable mission for light divisions without aviation, anti armor, transportation, and armored augmentation. An armored brigade in support of a light division constitutes a light-armored operation, discussed in Chapter 7. Only the air assault division can conduct mobile defense operations without augmentation.
The defeat mechanism for armored attacks is a combination of artillery, attack helicopters, USAF aircraft, integrated obstacle plans, and the division's medium and heavy antitank systems. Against enemy infantry forces, the defeat mechanism is artillery, mortars, air support, and infantry.
DEFENSE IN SECTOR: TERRAIN RETENTION
In this example, the corps defends with one infantry division and one armored division abreast and an armored cavalry regiment covering force. It has a separate mechanized brigade in reserve. The corps is defending against part of an enemy corps.
The enemy corps is a secondary effort. It is expected to 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 numerous small built-up areas. Vehicle traffic is mostly restricted to improved roads and a few wide areas in the 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 (see Figure 4-1). The infantry division has been given a defensive sector dominated by high rugged hills and a small built-up area. One improved highway runs the length of the sector. The infantry division has the mission to defend in 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 armored cavalry regiment (ACR) is the corps covering force. The corps reserve (a separate armored brigade) is positioned behind the armored division.
The cavalry regiment 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 and then counterattack with his separate mechanized brigade to destroy remaining enemy formations in zone and restore the FEBA.
Corps deep operations initially focus on distant, uncommitted enemy forces. Deep operations target any mechanized or armored units moving forward to exploit penetrations. The remainder of this section discusses the specific operations of the infantry division defense in sector (terrain retention).
Maneuver
The infantry division defends in sector with three brigades on line along PL DOG. (See 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 is expected to try to infiltrate around built-up areas. An enemy supporting attack is expected in the north. The division's task organization for this example is provided at Figure 4-3. 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 infantry units' freedom of maneuver. The proactive counterfire operation as a deep operation is defined by target type, 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 by destroying artillery, attriting infantry formations, and desynchronizing the enemy's attempt to mass. Attacking enemy divisions are echeloned in depth as they approach the FEBA. Leading enemy regiments, the division's close fight, are engaged by brigades. Follow-on enemy regiments and reserves are division deep targets. The corps attacks other enemy divisions as the enemy moves forward.
To delineate deep attack responsibilities for these ground maneuver targets, the corps and division specify phase lines which separate their close and deep operations areas. The phase line creates a point where handoff coordination is accomplished between echelons. It does not create separate areas where uncoordinated concepts of the operation are executed. The maneuver concept of the operation, intent, and deep operations' desired results between the higher and lower commanders are coordinated and mutually supporting. The senior commander specifies his intent for the deep operation in his OPORD. 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 handoff and synchronization of intent are required at the specified phase. This is especially true for intelligence collection and targeting.
The division commander has reserved proactive counterfire for the deep operation. He has reserved enemy artillery units as a specified target type. These enemy artillery units are targeted and attacked anywhere on the battlefield--regardless of the specified phase line for moving enemy infantry or armored units.
The primary division deep weapon systems are MLRS (if available), tube artillery, fixed-wing AI, and attack helicopters. These are division assets or corps-provided support.
Close Operations
Close operations are fought with mutually supporting positions and integrated obstacles constructed in depth. Infantry operations must contain enemy infantry movements so that they can be engaged with massed artillery and mortar fire. Attack helicopters and CAS augment these fires. Attack helicopters and CAS counter enemy armored forces, especially when massed formations are deployed to exploit success. Enemy tanks are expected to be used principally as infantry fire support due to limited maneuver space. Brigades position TOWs and Dragons to destroy tanks supporting infantry attacks. Since tank and mechanized units are committed to exploit penetrations, antiarmor fires are planned in depth.
Area defense focused on terrain retention relies upon using terrain, obstacles, and massed fires to stop and kill an attacking enemy. Fires in depth desynchronize the enemy attack plan, but success is achieved by overwhelming massed fires at the FLOT.
Because the infantry division will probably not have sufficient mobility to move faster than an attacking enemy, the initial defense at the FLOT is crucial. Thorough reconnaissance to situate the defense is critical. Any repositioning of units to alternate or supplementary positions must be completed prior to the arrival of enemy main body or preparation fires. These moves are triggered by events collected by the deep intelligence operations. A decision support template must be developed and used.
This type of defense may be considered high risk since it orients on retaining terrain. Risk can only be minimized by allowing the maximum possible depth for defense in front of the retained terrain. Massed fires must be used in conjunction with obstacles to create engagement areas (EAs) which deny momentum and initiative to the enemy. Obstacles cause the enemy to mass and thereby increase the effectiveness of fires.
Rear Operations
The division cavalry squadron initially screens forward of the line of contact behind PL WATCH. On withdrawal, it rejoins the aviation brigade to screen behind committed brigades to locate infiltrating and penetrating enemy units. On order, it defends to block or contain the enemy so that the enemy can be attacked by fires.
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. Division CSS elements which cannot be adequately protected locate in the corps rear area.
Security Operations
The corps armored cavalry regiment conducts covering force operations forward of PL WATCH until withdrawn. Initially, the division cavalry squadron screens forward of the main effort, behind PL WATCH. Division tasks the brigade in the north to screen forward along PL WATCH. The mission is to screen since the light 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, a screen is established for early warning first and attrition second. Artillery fires and CAS are planned 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 cavalry 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 would be expected in the 3d brigade area attempting to bypass the city to the north.
The battle handoff line for the screening force is PL CLOSE. The defending brigades send out security elements as far out PL CLOSE. They must mark routes and provide fire support for the retrograde. The handoff line partially defines the division's forward security area.
The enemy can be expected to attempt infiltrations in support of every attack to bypass or penetrate the main defenses and 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 withdrawal from the screening mission, the division cavalry squadron rejoins the aviation brigade in the aviation brigade sector. The aviation brigade performs security operations behind the brigades. The mission is to discover and contain or block enemy infiltrations or penetrations into the division rear area. In this scenario, the enemy executes infiltration and bypasses resistance in every attack. The aviation brigade was given this security mission because it controls the division cavalry squadron. The division intent is to employ attack helicopters in support of the brigades and the deep operation.
Reserve Operations
It is difficult for an infantry division to maintain a large reserve in this mission. The division reserve must have a dedicated movement capability, either organic or provided, to react in a timely manner.
In this example, the division has one infantry battalion in reserve and dedicated lift assets. Movement of reserves must be planned carefully due to vulnerability to indirect fires and air attack while moving. Selected reinforcement routes should provide cover and concealment while rear area security and reconnaissance operations decrease the probability of enemy stay-behind or special forces observing reserve locations. Electronic warfare or fires directed at enemy or fire control HQ can degrade the enemy's ability to attack the reserve. Finally, artillery and smoke fires may be required to cover reserve deployment and employment.
Intelligence
Military intelligence assets are deployed forward in brigade areas to range beyond the FLOT. The collection company is normally task-organized into three teams. These teams control voice and signal intelligence (SIGINT) collection for the division. In this example, one platoon-sized team supports the secondary-effort brigade and the company (-) supports division main-effort brigade. One ground surveillance radar (GSR) squad is attached to each brigade. The fourth GSR squad is attached to the cavalry squadron and initially supports the cavalry screening force and then the rear area screen. The GSRs orient on supporting brigade operations by detecting enemy infantry infiltrations.
The LRSDs are deployed to observe NAIs, TAIs, or decision points (DPs) for targeting purposes. Intelligence collection tasks and guidance are planned and prepared by division G2 based upon the G3's guidance.
The LRSD teams are deployed by the G3. Teams are deployed with the cavalry screening force and infiltrate to assigned dispersal areas. Teams select positions that provide long-range observation of assigned areas.
The remainder of the interrogation and surveillance (I&S) company is located at the division EPW collection point.
The division G2 coordinates intelligence handoff for enemy units from corps to division and division to brigade. Enemy units, NAIs, and TAIs are observed and monitored according to the priorities established in the collection plan. Division G2 at the TAC CP tracks enemy units into brigade AOs for targeting and situation development purposes. In this example, PIR collection requirements are in order of priority.
- Location and movements of enemy artillery units.
- Location and movement of follow-on divisions.
- Location and movement of enemy armored or mechanized forces.
- Location of enemy division-level facilities.
Fire Support
Artillery, EW, and TACAIR support are organized to provide massed fire support to defeat enemy attacks in both the main and supporting efforts areas. Artillery support is weighted to the main effort. Corps MLRS and 155-millimeter SP battalions can be positioned to support the main effort area.
The division establishes PL WATCH as a coordinated fire line (CFL) while the division cavalry squadron is forward. After withdrawal, PL CLOSE becomes the division CFL. The corps fire support coordinated line (FSCL) is then moved to PL COLLAR from PL TURTLE. (See Figure 4-4.)
The division establishes EA TANK as the best location for a joint air attack team (JAAT) or CAS attack on enemy armored forces before they reach brigade areas of operations. The division establishes TAI 11 and TAI 21 from terrain analysis as likely areas for enemy infantry units to occupy or move through to their LD. The EAs TUBE and ARTY are likely artillery firing position areas.
The IPB indicates specific terrain the enemy may use but intelligence collection operations must confirm or deny enemy movements prior to or early in the battle. The targeting handoff from corps to division must clearly indicate enemy lines of operation two echelons down. The LRSDs are the best means to target infantry units moving through rough terrain with cover and concealment. Sensors are used to augment LRSD efforts, G3 establishes "no fire" areas around LRSDs.
Mobility and Survivability
Obstacle zones are specified by division to influence enemy tempo by turning, blocking, disrupting, or fixing enemy formations as part of the maneuver. The commander specifies any obstacle-restricted areas. Brigade commanders plan obstacle belts to support the division commander's concept.
Obstacle zones are drawn to give maximum flexibility to subordinate commanders and to facilitate future operations. Obstacles forward of the battle hand-over line (BHL) facilitate the battle handoff.
In this example, the engineers are task-organized with armored-light engineer mixes in the 1st brigade (north) sector and in the 3d brigade (south) sector. (See Figure 4-5.) The 3d brigade has one reinforced corps wheeled engineer battalion and a light engineer company. This brigade, as the main effort, 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, is supported by one corps engineer wheeled battalion and a light engineer company (-). The 2d brigade, in the center, has a light engineer company plus one light platoon from the engineer company with the 1st brigade. This platoon has an on-order mission for attachment to the division reserve infantry battalion.
Priority of effort in the division's close operation is countermobility, survivability, and then mobility. Behind the division engineer work line to the division rear, the priority of effort is to mobility to facilitate movement, and then survivability.
Priority of support forward of PL STAR is to the 3d, 1st, and 2d brigades and then to the DIVARTY. Priority of support behind PL STAR is to the aviation brigade, DISCOM, and then the reserve.
The division commander has designated turn, block, and fix obstacle areas for his brigade commanders. (NOTE: No disrupt obstacle areas were specified in this scenario.) 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 in tent required by the division commander's obstacle area.
Fixing areas have been placed at the trailing edge of EAs or TAIs to hold enemy forces and increase their vulnerability to deep attack. A turning area and reserve target have been specified for the one hard-surfaced 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. One large blocking area is specified along PL DOG to stop the enemy short of PL DOG. A second line of defenses is established in the 1st and 3d brigade areas forward of PL STAR. These must contain enemy penetrations. Obstacle free areas (OFAs) are specified to cover planned LZs for the division reserve.
Situational obstacles include ground and air-emplaced FASCAM. Both the division and brigades may use these obstacles (if release authority is granted) to react to unexpected enemy initiatives as the battle unfolds. Control of situational obstacle assets can be retained at division, passed to subordinate units for planning, or delegated to subordinate units. Situational obstacles are reflected on the division support template (DST). The G3, engineer, and assistant fire support coordinator (AFSCOORD) develop FASCAM class V requirements during COA wargaming. Obstacle areas to the rear of PL CASTLE (the engineer work line) are for subsequent positions to contain enemy tactical successes. The two areas between PL DOG and PL STAR provide defense in depth. These areas are planned to support the division-level maneuver and tempo concept for both friendly and enemy units.
Maneuver, tempo, and fires are partially synchronized by the obstacle plan according to the commander's intent. The expression of this intent is a and maneuver BOS action. The execution is the M/S BOS action. Obstacles are not an engineer only issue. Obstacle areas and targets are based on maneuver concepts.
Air Defense
The division's main effort is the 3d brigade in the south. It is supported by battery B (-). One of its Stinger sections is initially in DS to the cavalry screening force and, on order, is attached to the division reserve battalion. The 1st brigade, as a supporting effort, is supported by battery A (-) in a DS role. One task-organized Avenger/Vulcan/Stinger platoon from battery A is DS to the 2d brigade. One Stinger section from battery A is OPCON to DIVARTY.
Avenger systems and the majority of the Stinger sections are located well forward in the brigade areas. Stingers counter enemy CAS and attack helicopter operations at the FLOT. (Vulcan guns also engage enemy attack helicopters.)
Stinger teams are also provided to critical assets such as reserve artillery radars, or supporting MLRS. Other critical assets such as the DSA or attack helicopter staging areas are placed deep in the division rear area. Because they lack supporting organic ADA support, these units must rely on overlapping incidental corps ADA coverage, passive air defense measures, and counterair operations for protection against enemy air attack threats.
In this example, the enemy has three routes into the sector for air support and attack helicopters. If an air threat to the division rear develops from the flank, the corps ADA brigade must adjust coverage or provide additional assets to the division. Enemy CAS and attack helicopters, directed at the FLOT, remain the most significant air threat to the defense in this scenario.
Combat Service Support
The DISCOM HQ, MSB, and corps-attached or OPCON support units are located in the DSA. Units may be tightly clustered when the enemy poses a significant special operations or infiltration threat or more widely dispersed when the threat potential is lower. Supply distribution will be throughput where possible.
Corps support units, such as medical and class V, may be located in the division rear area. They provide area support to the division and other corps units in the division AOs.
The FSBs are located in the brigade rear areas in the vicinity of specified MSRs and SRs. (See Figure 4-6.) In the defense, FSBs stockpile large quantities of class I, V, and VII on pallets or trailers in the BSAs. Further ground stocks of class I, IV, and V are sited in the battalion area. Consumption of small arms munitions in the terrain retention battle will be high. Resupply will be difficult during the fight due to the terrain and enemy. To facilitate resupply, stockpiles are sited prior to the fight.
Resupply by vehicle may be difficult due to terrain and limited road networks. Resupply by air, using prepackaged push packages, to unit supply points will be the norm. Landing zones must be established for this purpose.
These LZs also serve as medical patient collection points or ambulance exchange points for medical evacuation. They should be close to road networks so resupply and evacuation can continue despite the weather or enemy actions. Aeromedical evacuation planning and coordinating is required for this type of environment. In this example, a mobile Army surgical hospital is located in the division rear area near MSRs. Corps also provides additional air and ground ambulance assets.
Maintenance teams in the MSB and FSBs go forward to repair weapons systems and vehicles that can be quickly returned to operation by use of quick-change assemblies or small parts. Extensive repair work is evacuated to the MSB in the DSA or directly to corps. When possible, maintenance floats are issued to maintain maximum combat power. Evacuation of nonrepairable weapons and vehicles is to the BSAs.
The DISCOM establishes and monitors road movement in the division rear. The repair forward concept and air resupply were considered when developing this plan since the terrain offers few roads. Road use is tightly controlled 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 (C130 aircraft) or heavy-lift helicopter supports allow for steady CSS flow.
The division G4 develops a road network to support CSS operations and coordinates this with the G3 for tactical movement route requirements. The G4 develops a traffic circulation and control plan and sustainment construction list for roads, helipads, and airfields. The G3 approves this plan and the G4 coordinates it with the DISCOM, PM, and supporting corps engineers. Necessary helipad and road upgrade, repair, or construction are begun as early as possible.
Nuclear, Biological, and Chemical
In this example, one corps smoke-decontamination chemical company is attached to the light division for the defense. The enemy is expected to use artillery and rocket-delivered chemical munitions. The NBC priority, therefore, is decontamination. Four dual purpose platoons provide deliberate decontamination support from established sites. Two dual-purpose platoons in DS support the 3d brigade's main effort. One platoon provides smoke and the other, decon. One dual-purpose platoon providing decon in DS supports the 1st brigade. One dual-purpose platoon and the chemical company (-) in the GS role supports the division rear. Alternate sites 2 and 11 are located to support decontamination operations if the enemy achieves contamination success in the division's main effort area or DSA.
These alternate sites are prepared as platoon sites for deliberate decontamination by the dual-purpose platoon in the division rear in the GS role. They may be operated by one chemical decontamination squad to support hasty decontamination operations. Infantry units are expected to conduct personal and hasty decontamination operations. They undergo deliberate decontamination when time and situation permit. Patient decontamination is performed by personnel from the supported unit at medical treatment facilities. Patient decontamination procedures are supervised by medical personnel while providing care to the casualties.
One chemical platoon is designated to provide smoke support in a DS role to the main effort. Smoke may be used to limit enemy target acquisition, conceal friendly movements, and support limited counterattacks in the built-up area. The brigade commander develops smoke support requirements and coordinates with the division and adjacent brigade commanders. Smoke requirements for the other brigades, DISCOM, aviation elements, artillery, deception, and OPSEC are met with class V smoke pots. Smoke is also planned using artillery or mortar-delivered smoke munitions. The smoke plan should also consider smoke operations for OPSEC reasons.
Command and Control
The division TAC CP locates forward in the main effort area. Its location should be near the brigades' rear boundary and 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 economy of force 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 where it can adequately support synchronization and concurrent operations activities, and deny enemy SIGINT collection. It is also beyond the range of most enemy artillery. Security against enemy infiltrations is enhanced by locating in or around the aviation brigade, division reserve, or corps engineer units.
The rear CP collocates with the DISCOM CP in the DSA. The DSA location is normally beyond the range of enemy artillery and multiple rocket launchers (MRLs).
MP Operations
The four MP platoons, three divisional and one corps, possess mobility, speed, and firepower. Their priority missions are rear area security, battlefield circulation control, and enemy prisoner of war operations.
The MPs are given area security and battlefield circulation control missions north of PL STAR from the division rear boundary forward to the brigade rear boundary. One platoon provides exterior security for the DSA by the use of screens, LPs, OPs, checkpoints and road blocks.
The MPs also have an area security and traffic circulation and control mission south of PL STAR from the division rear to the brigade rear boundary. The platoon assigned this mission provides an MP squad on order as a response force to the MP company HQ. This platoon also supports the division reserve battalions' move to the brigade rear boundary.
Other platoons provide area security and battlefield circulation control from brigade rear boundaries to the battalion trains area. One platoon supports the main effort brigade while the other supports the other two brigades. Both platoons provide general support to the infantry brigades; artillery, engineers, and other CS units; and CSS units.
The MP platoons are under division control to support the division first on an area basis and then by mission request priority. Priority tasks are area security battlefield circulation control and then EPW operations. Priority of support is the main effort, artillery movements, DISCOM, other maneuver units, and other CS units. The division reserve becomes the first priority for support when committed.
The division band is attached to the MP company and operates the division EPW compound under the direct supervision of the MP company HQ.
Since this defense 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. Security, counterreconnaissance, and smoke operations are needed to deny enemy direct observation. Additional measures to protect units and increase weapons effectiveness should be adopted as time permits. A stationary defense does not directly challenge the enemy's initiative until decisive combat has begun and should be used only when we can achieve a compelling advantage over the enemy.
DEFENSE IN SECTOR: DEFEND IN DEPTH TO DEFEAT ENEMY FORCE
The infantry division defends in depth to defeat enemy forces. This defense differs from terrain retention in that the mission focuses on the enemy force. Terrain within the sector is used to obtain an advantage, but retention of terrain is not the goal of the defense. The focus is on attriting the enemy through the depth of the battlefield. As the defender, the infantry division retains some initiative in that it does not accept decisive engagement on a specified line. It accepts decisive combat when and where it supports destruction of the enemy force.
The division uses terrain reinforced by prepared positions and obstacles in depth to canalize the enemy into EAs. Direct fires and obstacles fix enemy forces for destruction by artillery, mortar, attack helicopter, and USAF fires. Decisive engagement between infantry forces is not the desired method for defeating the enemy. Decisive engagement is accepted only when needed to influence enemy movements.
The infantry division may defend against an armored force, an infantry force, or a force composed of varied levels of infantry and armored units. Many future enemies will likely have an infantry heavy base structure.
The infantry division defends in depth from prepared positions. Against armored units, these positions orient on the principal avenues of approach. The rough terrain canalizes the heavy forces on the roads, precluding enemy bypass or envelopment of the defensive positions. Alternate prepared positions compensate for different enemy courses of actions or unforeseen penetrations. The use of NAIs and DPs make possible long lead times for repositioning of forces prior to enemy contact. Once contact is made, repositioning units becomes difficult and risky. Against armored forces, repositioning is feasible only between prepared positions using helicopters. This requires a large engineer force and lengthy preparation time. Therefore, infantry units usually disperse to numerous prepared positions, seldom move after contact, and may be bypassed or isolated as a rule.
Against enemy infantry forces, the infantry 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, a defense in depth oriented on destruction of the enemy force maybe adopted. This defense in depth is also effective when the larger enemy infantry is supported by tanks. These tanks are normally organic battalion units in the division or larger units from the corps or army.
The terrain should be restrictive to the degree that it canalizes the enemy's bulk of infantry units, CS, and CSS in valleys and passes. Blocking positions are established sometimes with smaller defensive positions. All gaps are covered with security operations with access to indirect or aerial fires. The enemy initially is destroyed by ground, artillery, and aerial fires throughout his depth on the enemy avenues of approach. Fires and alternate or supplementary positions are then used to destroy and block enemy infantry maneuver through the restrictive terrain to destroy our principal blocking positions. Movements between positions are minimized but must be planned to prevent subordinate units from being overrun and destroyed. These moves must be supported by counter fire, disengagement and movement fire plans. Movements are made by helicopter, tank, or tracks whenever possible.
In all cases, the enemy is allowed to move along designated avenues from EAs to EAs. Air and artillery fires are the primary killers, with division and brigade emphasizing massed fires such as time on target and JAAT missions.
The infantry 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. Defensive positions are selected to force the enemy into EAs. Prepared positions around EAs fix enemy forces so that air and artillery fires can effectively engage them. Security forces cover gaps. As surviving enemy forces move into subsequent EAs, they are again taken under fire.
Final blocking positions are selected just forward of the brigade rear boundaries. Some key blocking positions may be designated as strongpoints. Selected engineer units may be reorganized as infantry if necessary for additional strongpoints to strengthen the defense.
The decision to use subsequent positions as well as the number of positions to use is based on the nature of the enemy force and the defender's mobility. A significant enemy armored threat dictates a defense in depth with minimum movement between positions. Units prepare positions oriented on armored avenues of approach and use a comprehensive obstacle system to force the enemy force into an EA where it can be destroyed. A significant enemy infantry threat requires preparing positions in depth to counter a penetration. A defense in depth with movement to subsequent positions is favored when the enemy has an overwhelming infantry force advantage or significant infantry forces supported by armored units. It is similar to a delay operation, except that the entire force may not move.
Units may move directly to subsequent defensive positions without conducting a delay in between. This repositioning supports reacting to unexpected enemy successes or to other than anticipated enemy COAs. In either case, the repositioning supports the execution of a defeat mechanism based on massed tires into EAs. Repositioning also supports deception plans and shapes battlefield engagement conditions. The feasibility of subsequent positions and their number depends on the time available, engineer assets, maneuver HQ's ability to plan and designate positions in depth, and movement capacity or ability of the infantry division.
The division commander envisions a tempo and overall conduct for the battle through the depth of battlefield. He specifies large general areas as blocking positions for the brigades. Division-specified general areas do not require the brigades to physically locate all forces in the battle positions. The brigades must position adequate forces in the battle positions to accomplish the commander's stated intent for maneuver. General fortification symbols are placed on the operations overlay to establish a primary orientation for the defense and to establish engineer work priorities graphically. Division may specify strongpoints with or without a minimum unit size when deemed critical to the division operation.
The brigades still plan their battles in their sectors between lateral boundaries and between the designated division engagements. General blocking positions for brigades are not meant to be restrictive. They are provided to express the division commander's vision, tempo, and maneuver.
Blocking positions also synchronize the brigades for the division fights, and facilitate planning of air and ground delivered fires. Fires are critical; they are planned to be the primary killer. Division plans EAs to focus on timed and massed artillery, aviation, and air force fires. The division commands the brigades, but does not micromanage the brigade plan or battalion operations. The division does control the brigades so that they conform with the division's maneuver, tempo, and synchronization. This may appear to be restrictive to the brigades, but it is necessary to benefit from synchronization and synergy.
The real danger lies in a division plan which fixates on one enemy COA. Intelligence must confirm or deny the enemy's possible COAs. The division plan will focus on the most probable enemy COA and then provide easy transitions to alternate COAs.
In this example, the corps defends against an enemy corps. The enemy is primarily an infantry-heavy force with motorized infantry and small tank units used for penetrations and exploitations. Its infantry divisions have one organic tank battalion. The enemy corps has one separate tank regiment and one mechanized brigade. The enemy's primary combat power is his indirect fire support. He has large numbers of MRLs, artillery, and mortar systems. Most of these systems have similar or longer ranges than comparable corps systems.
The enemy has an offensive doctrine which in general provides for a main attack to seize or destroy key objectives, a supporting attack to fix enemy forces, and an infiltration to go deep and attack reserve formations and key C2 or CS assets. The infiltrations are preceded by special operations forces and followed by larger formations seeking to bypass resistance at the LD/LC.
The last enemy offensive slowed to a halt after the leading divisions suffered heavy losses. The enemy's weak logistics system is further hampered by constant USAF air attacks. The enemy is currently moving several corps forward to resume the offensive across the entire front. The enemy corps is expected to resume the offensive with its follow-on divisions in a supporting attack for the enemy army.
The enemy is expected to attack with a main and supporting attack in the south against the reinforced 31st Infantry Division. (See Figure 4-7.) The 32d Infantry Division (+) (on the corps left) is the corps' supporting effort. It is reinforced by one separate mechanized brigade and expects to defend against one infiltrating enemy infantry division. The 32d Infantry Division may also have to defend against possible elements of the enemy's supporting attack along the corps' interdivision boundary (between the 31st and 32d divisions). The threat analysis, based on the corps intelligence estimate, was principally driven by the enemy's doctrine and the terrain. The 43d Air Assault Division is the corps reserve.
The corps-controlled security force is the corps' ACR. One cavalry squadron operates forward of the 32d Infantry Division. The rest of the ACR operates forward of the corps' main effort, the 31st Infantry Division (+). On withdrawal, the cavalry regiment reconstitutes in the corps rear area for later commitment by the corps.
The corps commander intends to destroy the enemy main attack by fires. Engagement areas will be shaped by the infantry divisions and limited objective counterattacks by the air assault division. The infantry division on the corps left is expected to defeat the enemy infiltration division and contain the enemy.
The terrain is typically rugged. Numerous valleys and high ridge lines run generally parallel to our lines of operation with frequent mountain masses and rivers or streams interrupting the ridge lines. The valleys vary in width and are primarily used for agriculture. Numerous small villages are located in the valleys. Evergreen and deciduous trees cover the hills and ridges. Slopes are generally steep. With bank preparation, rivers are fordable by most tactical vehicles. The most rugged terrain in the corps area is in the 32d Infantry Division sector (corps left). This sector has generally rough terrain and few roads or trails. The valleys are narrow and run into several dominant high-hill masses. Vehicle trafficability in the valleys depends on soil moisture content. During the spring and summer, irrigation, crop flooding, and rains generally limit vehicles to roads and high ground. The terrain in the 31st Infantry Division (corps right) gradually becomes less severe farther away from the 32d Infantry Division sector.
This sector on the corps right generally has wider valleys, providing better off-road vehicle trafficability, and more roads to support motorized and armored unit attacks. This is the best sector for the enemy to employ armored units. There are several cross corridors over the interdivision boundary between PL RIVET and PL DODGE.
The corps defeats the first enemy attack forward of PL HOE and establishes a hasty defense. The depleted leading enemy divisions establish defensive positions in the vicinity of PL BALL. The corps commander orders the forward divisions to establish a defense on stronger terrain to the rear of PL BLUE. As they pull back, the corps ACR establishes a security zone forward of PL BLUE. The divisions construct barriers and defensive positions in depth from their new FEBA, integrating into those left over from previous operations.
Maneuver
The corps commander intends to defeat the enemy corps' attack forward of PL DODGE with a defense in depth. The army commander exploits success with a counteroffense with a reserve corps. The corps commander's intent is to defeat the enemy forward of brigade rear boundaries--not to retain terrain. Terrain is only a combat multiplier in this defense.
This example now discusses the tactics and techniques for employing the 32d Infantry Division (on the corps left), which will be referred to as the division or infantry division.
The terrain in the division's sector is very rough but gradually decreases in its severity from north to south (left to right). It does not favor using tracked vehicles, except on the right (south) where a few small armored avenues are present. These avenues are primarily trails in narrow valleys. The corps commander has resourced the division with sufficient artillery, engineer, air, and aviation assets to fight an infantry attrition battle in rough terrain. This division is unlikely to get additional corps units or support unless the enemy shifts his main effort.
The division commander's mission analysis confirms the corps' estimate of the situation. His priority mission is to first defeat the expected infiltrating division and block enemy forces attacking in sector along his right boundary. He must prevent them from penetrating and enveloping the adjacent division on the right--the corps' main effort. (See Figure 4-8.) The terrain favors this mission.
The division commander deploys three brigades abreast. This decision was influenced by the strength of the terrain, width of sector given to the supporting effort division, and numerous enemy infantry avenues of approach. These brigades influence and canalize enemy infantry units into EAs where they are destroyed with massed mortars, artillery, CAS, and attack helicopter fires. Infantry maneuver is limited to moving between blocking positions and a few limited counterattacks (counterpenetration). These movements are dictated by unexpected enemy movements (through deep NAIs and DPs) to contain penetrations or to counter his attempts to envelop critical positions or units. After defeating the enemy infantry in sector, the division plans a sequel to clear zone to PL BALL in support of the army counteroffensive.
The corps has additional GS assets but they are positioned to support the main effort, corps deep operations, and reserve. Since the division is the supporting effort, it will not receive additional support until the enemy shifts his main effort into the division sector. The division's task organization is shown at Figure 4-9.
Deep Operations
The MI battalion's LRSD platoon and the attached infantry platoon are deployed for intelligence collection and targeting purposes. The LRSD teams are positioned in the vicinity of PL BALL and beyond. They are positioned at NAIs selected to observe movements and support targeting. Their observations corroborate other surveillance systems for the early confirmation or denial of enemy COAs. Their primary effort is targeting. The 2d brigade infantry platoon (or scout platoon) is attached to the MI battalion to augment the LRSD effort. The division G3 provides capability to this platoon to communicate with the LRSD base section.
Forward of PL BALL, long-range surveillance (LRS) teams are inserted by helicopters accompanying attack helicopter missions. Infiltration is the alternate insertion method, given adequate time. Behind PL BALL, the teams deploy with the aviation brigade's covering forces and then infiltrate to their positions. Target locations (without observer adjustments) are called in via tasked communications to the LRSD base station and then forwarded to the collection, management, and dissemination (CMD) section and FAIO. The division G2 and DIVARTY S2 coordinate deceptive fires and deep operations fires (targeted by other than LRS teams) to hamper the enemy's deduction or perception of deep LRS team-observed fires.
Deception is targeted at the enemy corps and division commanders. The division's defense should appear to be a forward linear defense in sector on a forward of PL HOE. The deception uses the previously established positions on PL HOE and the former reserve positions in the PL RIVET area. The division commander wants the enemy to expand its artillery preparations on the wrong positions and thereby allow counterfire operations to begin early.
One corps cavalry squadron screens forward in front of the division out to PL BALL. The division light cavalry squadron screen is on PL HOE. The corps squadron's priority is in the south where vehicle movement is easiest for both sides. The light cavalry squadron conducts counterreconnaissance and attrits enemy infantry units by aerial or indirect fires. A covering force was not used because the security zone is too shallow; the terrain limits movements and observation; and insufficient forces are available to counter the superior infantry threat in a covering force area.
Obstacles and terrain benefit the brigade fights. Enemy movement and tempo may be easily influenced with sufficient artillery, CAS, and FASCAM. Obstacles emplaced behind the screening force further reinforce the rough terrain and increase the effectiveness of deep fires as the screen withdraws. These fires not only initially achieve attritions but also influence enemy movements.
Combined obstacles and fires produce the necessary attritions and disruption and alter the tempos for enemy regiments and battalions. The enemy's main attack, reserves, and artillery will seek the best avenues. Our fires and obstacles influence them to stay on or change those avenues and then eventually run into our EAs. Fires and obstacles are also planned on the ridge lines above the valleys. They are used to delay and attrit infantry units attempting to infiltrate, bypass, or envelop our defensive positions.
Deep operations fires are initially targeted on enemy division fire support assets, C2 nodes, AD systems, moving infantry formations, and tank units. Moving infantry formations are attacked with massed and timed fires. These infantry formations are moving in the division's deep operations area. The priority for attack is units moving toward our economy of force area, then those moving away from our engagement areas, and finally deeper echelons. The LRSD teams and other real-time intelligence sources provide eyes-on targeting data so that deep fires provide attrition as well as influence movement. Proactive and reactive counterfire operations by the division are critical deep operations. Artillery is the enemy's major combat power asset and the greatest threat to our infantry's freedom of action. Therefore, the G3 manages deep fires to support the maneuver concept. We attack enemy C2 modes when the close fight is begun to degrade his ability to see our COA and counter it. The enemy's C2 resolution to initial tactical defeat in our division sector must come from the enemy corps HQ and above.
Initially, counter the priority is on long-range weapon systems the enemy uses to conduct his counterfire missions. The second priority is to achieve a sustained daily attrition rate on all enemy artillery. The specified rate should achieve a total loss to his artillery. This is necessary for our freedom of action and maneuver in the counteroffensive sequel. Counterfire may be directed at enemy units or targets of opportunity across the front, or concentrated in one area, forcing him to cross level assets. This overall effect decreases his correlation of forces. During the enemy's approach march, we focus counterfire on artillery formations supporting ground attacks into our economy of force sectors, and on the enemy counterfire systems. During our security force fight, priority for reactive and proactive counterfire missions shifts to enemy artillery units supporting the enemy's main attack.
Counterfire is a must. The infantry cannot move from prepared positions to subsequent alternate or supplementary positions while under artillery tire. Freedom of action is possible only when our counterfire negates the enemy's artillery and mortar fire support.
SEAD must begin early as complementary SEAD. Complementary SEAD must decrease the density of AD systems so that our aviation assets are more effective in the close fight. This is critical since the infantry division relies heavily on attack helicopters and air support for deep operations, proactive counterfire, and subsequent close support.
When the enemy main attack enters division EAs, some deep operations are temporarily suspended; however, targeting, intelligence, psychological warfare, and deception are continuous. Most fires are used for massed fire missions into EAs, with emphasis on time on target and JAAT missions. The G3 will order resumption of deep fires (from the main CP) based on targeting and intelligence for the deep operation. The number of deep missions or percent of tires assets shifted is based on the status of the current close operation (from TAC CP), the wargamed synchronization matrix (decision points), and ammunition availability.
The G3 in the main CP synchronizes the deep operation to the close operation and coordinates the transition from future plans (sequels) and contingency plans (branches) to the current operation. The G3 acts within the division commander's intent and the wargamed "decide" phase guidance. The division commander interrupts the G3's fight only when the intent on decide guidance must be changed.
Division deep operations continuously target enemy forces not committed to the close fight. Fires are targeted separately on enemy battalions. These fires disrupt the enemy's tempo, movement, synchronization, fire support, and control.
The G3 coordinates a battle damage assessment collection plan with the G2. Neither the effects nor the success of deep operations can be determined without battle damage assessment. Surveillance (ground and electronic) and aerial reconnaissance are the collection means that must be planned. Battle damage assessment results and deep operations assessments are the first CCIR for branch (reattack, task organization, reposition forces, and counterattack) and sequel (delay, attack, or withdraw) decisions.
The G3 and G2 coordinate the handoff (from corps) of the enemy corps' second echelon, trailing, or reserve divisions as they enter the division deep operations area. The division G3 assesses the status of the division's close operation. The division may have requested the corps to attack those divisions prior to their arrival in the division deep operations area. The corps responds, first, within its intent, vision, and concept of its own operation and, second, by its capabilities and priorities.
In this example, the infantry division is not initially the corps' main effort. Corps support will probably be limited to supporting the corps' overall intent. It will be less responsive to supporting the division's deep fires needs--unless the interests, intents, and time lines are nested.
The G3 must assess the impact of a failed or less than successful deep operation and the introduction of new or unexpected enemy forces into the division sector. He considers the near-term impact on the close operation, future impact on subsequent operations, his deep operations assets' availability and capacity, and the associated time-distance factors.
The G3 may order reattack missions to compensate for previous unsuccessful or less than successful missions. He counters unexpected new enemy units by initiating deep operations targeted on the lead elements of those units to buy time. He then provides his assessment and recommendation to the division commander--continue with the current operation, execute a branch within X hours, or adopt a sequel OPLAN within Y hours.
Security Operations
The security force is division-controlled and executed by the aviation brigade. The available forces include the division cavalry squadron with two attached light infantry companies; one division attack battalion and one OPCON corps attack helicopter battalion; one OPCON corps and two divisional combat aviation companies; and engineer, ADA, GSR, and chemical smoke units. The security force unit's mission is to provide early warning, destroy enemy reconnaissance elements, influence enemy movements into EA SAND and EA ROCK, and attrit the leading enemy units using fires only.
By the time of contact, the enemy's COA should be confirmed. Time for necessary repositioning is gained through the combination of deep operations and disruption or delay caused by attritions inflicted by the security force.
One corps cavalry squadron initially conducts a screen forward of the division under corps control. The majority of this squadron are employed in the southern half of the division sector focused on the corps' interests. This squadron will withdraw quickly because of the shallow depth of the security force area. This corps security force area is between PL BLUE and PL BALL.
The brigades are tasked to maintain contact between themselves and the adjacent divisions. Contact is defined to be at least continuous reconnaissance or surveillance between adjacent units. Without mutually supporting fires or designated security forces, adjacent commanders must coordinate tactical responses to contain or defeat enemy penetrations. The responsibility is left to right and rear to front (for defense in depth) unless modified by mutual agreement between commanders.
The enemy can easily bypass friendly units, which are deployed in depth rather than linearly. Bypassed units can be accepted in the defense in depth; however, the commander accepts them with full knowledge, not by surprise. In a defense in depth, the flank to be secured is difficult for the division commander to perceive, except in terms of maneuver and tempo. The senior commander designates a phase line to be used as a reconnaissance and surveillance line which must be maintained by security operations. The intent is to maintain freedom of movement and minimize surprise envelopments, infiltrations, or penetrations beyond or behind the designated phase line.
The division commander is reasonably certain that any enemy forces crossing the phase line have been seen and reported and or tracked. He can assess the impact or threat to his freedom of action or maneuver with a degree of confidence. Forward of the phase line, the reliability of his assessment decreases. Units forward of the designated phase line are responsible for their own security. They are left forward by design based on the overall operation. The senior commander's concept of operation or timeline concept by design should not be affected if those forward units are bypassed. The phase line is moved rearward as the enemy moves forward in sector until it is on the last delay position or defensive line. Here, its purpose is to prevent surprise enemy penetrations into the division rear area. If necessary, the division commander may establish a security or R&S area behind the brigades with the division cavalry squadron and division reserve blocking positions. The mission could be expanded to a screen mission by requiring the screen force to destroy enemy infiltrators or reconnaissance elements. If properly reinforced, the mission becomes a covering force that contains or destroys small penetrations.
Close Operations
This division commander specifies general blocking positions for the brigades. By doctrine, this is unusual. However, the division commander wants to alter the tempo of the enemy forces, establish the tempo and maneuver of the friendly brigades, establish EAs for massed division fires, and focus the division's effort to support his vision. General battle positions, fortifications or prepared positions, obstacle areas, and engagement zone graphics express his intent and vision for maneuver, synchronization, and conduct of the battle.
Graphics depict general blocking positions and fortification symbols to focus brigade effort. Coordinating instructions in the division OPORD direct the brigades to analyze the METT-T and determine tactically feasible and correct battle positions. General fortification symbols on the overlay focus primary orientation and degree of resistance and also engineer effort. At the division level, the exact trace or length of the fortification symbol does not represent detailed requirements or tasks. It only conveys intent. The blocking position symbols do not specify the size of the force to occupy the position. Again, they only convey intent. The brigades are not required to position the bulk of forces inside the specified blocking position symbol. Brigades must position forces, reinforce the terrain, and construct prepared and fortified positions so that the division commander's intent and vision are satisfied with respect to the enemy. This synchronizes combat effort of brigades to the division maneuver concept, alters tempo, and shapes conditions for the close battle. Synchronization is confirmed during the division commander's backbrief rehearsal with his subordinate commanders. The commander specifies blocking positions only when he believes they are required for expressing a clear intent and concept.
The 2d brigade sector is the key to the concept of operations. The enemy's main attack with infantry units is expected in the 1st and 2d brigade sectors. An enemy supporting effort with some tanks is expected in the 3d brigade area, possibly with forces crossing over the boundary from the adjacent friendly division's sector. The 3d brigade must contain armored penetrations forward of PL BANK and ensure that 2d brigade is not enveloped from the 3d brigade sector.
However, enemy infantry may also use avenues of approach through the rough terrain in division's center into battle positions 20 and 30. Engagement area BETH was specified to counter this possibility. The 1st brigade turns enemy units into the 2d brigade sector (EA SAND). The 2d brigade inflicts heavy attritions on the enemy in EA SAND, turns surviving enemy units into EA DIRT, and avoids being encircled on BP20. The combination of the battalion-sized strongpoint 2 and BP22 denies the enemy's access to the division rear, Strongpoint 2 also stops the enemy from massing and crossing over between EA PILL and EA DIRT. The 2d and 3d brigade defenses protect the division rear as well and contain the enemy's supporting attack against the corps. The 1st brigade secures the division flank and denies any penetration of PL BANK. If the enemy's main effort is in the south, the division will retain BP10 (1st brigade), BP20 and SP2 (2d brigade) and BP32, BP30, SP36, and SP35 (3d brigade). The 3d brigade will provide a battalion as the division reserve.
If the enemy is not successful in the 3d brigade sector, the 2d brigade may leave forces in BP20. Then the 1st and 2d brigades will conduct a true defense in depth. Otherwise, the 2d brigade operation will be a delay to BP22 and SP2.
Because of the 2d brigade's pivotal role, the division commander must approve any battalion-sized decisive engagements in their sector forward of PL BANK. Approval is initially coordinated in the planning backbrief process on a concept or a request basis during the operation.
According to the division plan, the 1st brigade accepts decisive engagement in sector which turns the enemy formations into EA SAND and or EA DIRT. The 1st brigade maintains contact with adjacent division on the left. The 3d brigade must accept decisive engagement until the 2d brigade withdraws from BP20. The division commander decides to defend or withdraw from BP20 based on intelligence collections on the enemy's movements in the vicinity of PL BALL. After the BP20 action, the 3d brigade commander decides when to accept decisive engagement.
The division commander intends to minimize subordinate unit movements. When necessary, they are accomplished primarily by vehicle or helicopter. This conserves soldier strength and builds unit tempo. Specific situations may need combinations of truck, air, and foot movements. Repositioning movements are feasible when envisioned and planned. Detailed planning is required for the sequence of moves, assembly areas, routes, lift assets, number of lifts, disengagement fires, and covering fires.
The defense in depth to defeat enemy forces focuses on enemy unit movements through the defensive sector. The division commander states his vision to influence the enemy movements through the use of infantry operations and deep operations. The division must provide a concept of operations, designated general battle positions, EAs, and obstacle area intents, and then detail what the brigades must do to support the division.
Brigade commanders must still plan their operations to support the commander's intent. The division has not specified the size of forces to occupy division-designated battle positions (BPs) nor have they articulated the BP occupants' sequence. The brigades must also determine when and where they will accept decisive engagement. They must determine how they will contain the enemy forces in the designated EAs and prevent enemy penetration or infiltration through their sectors.
The maneuver concept of the operation allows defensive positions to prepare in depth to counter COAs. This is not possible if the brigades plan their own operations without a division-level maneuver concept or vision. This concept can accommodate a true defense in depth with small units firing from numerous positions onto the avenue or into the EA. These units would be in a high-risk situation against a strong enemy infantry force, which would attack and destroy these dispersed positions. Therefore, the division must maintain some control through a maneuver concept. Targets are developed with the brigades to be attacked by massed division fires. The division controls movements between BPs until the division can accept a decisive engagement. At this point, the brigade commander, by his plan, may have forces deployed in depth over a shallower depth of the sector than in a true defense in depth. The infantry unit does require the maneuver and speed potential afforded by helicopter and trucks plus massed fires in order to break contact and move. The division commander must envision this battle and orchestrate its execution. He must therefore impose his will on his brigades before he can impose his will on the enemy.
Reserve Operations
During the security force operation, the division reserve is a designated infantry battalion. This battalion is preparing a position in BP22 (in the 2d brigade area). Aviation lift assets and DISCOM trucks have been identified and given on-order missions to move the division reserve (-) beginning not later than one hour after notification. The first airlift company should begin movement NLT 30 minutes after notification.
Following the security force operation, the reinforced division cavalry squadron becomes the division reserve after a brief reorganization period. The reserve's mission is to counter enemy penetrations and infiltrations with limited objective counterattacks. The enemy must be contained within the EAs. The priority of employment by sector is 2d brigade, 3d brigade, and 1st brigade, in order.
The reserve will be reconstituted with an attack helicopter battalion and a reorganized engineer company taken from engineers supporting the 1st brigade. The division reserve provides Level III response to threats since a dedicated TCF is not feasible in this example. The rear CP exercises control and planning authority.
Rear Operations
The enemy poses a significant threat to the rear area with special operations elements and infiltrating units. The division rear is organized into mutually supporting base clusters under the control of the rear CP. Rear area units are localized as much as possible in the DSA for security reasons.
The division does not have sufficient forces to have a dedicated TCF. During the battle, the reinforced division MP company responds to Level II rear area missions.
During the security force operation, the designated division reserve, (one infantry battalion), provides to Level III response to threats. After the security force operation, the division cavalry squadron (+) provides Level III response to threats. The division OPORD specifies "be prepared" missions for artillery and attack helicopter support within a specified time period. The response time is a derivative of the movement plan and transportation assets that are provided (organic, attached, or DS) or are available (on order or be prepared GS).
Intelligence
The G3 develops a decision support template based on the chosen COA for close and deep operations. The defending infantry units must be correctly positioned in prepared positions to defeat the larger enemy force. If repositioning is required, it must occur before contact is made on PL RIVET. Decision points on the DST trigger repositioning moves.
Intelligence operations must provide maximum lead time to maneuver commanders by early confirmation or denial of the enemy COA. Priority for intelligence operations then shifts to the critical targeting effort. Our principal defeat mechanism is massed fires on exposed formations. Targeting, therefore, flows from the initial tactical intelligence priority collections.
The division collection plan is synchronized to the corps plan to deconflict competing demands of intelligence and targeting operations. The corps supports the intelligence collection effort. These collections typically involve longer-range assets for which the corps usually has a common collection interest. Targeting for the division is typically detailed, asset-intensive, and focused in the division's deep operations areas. Corps targeting effort is beyond the division's deep operations area. Therefore, corps and division targeting efforts do not generally overlap. The division coordinates a phase line with the corps for handoff so that an intelligence gap is not created. The coordinated handoff of moving and targeted units from corps to division is critical to success.
One infantry platoon has been attached to the MI battalion to increase the LRSD targeting capacity. The platoon reorganizes into five teams: platoon HQ and net control, three squads (-) under the squad leaders, and a provisional team under the platoon sergeant. The platoon leader, with FM and tactical satellite (TACSAT) radio capability, acts as the platoon net control and communicates with the MI battalion's LRSD base station. The platoon sergeant, with a provisional team, acts as an alternate NCS. The three organic squads (-) report via radio to the NCS when deployed.
Both the LRSD and attached infantry platoon teams are positioned to observe NAIs, TAIs, and DPs. They are inserted by helicopter beyond the covering force and then deploy on foot. Those teams located short of, or in, the covering force unit area are inserted by vehicle and then deploy on foot. The primary purpose for all teams is to support the targeting process.
The division MI battalion's collection assets are task-organized as company teams. These three teams are retained in GS under the control of company A HQ. One team is located in each brigade area and an intelligence liaison officer is provided to each maneuver brigade HQ. The brigade commander can task the team or MI battalion with information requests directly through the liaison officer. Company A HQ locates in the 2d brigade area. The company commander coordinates locations for collectors directly with the brigades or with the security force brigade HQ.
The I&S company (-) locates with the division EPW collection compound. It is GS to the division. Each of its ground surveillance radar (GSR) squads is attached to a maneuver brigade. The platoon HQ with one remaining GSR squad is DS to the division security force. On order, it is attached to the division MP company. In the forward area, the GSRs are used for early warning. In the rear, the GSRs are used for rear area security and surveillance operations.
Initially, PIR are to confirm or deny the enemy COA. Specifically, the commander wants to know--
- Time of the enemy attack and the avenues of approach.
- Location of the enemy main attack (now expected on the right flank).
- Location of organic enemy tank battalions.
- Location of the mechanized brigade.
- Location of the expected infantry division infiltration into the division area.
- Location of corps and division supporting artillery units.
Targeting priorities are on division-level enemy artillery units. Priority is to MRLs and corps and division-level artillery groupings, nodes, AD systems, moving infantry battalions on avenue A, moving infantry battalions on avenue C, and then tank units in the 3d brigade sector. On order, targeting priority shifts to infantry battalions on avenues of approach B1 and B2.
Fire Support
The corps has task-organized one FA brigade to reinforce the infantry division. The corps delegates authority to the division commander to subassign missions. The FA brigade has three towed 155-millimeter FA battalions, one 155-millimeter SP FA battalion, and one MLRS FA battalion.
Initially, the aviation brigade executes the division's security force fight out to PL HOE. The corps FA brigade is initially DS to the aviation brigade for the security mission, with on order mission to reinforce DIVARTY. Three corps towed 155-millimeter FA battalions and the DIVARTY towed 155-millimeter battery are attached to the FA brigade for the mission. All four units are located forward in the brigade sectors to facilitate their subsequent reinforcing missions. (See Figure 4-10.)
DIVARTY HQ initially controls the corps MLRS battalion, the 155 SP FA battalion, and the target acquisition detachment. DIVARTY controls deep operations and counterfire operations. On order, massed fire and time-on-target missions on massed enemy infantry units are the frost priority. The DS FA battalions are left with the maneuver brigades to fire on enemy infiltrations or penetrations.
The divisional cavalry squadron does not have organic fire support teams (FISTS) for the security force fight. However, the two attached infantry companies both have FISTS. The divisional cavalry squadron employs DIVARTY combat operation laser teams (COLTS) during the security force operation.
COLTs are important since each enemy infantry division has one organic tank battalion. The FA brigade specifies support relationships and Quickfire channels for all battalion HQ, troops, and companies.
The corps withdraws the ACR, leaving the division-controlled aviation brigade security force between the BHL and PL BLUE. The divisional cavalry squadron remains forward until withdrawn. The FA brigade supports it from the MBA.
After the cavalry squadron withdraws, the division fights in depth with three brigades abreast. All three are supported by their habitual towed 105-millimeter FA battalions. The 1st and 2d brigade DS battalions are each reinforced by one 155-millimeter towed FA battalion. The 3d brigade DS artillery battalion is reinforced by the divisional towed 155-millimeter FA battery. The DIVARTY is GS to the division with first priority to counterfire and massed fires on order. The DIVARTY controls the MLRS battalion and the target acquisition platoon. The FA brigade provides GS tires with one 155 SP battalion and one towed 155-millimeter battalion. These battalions support the division's deep operations, counterfire, and SEAD, as well as the maneuver brigades.
Initially, PL BALL is the FSCL. When the corps security force withdraws, a CFL is established on PL RED. From that point on, CFLs and FSCLs are moved using successive phase lines. To the rear of PL RIVET, infantry units are or may be deployed in depth. Brigade commanders establish CFLs for their sectors to the rear of PL RIVET, which are consolidated at the TAC and approved by the commander.
The division commander's defeat mechanism is to use massed fires to destroy enemy units in EAs. Infantry units in prepared positions, close fires, and deep operations must canalize the enemy into those EAs. The DIVARTY coordinates the positioning of all fire assets so that massed fires and time-on-target missions are possible across the division front, with priority to the EAs. Those EAs designated support the division concept. Maneuver brigade commanders may coordinate their own EAs through their FSOs to support their maneuver concept.
Mobility and Survivability
The infantry division does not have a division engineer brigade and must rely on the corps for adequate engineer support. The corps engineer brigade has four engineer groups which support the corps rear and the three infantry divisions. The infantry division's engineer group is task-organized with three combat engineer battalions (wheeled), three CS equipment companies, and one engineer bridge company. The division has the authority to subassign missions.
During the wargaming process, the division commander, G3, G2, and division engineer developed a maneuver with a supporting mobility, countermobility, survivability concept. The division commander has specified obstacle areas with his obstacle intent for each area. These areas are a graphic expression of the commander's vision to influence enemy maneuver and tempo. Engineer effort, coordination, and CSS requirements are guided by this vision. It is a commander's maneuver vision, not an engineer's obstacle plan. The subordinate commanders at brigades do the same. They are free to plan tactical obstacles and belts inside the division's obstacle zone. Protective obstacles can be planned outside of obstacle control measures. However, the brigades must accomplish the division commander's overall maneuver, tempo, and countermobility intent as their frost priority. The total effect of all obstacles in the division obstacle areas must accomplish the division's intended purpose. The brigade and battalion commanders' roles are to translate division maneuver-based obstacle areas into tactically correct and feasible obstacles. (See Figure 4-11.) Obstacle areas and restricted areas were further discussed in this chapter's Defense in Sector: Terrain Retention. Obstacles are planned IAW FM 90-7.
The division commander wishes to canalize the expected enemy infantry division attack into EA SAND and then EA DIRT on avenue of approach A. Enemy infantry on avenue B is to be contained at EA BETH and then canalized into EA DIRT. Enemy flank units from the enemy corps main attack in the adjacent division sector may enter the 3d brigade sector on avenue C. These units must be contained in EA ROCK, if possible. If not, they must be canalized into EA PILL and destroyed, (See Figure 4-10.)
The division inherited obstacles from previous combat operations between PL MOE and PL BALL. This area is now the current division and corps security areas. Corps and division engineers coordinate the work in the security areas behind the security forces to support the maneuver plan. Corps and division engineers task and allocate the engineer work.
Obstacle areas A, E, B, C, D, and G were assumed by the division from other divisions which had previously fought on the terrain. Engineers supporting the security force reinforced obstacles in areas A, B, C, and D. Obstacle area E was modified to a turning obstacle zone. Obstacle area G was modified and reinforced to a disruption obstacle zone.
The security force also inherited some minefield, tank ditches, obstacles, and bridge demolitions. These obstacles are controlled individually since they do not conform to any area, zone, belt, or group. If they interfere with operations or present a threat to friendly units, they are cleared or reduced. They are marked and left in place if they are not a significant hazard or if insufficient engineer assets are available. They are treated as targets or nuisance obstacles.
The division specifies lanes and gaps through obstacle areas to support activities. In this case, division specifies lanes and gaps to support the covering force's withdrawal, with the covering force HQ coordinating the details. Brigades controlling the obstacle areas with the designated lanes or gaps must prepare, mark, and then close them. The division commander reserves execution authority to close them until the covering force withdraws. However, all brigades may close lanes or gaps to prevent enemy capture.
The division engineer work line (EWL) is PL BANK. The corps EWL is PL DODGE except that corps will repair and maintain all corps MSRs forward of PL DODGE to the committed divisions' DSAs.
Engineer priority of effort is to countermobility, survivability, and mobility, and then to sustainment engineering. Priority of support is 1st, 2d, and 3d brigades; covering force; DISCOM; and DIVARTY.
Following the covering force fight, the corps wheeled engineer company is attached to the corps GS wheeled battalion in the division rear. This battalion provides engineer C2 for all engineer work behind the EWL. It controls one wheeled company (after the covering force fight), two combat support equipment (CSE) companies (-), and one bridge company. The one wheeled company provides situational obstacle capability and the ability to reinforce engineers with the reserve or maneuver brigades. The reserve battalion is supported by one divisional engineer company. The reserve is positioned for immediate employment by helicopter or truck. The engineer unit provides gap-crossing capability.
One engineer battalion supports each of the three maneuver brigades. The division engineer battalion (-) supports the 1st brigade with one divisional company, one corps wheeled company, and one CSE platoon. The battalion HQ (-), under the control of the executive officer, coordinates all engineer activities in the brigade sector. The second corps wheeled engineer battalion, reinforced by one attached wheeled company and one divisional engineer company, supports the 3d brigade. Division authorizes 3d brigade to convert one engineer company to infantry for use in either SP35 or SP36. Corps approves converting one corps engineer company to infantry. The divisional engineer battalion commander remains the division engineer. He reinforces the ADE section in the main CP and controls engineer operations through the ADE, TAC CP engineer, and rear area GS corps engineer battalion HQ.
Division delegates authority to emplace FASCAM in turning, fixing, disrupting, and blocking obstacle zones to the brigade commanders as well as authority to execute planned FASCAM on all lanes and gaps. The division commander reserves, however, execution authority on division-specified lanes and gaps. The division G3 approves planned targets or situational obstacles using FASCAM outside of zones to protect flanks and slow enemy forward movements on the battlefield. FASCAM is primarily planned to develop targets for other fires to exploit.
Air Defense Artillery
The USAF maintains air superiority over the theater in this example. The enemy air force, although striving for localized air superiority above its ground attacks, has had limited success. The enemy's most effective air weapons have been attack helicopters to support attacks at the FLOT. Therefore, the enemy air threat is low in the division rear area but constitutes a significant threat to forward units.
The major air avenue threats in the division sector approach the FLOT frontally, following the valleys. These are all attack helicopter routes. The major high-performance aircraft air avenue parallels the interdivision boundary in the more open terrain area.
Initially, the covering force is supported by battery B (-), which is OPCON, and one attached Vulcan/Stinger platoon from battery A.
The attached platoon stays with the divisional cavalry squadron as the division reserve, following the covering force fight. The OPCON corps light cavalry squadron is supported by an organic Vulcan/Stinger platoon from the corps light cavalry regiment. When the covering force withdraws, battery B (V/S) (-) is placed in DS of 2d brigade. The battery B HQ assumes control of its 1st platoon which was left in support of the 2d brigade.
The 3d brigade is supported by battery C (V/S) in direct support. It orients on the attack helicopter and high-performance aircraft avenues. This battery also supports the withdrawal of the corps light cavalry squadron from the CFA.
The 1st brigade is supported by battery A (V/S) (-) because it principally has only one attack helicopter air avenue entering directly into its sector. Battery A must also protect on the north side of EA DIRT against air avenues originating in the 2d brigade sector.
ADA protection for the remainder of the division relies upon passive AD measures, success of the USAF counterair campaign, and incidental coverage from the corps ADA weapons systems. Critical CSS and aviation assets with low recuperability are located in the DSA under the potential corps ADA coverage.
The towed Vulcan and Stinger systems are located forward in the brigade areas. As the first priority, they must counter the attack helicopter threat; second, the high-performance aircraft. Towed Vulcans are positioned to provide effective ground fire support to infantry units while moving. They are also positioned to add to the volume of massed fires in the EAs. The division ADA defense plan places great reliance upon the USAF counterair operations.
The terrain forces the aircraft down parallel valleys into the FLOT or above the terrain where they will be easy to detect and engage. The USAF will counter high-performance aircraft. The division ADA systems' priority is attack helicopter defense.
All air defense assets, except for the covering force and reserve ADA units, are placed in DS. The ADA battalion HQ advises the division commander on AD systems employment, support relationships, and air threat status. This HQ is responsible for the division's early warning system.
Priority of support is to the 2d, 3d, and 1st brigades, and then the reserve. The covering force brigade is the first priority until the division commander withdraws it.
Combat Service Support
In this defense in depth, the CSS units are located well to the rear of their supported units' sector. Noncritical elements may be moved back from the BSAs to the DSA for rear area security purposes. Positioning of units is dictated first by the support needed to the immediate fight. The second consideration is the enemy infiltration threat. Wherever the units support from, they must cluster together for security purposes. Throughput distribution is desirable.
The FSBs are located on the brigade rear boundary since the last defensive positions are in the vicinity of PL BANK. The 3d brigade's FSBs BSA is partially located in the division rear area. Control of the area is exercised by the 3rd brigade FSB commander. (See Figure 4-12.)
The defense in depth concept may leave infantry units in contact throughout the depth of the sector. This makes CSS actions more difficult to execute because of the distances, multiple unit locations, and enemy actions. The brigades' concepts of operations are fully coordinated with the supporting FSB. The DISCOM and G4 are informed of requirements and shortfalls, Class I, IV, V, and VIII stocks are prepositioned in known-use locations before the covering force withdraws. Stocks are placed in all positions where infantry decisive engagements are envisioned, such as BPs and SPs along PL BANK. Artillery munitions are prepositioned to support massed fire missions into EAs.
Resupply by vehicle is difficult due to the limited road network and poor-quality roads. Resupply by a prepackaged push system delivered by helicopter may be the norm. Class VIII stocks are maintained in battalion trains. Landing zones are established for each BSA and for battalion trains. These LZs also support aeromedical evacuation.
Medical evacuation is difficult due to the road conditions. Helicopters evacuate casualties to supporting corps mobile Army surgical hospitals in the division rear and evacuation hospitals (CS hospitals) in the corps rear area. These are located along corps MSRs in division rear with dedicated LZs. Ground evacuation is planned for bad weather periods.
Corps support group units are located in the corps support area near the DSA. These units provide critical heavy maintenance support to the supporting corps artillery and engineer units. Corps maintenance support teams are formed and moved forward to BSAs for more responsive support. The forward corps support battalion (CSB) provides reinforcing support to MSBs and FSBs to enable them to support the corps organizations supported in the BSA and DSA.
Movements in the division rear are strictly controlled by the division MCO. The limited road network must be managed for efficiency in efficiency actions and unit movements. If necessary, division MSRs are extended forward into the brigade sectors and controlled by the division.
Intratheater airlift (C130 aircraft) and corps aviation support (CH-47 helicopter) are planned to maintain steady CSS flows to relieve the limited road network. The division G4 and DISCOM commander must plan current and future C130 airfields and helicopter LZs. These critical engineer tasks require considerable planning, materials, and equipment.
Nuclear, Biological, and Chemical
One corps smoke and decontamination company is attached to the light division. Because the enemy has already used artillery and rocket delivered chemical munitions, the NBC priority is chemical decontamination. Smoke requirements are satisfied by using artillery or mortar smoke munitions or smoke pots.
Four dual-purpose platoons are available in the division sector. One dual-support platoon is positioned in each infantry brigade sector. The company HQ and the fourth decontamination platoon are positioned near the DSA. Each provides general support on a geographical basis. Decontamination sites are selected to the rear of the brigade sectors because of the defense in depth. These positions are relatively secure behind PL BANK where the enemy will be held. Alternate positions are selected to initially support the withdrawal of any contaminated covering force units. These positions are also true alternate positions in case one of the primary sites becomes unusable.
Priority of decon support is, in order, artillery units, CSS units, combat zone (CZ) facilities, engineer equipment, and infantry battalions. No decontamination support is provided to the covering force. On order, the first priority for decontamination is the reserve battalion.
Command and Control
The light division TAC CP locates in the 2d brigade sector near the brigade CP. This brigade is the division's main effort following the security force units' withdrawal. From that location, the TAC CP can see the critical battle unfold in the CFA into EA SAND. It is also well situated to control the battle if the enemy's main effort comes into EA BETH or EA ROCK. The location is driven by the need to control changes, not just to be near the main effort. The TAC CP increases its security by locating near brigade units.
The main CP faces very little air threat, but artillery is a danger. Therefore, it is located beyond artillery range in the division rear. It locates itself near communications nodes and the reserve unit to facilitate planning and executing branches. The main CP derives security by locating near reserve units. Military police will not be used for security.
The main CP synchronizes deep operations to the close operation to support the commander's vision. It also updates and executes sequel and branch operations plans to the current operation so that the two can meet at some point in time and space. This is called transition operations. The planning and control of collateral operations is also critical for cross-FLOT attacks, LRSD operations, intelligence collection, counterfire, SEAD, and movements. The G3 in the main CP is the principal staff officer for planning and synchronizing collateral and transition operations.
The rear CP collocates with the DISCOM HQ in the DSA. Its security is provided by clustering with DISCOM units. The rear CP plans and controls terrain management, rear area security, sustainment, and movements control. Movements control and sustainment operations are shared actions with the G1, G4, and DISCOM. Terrain management and rear area security are the primary roles for the rear G2 and G3. These are critical in this example since the terrain is rough and the road network is poor and limited. Firm and proactive control is required.
MP Operations
The infantry division is the corps' supporting effort and provides only one corps MP GS platoon to the division. However, the corps MPs provide battlefield circulation control on corps-designated MSRs to the DSA and evacuate EPWs from the division EPW collection point.
The division band operates the EPW collection point in the division rear area. Band personnel are supervised by the MP company HQ. The attached infantry platoon is located with the MP company HQ and is truck-mounted. The infantry platoon augments the MP company's combat power response to Level II rear area threats and conducts other rear area security operations. After the division security force withdraws, the ground surveillance radar (GSR) platoon (-) supports the MP company rear security operations with one GSR squad. The four MP platoons, three division and one corps, are assigned area responsibilities. They are GS to the division and controlled by the MP company HQ.
The first MP platoon's area is the 1st brigade sector extended into the division rear area to PL JOE. The second platoon's area is the 2d brigade's sector extended back to PL JOE. The third platoon's area is the 3d brigade's sector extended back to the division rear boundary. The fourth platoon's area is in the division rear area bounded by the division rear boundary, division and corps left boundary, PL JOE, and PL PARIS.
The priorities for the four MP platoons are battlefield circulation control, rear area security, EPW operations, and then law and order operations. Corps MPs provide battlefield circulation control on corps-designated MSRs. Division-controlled MPs provide traffic circulation and control on division and brigade MSRs or supply routes (SRs) forward to battalion trains areas. Rear area security missions provide support, in order of priority, to MLR units, Class V points and convoys, attached helicopter units, lift helicopter units, and other CSS units. Division MPs will escort EPW movements only from brigade collection points to the division collection point.
The MP assets are kept under division control because the number of MP units is inadequate for the mission tasks. The division must intensely manage the limited road network as well as counter an enemy rear area threat. The MP units perform security operations to intercept or discover enemy special operations forces or small unit infiltration. The attached infantry platoon provides added combat power for this mission.
Mobile defense orients on destruction of the enemy by using a combination of fire and 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 that part of the force dedicated to the defense. 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 the counterattack of a larger, mobile strike force. The mobile defense sets up large scale counterattacks that allow the defender to destroy enemy forces, gain and retain the initiative, transition to the offense, and move into exploitation and pursuit operations.
In this example, a third world country is being threatened by invasion from a neighboring country. The invasion appears to be imminent. Diplomatic efforts to resolve a long-term border dispute are at a stalemate. The hostile country has started national mobilization and continues to escalate armed forces along the adjoining border.
The threatened country has formally requested that the US military intervene 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 Authorities (NCA) has directed the deployment of a JTF into the crisis area as a show of force.
The JTF's maneuver forces consist of a light division with an attached armored brigade. The infantry division, executing its emergency deployment sequence, begins air deployment into the host country within hours of notification. The attached armored brigade closed into the division lodgment area within days of notification. This deployment was accomplished by a combination of strategic sea and air lift. The lodgment is located in the vicinity of the country's 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 host country forces.
Intercepted high-level message traffic reveals the hostile country is planning to commence its invasion when it completes mobilization. The invasion force's mission is to rapidly push as far forward into the disputed area as possible and secure selected objectives within the disputed area. On securing selected objectives, the government intends to appeal quickly to the United Nations (UN) for a cease-fire and negotiate a more favorable border settlement during UN negotiations. 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 country within the past four years. Its ground forces comprise four active infantry divisions, a border defense force, and one separate tank regiment which has recently been upgraded with T-72s. Each infantry division comprises two infantry regiments and one motorized rifle regiment with supporting artillery both at the regimental and divisional levels. The air force (fixed wing) is limited at best and should not present any significant obstacle to the deployed JTF forces. However hostile forces have enough rotary-winged capability to lift two battalion-sized units in a single lift.
The host country has three infantry divisions and an internal border security force available. Of the three divisions, two are active and the third, an auxiliary division, is manned with reservists during national emergencies. Limited armored vehicles are found in the border security forces only. The country's air force is comparable to the hostile air force, offering limited offensive capabilities.
Anticipating an invasion, the host nation has deployed both of its active divisions along their threatened border to reinforce their border security forces. Increasing incidents of border violations by the hostile ground forces have resulted in increasing engagements. These border violations appear to be probing missions to identify unit locations and force density along potential invasion routes.
The border terrain between the two countries is mountainous. One major valley system has natural mobility corridors which support motorized vehicles. Vegetation varies from sparse in the low, open areas to double and triple canopied in jungle and mountainous areas.
The JTF commander intends to defeat the invasion force by establishing his AO to the rear of the existing host nation's border defensive positions along the main invasion corridor. He intends for the host nation to establish initial contact with the lead invasion forces before committing JTF ground forces in direct contact. This action will demonstrate the invading country's aggression and the host county's resolve against the invading country. Once the invasion commences, the JTF commander intends to quickly develop the situation to contain the main invasion force and destroy the enemy units with swift, overpowering forces. Upon halting invasion forces, JTF elements will quickly transition to the offense, forcing the enemy to withdraw and reestablish the recognized border within the JTF AO. Quick success against enemy invasion forces will defeat the enemy's national will to continue aggression. During this operation, the airport activities within the lodgment area must not be interrupted. Once the border is reestablished and hostilities have ceased, the JTF will posture to redeploy rapidly.
Maneuver
The division commander establishes a mobile defense along the main invasion corridor behind the host country's border defensive positions, to destroy the main invasion force that penetrates border positions. The division delays and neutralizes the invasion forces through the depth of the division's sector. Two brigades positioned forward defend in sector to delay advancing forces, prevent infiltration within the division's sector, and attrit the enemy. This causes the enemy to commit his reserve forces early and to overextend his main attack. (See Figure 4-13, and Figure 4-14.)
The 3d brigade establishes a blocking position to the rear of the forward brigades that contains those forces that penetrate the defending brigades. This fixes the enemy forces, creating the opportunity for the armored strike force to maneuver to destroy the contained forces. The lodgment security is vital to the JTF operation and is secured by a two-battalion force with augmentation from host forces. The desired end state is the destruction of the attaching enemy's invasion forces and a quick transition to the offense, forcing withdrawal of the hostile country and reestablishment of the international border.
Deep operations for the division initially are limited in depth due to the JTF-imposed "no cross-border operations" restriction. Close coordination with in-place host country border forces is established to designate EAs forward of the division. Deep fires neutralize enemy artillery support, decreasing follow-on forces' operational tempo. This action provides time for the defending brigades to concentrate their combat power without interference by follow-on reinforcements. The aviation brigade disrupts and destroys enemy follow-on motorized and armored forces supporting the forward defending brigades. Deep fires and obstacles provide time and help seal off the contained enemy force, thus supporting strike force attacks.
The division cavalry squadron screens forward of the two defending brigades, establishing contact with the host country's border security forces forward of the division's sector. The cavalry establishes contact with those advancing invasion forces that penetrate the border security and maintain contact to provide early warning for the lead brigades. As the enemy approaches the division's sector, deep fires are committed to disrupt, attrit, and alter the tempo of the lead regiments. Maintaining contact with the enemy, the cavalry delays to the battle handoff line, moves through the defending brigades, and establishes rear flank screens. These screens are positioned along both division flanks behind the forward brigade sectors to detect infiltrating enemy forces that threaten brigade to rapidly attack and destroy enemy the lodgment area.
The division establishes a mobile defense with two infantry brigades defending in sector. The third infantry brigade establishes blocking positions to the rear of the two delaying brigade sectors to contain penetrating enemy forces. The mobile defense strike force, consisting of the armored brigade, locates behind the blocking forces in designated objective areas forward of the blocking positions. Two infantry battalions provide lodgment security during the operation.
Designated EAs within the brigades' defensive sectors facilitate massing of combat power during the delay to attrit the enemy. The 1st and 2d brigades establish mutually supporting positions constructed in depth in their respective sectors to detect and impede enemy movement. Defensive positions and integrated obstacles create EAs, allowing massing of available artillery and mortar fires. Available CAS and attack helicopters augment supporting fires. The restrictive terrain and emplaced obstacles limit enemy armored forces to infantry fire support. The 3d brigade contains penetrating forces by occupying blocking positions to the rear of the two forward brigades and sealing off the division sector. This causes the enemy to focus and concentrate his forces on 3d brigade's blocking positions. As the enemy attempts to penetrate the blocking positions, his flanks become exposed and vulnerable for counterattack. At this moment, the armored brigade conducts a swift counterattack into the enemy's flank, destroying the forces forward of the blocking positions in designated objective areas.
Lodgment security provided by the two infantry battalions from the 2d and 3d brigades prevents interruption of the airfield and lodgment support activities from infiltrating forces. One company within the lodgment is designated as the division reserve.
Upon 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.
Fire Support
Fire support assets mass fires to disrupt and destroy moving enemy units in engagement areas. Infantry units in prepared positions close fires, and deep operations canalize the enemy into those designated EAs. The DIVARTY coordinates the positioning of all fire assets so that massed fires and time-on-target missions are possible across the division front.
Intelligence
Intelligence operations provide early warning and lead time for maneuver forces by confirming or denying enemy COAs, The LRSD teams are positioned to observe NAIs, TAIs, and DPs. The GSR teams are attached for early warning both with forward maneuver brigades and to units providing lodgement security. The division's developed collection plan supports the developed PIR which is critical to the targeting process and the enemy's destruction.
Mobility and Survivability
The division commander specifies general obstacle zones to fix the enemy to increase attritions, cause enemy supporting artillery to deploy, and 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. One fixing zone is designated forward of the 3d brigade to assist in the enemy's containment. The obstacle plan facilitates delaying the enemy forces and develops the conditions that cause the enemy to expose his flanks, providing opportunity for strike force attacks.
Air Defense
The division is operating in a low air threat environment. Stinger teams are attached to each maneuver brigade and the battalion (-) is located within the lodgment area. These assets provide integrated ADA coverage against potential enemy heliborne operations.
Command and Control
Division rear and main CPs locate within the lodgment area. The rear CP controls the divisional activities within the lodgment to include security. The TAC CP locates forward in the division sector behind the blocking brigade. This forward positioning facilitates synchronizing the delay of the two forward brigades and the control of the armored brigade when committed.
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--has reached a culminating point. 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.
Normally a force defends to develop favorable conditions for an attack or to act as economy of force in one area to mass overwhelming offensive combat power in another area. 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 are required to defend, they have two basic options. One is to commit forces and push forward to claim enough ground for a security and or covering force area (that is, beyond the majority of enemy artillery range fans). The second option is to fall back to defensible terrain to establish a security and or covering force 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. (See Figure 4-15.)
Unfortunately, the first option results in loss of additional personnel and equipment and the expenditure of more resources. The security area often lacks depth. Additionally, 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 the better option. Commanders pull back the bulk of their forces to defensible terrain and 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 (the FLOT) remains along the line of contact. The depth of the security and or covering force area is based on METT-T and the operational plan.
|
NEWSLETTER
|
| Join the GlobalSecurity.org mailing list |
|
|
|
