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Fire support for defensive operations can be described in terms of a defensive framework presented in FM 100-15. This framework shows corps and divisions using five complementary elements:

  • Deep operations in the area well beyond the FLOT.

  • Security force operations forward and to the flanks of the defending force.

  • Defensive operations in the main battle area.

  • Reserve operations in support of the main defensive effort.

  • Rear operations to retain freedom of action in the rear area.



Success in the defense depends on the careful planning and execution, as required, of fire support simultaneously in deep, close, and rear operations. Each of the five elements of the defensive framework must be considered when determining fire support requirements.

Basic Tasks

As in the offense, corps and division commanders normally ensure adequate fire support for defensive operations by retaining some assets and allocating others to subordinate units. The four basic tasks of fire support provide the guiding principles:

  • Support forces in contact.

  • Support all aspects of the battle plan.

  • Synchronize fire support.

  • Support and sustain fire support.

Support Forces in Contact

Supporting forces in contact usually means providing support for close operations. If done correctly, this task ensures the survivability of friendly forces and the freedom of maneuver. The various fire support assets support forces in contact in various time-tested roles and missions. The field artillery supports forces in contact in the defense by performing its traditional roles of close support, counterfire, and interdiction. The Air Force operations of CAS and SEAD are specifically intended to support forces in contact, although BAI normally directly affects ground maneuver forces.

Support the Battle Plan

Supporting the force commander's battle plan means retaining sufficient assets for any possible contingency. Fire support assets for the rear and deep operations must be identified. Doing this task gives the force commander the means to attack high-payoff targets whose destruction, neutralization, or suppression is necessary for overall mission success. The vagueness of the initial situation in the defense dictates that the force commander maintains more centralized control of his fire support. This is done at first by keeping more assets under his immediate control or by assigning FA units tactical missions that retain fire planning, priority of fires, and position authority at higher levels. This ensures responsiveness by those units in massing and shifting of fires.

Synchronize Fire Support

The synchronization of fire support at corps and division is essentially a command function. The FSCOORD is responsible for helping the commander integrate all fire support with the appropriate battlefield operating systems. A fire support synchronization methodology is found in the decide-detect-deliver approach to targeting and battle management. The successful use of this methodology enables the commander to attack the right target with the best weapon at the right time. Thus, the force commander can take the initiative in selecting, locating, and attacking high-payoff targets.

Support and Sustain

Fire support for defensive operations must be sustained through all phases of the operation. Fire support systems must be survivable without degradation of availability.

Attack and Acquisition Systems

Specific fire support attack and acquisition systems are allocated through the normal practices such as field artillery organization for combat. Assets will be allocated to--

  • Provide deep fires to disrupt, delay, and destroy enemy follow-on forces before they can engage friendly forces.

  • Provide counterfire to destroy, neutralize, or suppress the enemy's indirect-fire weapons.

  • Provide SEAD to suppress enemy air defense weapons immediately before and during flight by friendly aircraft within the area of operations.

  • Disorganize, delay, and disrupt critical enemy elements before the attack.

  • Use both lethal and nonlethal attack means to apply constant pressure to the enemy's command and control structure.

  • Acquire and attack high-payoff targets throughout the battlefield.

  • Provide fire support synchronized with maneuver and command and control countermeasures (C2CM) in the conduct of deep operations.

  • Retain centralized control of fire support resources in order to concentrate fire at the decisive place and time.

  • Provide fires to support counterattacks.

Nuclear Weapons

The allocation of nuclear fires is discussed in detail in FM 100-30. The table below summarizes the roles of nuclear weapons in defensive operations.



Deep operations begin before the enemy closes with the corps or division and continue throughout the battle. Deep operations are used to effect closure times of follow-on elements and to create windows of opportunity for destructive actions against them. A successful deep operation may cause the enemy commander to change his attack plan because it disrupts his flow of echelons as they move toward the FLOT.


Fire support assets for deep operations are allocated by determining the friendly area of greatest vulnerability and predicting where the enemy will conduct his main attack. Specific considerations include the following:

  • The provision of adequate fire support to achieve operational objectives.

  • The destruction of high-payoff targets in enemy follow-on forces.

  • The delivery of SEAD to support tactical air.

  • The potential use of Army aviation as a means of providing deep fires.

  • The use of AFSOs to facilitate fire support coordination and execution during operations.

  • The use of chemical weapons to delay enemy follow-on forces, disrupt C2, and deny critical facilities and assets (when use of these weapons has been approved).

  • The use of nuclear fires to destroy enemy follow-on forces, C2 facilities, and other high-value targets such as surface-to- surface missiles (when use of these weapons has been approved by proper authority).


The decide-detect-deliver targeting methodology is used to plan and execute fire support for deep operations in a defensive situation just as it is used for the offense. (Refer to Appendix B and FM 6-20-10.)



Within the AirLand Battle defensive framework, security forces perform one of two functions: screening or covering force operations.

Screening force operations for the offense and defense are similar and require the same fire support considerations as discussed in Chapter 4.

Covering force operations in the defense differ from those in the offense in that an enemy attack is expected. Corps and division commanders plan to use the advantages of the defender to defeat the enemy. To exploit these advantages, the covering force must provide the force commander with a developed tactical situation that allows the MBA forces to establish and execute a successful defense. Specifically, the covering force occupies a sector far enough forward of the FEBA to--

  • Protect the MBA units from surprise.

  • Allow the MBA forces time to prepare defensive positions.

  • Prevent delivery of enemy medium-range artillery fires against MBA units.

  • Deceive the enemy as to the location of the main defensive positions.

  • Defeat a specified-size force or exact a specified percentage of damage to first-echelon forces.

The size and composition of the covering force and the covering force area depend on the mission, enemy, terrain, and available forces. Generally, a forward defensive covering force area should be deep enough to force the enemy to reposition his artillery and air defense forces before he attacks.

The level of command for controlling covering forces depends on the width and depth of the area, communications capabilities, available control headquarters, and the number of units in the covering force. Normally, corps and divisions control their own covering force operations. MBA brigade control of covering forces is less desirable. It takes away assets from the MBA, is difficult to control, and complicates reporting.

Fire Support Tasks

Fire support tasks for security forces are as follows:

  • Engage the enemy early to strip away his reconnaissance elements. Specifically, these recon elements must not infiltrate and slip through the covering force. Early fires also help force the enemy to deploy his attack formations.

  • Assist maneuver in moving and disengaging.

  • Provide SEAD to allow attack helicopters and Air Force aircraft to attack. Destroy air defense radars located by EW.

  • Engage engineer mobility detachments to reduce the enemy's engineer mine-clearing capability before he arrives in the MBA.

  • Mass fires that will delay, disrupt, or limit the enemy's advance.

  • Integrate fire and obstacle plans, and ensure obstacles are covered by direct observation.

Allocation of Fire Support

Normally, security forces operate at consider-able distances from their main force and have only minimum maneuver combat power. Additional combat power must be provided to security forces in general and to covering forces in particular, This is done through decentralization of fire support assets. Decentralized fire support provides the responsive firepower needed to--

  • Make up for the lack of maneuver in relation to the large covering force area.

  • Cause the enemy to deploy, thinking he has made contact with the MBA forces.

The degree of decentralization depends largely on the amount of fire support available. Consider assigning--

  • One DS artillery battalion for each battalion-size maneuver element in the covering force.

  • Nonstandard tactical missions to MBA artillery units to make them responsive to the covering force artillery headquarters.

  • The preponderance of other fire support assets to the covering force. For example, UAV, CAS, EW, AFSOs, and TACAIR recon assets must be responsive to the covering force.

Considerations for allocating field artillery support to the covering force in the defense are similar to those in the offense as discussed in Chapter 4. Specifically, three factors must be considered: attachment, representative caliber, and mobility of fire support. At times, all of these considerations cannot be met because of the availability of types or caliber of weapon systems. Then, planners must weigh the factors of METT-T against the overall goals of the maneuver commander's intent.


Covering forces may operate at great distances from the MBA forces. Therefore, it may be very difficult to provide adequate support by only assigning a tactical mission. Problems of command and control may dictate a change to the normal command relationship. This is particularly true when covering forces are spread across a wide frontage or throughout a deep zone. The method of attachment depends on the control of the covering force. If the covering force is being controlled by the MBA headquarters, attachment of FA forces is not necessary. Normally, this is not the case and the covering force has a controlling headquarters of its own. Likewise, a covering force artillery headquarters may be designated. This is often done by attaching an FA brigade to the covering force. The FA brigade headquarters then becomes the force artillery headquarters, and the FA brigade commander is the FSCOORD for the covering force.

Representative Caliber

Artillery supporting covering forces should represent those cannon and rocket systems supporting the MBA forces. This helps deceive the enemy as to the location of our MBA.

Mobility of Fire Support

The field artillery supporting covering forces must be as mobile as the force it supports.

Fire Support Planning and Coordination

The keys to successful fire support planning for the defense, and particularly for the covering force, are staff interactions throughout the targeting process and the correct application of IPB and TVA. (See FM 6-20-10.) Initial planning should be as detailed as possible to exploit the advantages the covering force has when operating over familiar terrain with prepared defenses. Since the enemy has the initiative, predictive planning for all courses of action is necessary. Once execution begins, flexibility through detailed contingency planning is required to allow response to the unexpected.

Positioning of FA elements is a critical part of the detailed planning that must occur. A thin maneuver covering force may have to travel a greater distance to react to an enemy threat. Field artillery units may have to move laterally, forward, or to the rear to support the changing tactical situation. This requires detailed planning and rapid coordination on the part of the FSCOORD (FSO).

Fire support coordinating measures in the covering force should be permissive in nature to open the battlefield to responsive fire support. This can be done by planning successive, on-order CFLs as close to friendly troops as possible.

Crucial to the covering force battle are planning, coordinating, and executing the battle hand-over. As the battle progresses, a rearward movement will occur eventually. Maneuver units and their FSCOORDs must ensure that needed information gets back to the MBA units. Items such as targets, targeting information, status of covering force units, ammunition status, and requirements for positioning must be current. Positioning information is particularly important if control of the battle is to be passed smoothly to the MBA force. Handing over the battle and the corresponding rearward passage of lines are difficult operations that require a massive planning effort. One of the key elements of the battle hand-over is the change of command and control of fire support. Control of indirect fires passes to the MBA force as the covering force hands over the battle. The hand-over is sequenced one sector at a time until the entire security force has been withdrawn. Management of this operation is critical, since the confusion of combat may cause some covering force units to pass through different units than originally planned. Detailed coordination between the passing and stationary force commanders and FSCOORDs is essential.

Similarly, the assumption of on-order tactical missions by the passing force FA units is difficult to manage. On-order missions must be carefully planned to facilitate the likely nonlinear battle hand-over.


Execution of combat service support for security operations must be in concert with the overall operation. The CSS must be coordinated with tactical operations in the rear and in the MBA.

Sustainment of security operations is a corps responsibility. When nondivisional units are given the mission, corps support command (COSCOM) assets directly support these units. When divisions conduct security operations with division assets, the corps sustains the division in its habitual reamer.

Only those CSS assets immediately essential to the operation should be positioned forward in the security area (fuel, ammunition, medical, and limited maintenance). These assets should be withdrawn when no longer required or when the risk of their loss becomes unacceptable.



The MBA extends from the FEBA back to the rear boundary of the brigade for the division and to the rear boundary of the division for the corps. Normally, most of the defending force is deployed in the MBA to defeat the enemy's main attack. Since the decisive defensive battle is often fought in the MBA, that is where forces are concentrated. The mission of the MBA forces of the corps covers the entire spectrum of operations. Thus, while the corps as a whole may be engaged in defensive operations of the MBA, units within the corps area (divisions, brigades, and task forces) may well be conducting any or all of the following operations:

  • Defend - control a limited area or position.

  • Delay - control an enemy.

  • Attack - enemy- or terrain-oriented.

  • Security and economy-of-force tasks.

  • Forward and rear passage of lines.

  • Movement to contact.

  • Bypassed operations and/or encircled operations.

Thus, there will be differences in the way combat forces fight the defensive battle. Both heavy and light forces can conduct these operations. Task forces from the covering force join the MBA fight as they become available.

Fire Support Considerations

Fire support in the MBA is used to or destroy attacking forces. The slow, stop, enemy is detected early and attacked continuously with all available fire support means. Fires across the entire front force the enemy to deploy early into his attack formation. Fires in the economy-of-force areas are dense enough to slow or divert his supporting formations. When he masses, his formations must be attacked repeatedly and effectively with massed fires to reduce his momentum. Deep fires against the attacker's follow-on forces keep them from influencing the immediate battle.

Fire Support Tasks

Fire support tasks in defense of the MBA are as follows:

  • Mass fires to canalize and stall enemy forces, increase engagement, and destroy attacking elements.

  • Isolate enemy first-echelon elements by attacking follow-on forces.

  • Support friendly strongpoints.

  • Support obstacles to slow breaching attempts.

  • Suppress enemy air defenses.

  • Help support rear operations by fire.

  • Provide counterfires.

  • Deny the enemy use of chosen avenues of approach.

  • Suppress and obscure enemy overwatch positions.

  • Force enemy armored vehicles to button up and slow down.

  • Support counterattacks, or conduct counterattacks by fire.

  • Provide an economy-of-force measure that augments maneuver assets and frees them for other critical areas.

  • Mass fires on enemy avenues of approach.

  • Coordinate TACAIR to engage major armor formations and follow-on forces.

  • Support disengagements of maneuver elements and repositioning to subsequent battle positions.

  • Reinforce obstacles by use of FASCAM.

Allocation of Fire Support

Fire support for the MBA battle is allocated with priority to the most vulnerable area. Usually, this area coincides with the enemy's most likely avenues of approach and main attack. While fire support for the defense in general is most responsive when centrally controlled, the most vulnerable area of the MBA must be weighted more heavily with immediately responsive fires. Reinforcing field artillery, immediate CAS sorties, EW, and targeting assets can be used to provide responsive support to forces bearing the brunt of the enemy's attack.

Fire support for the MBA must be allocated as early in the estimate process as possible to allow commanders enough planning time. The proper integration of IPB and TVA gives commanders the best guess on likely enemy courses of action. This analysis is then used to prepare contingencies for the main battle. The covering force develops the situation and dictates which contingency should be executed. Appropriate fire support must be allocated for each of these contingencies. As much fire support as possible should be centrally controlled to facilitate a quick and smooth transition into any contingency plan. Fire support under centralized control allows the force commander to quickly shift combat power without moving maneuver forces.

Positioning of Field Artillery

At first, FA units may be positioned in forward supplementary positions in the MBA to allow for deeper fires. Supplementary positions should be--

  • Along routes that facilitate displacements into the main battle area.

  • Selected to provide good cover and concealment to minimize their vulnerability to enemy air attack.

As the battle develops, FA units may find themselves astride an enemy route of advance. When possible, these units should be repositioned along the flanks or deeper in the MBA. This gives maneuver forces room to operate and reduces untimely displacements during the battle. Positions selected must be coordinated with the maneuver commander responsible for the terrain, (See FM 6-20-2.)

Target Acquisition

The key to good combat information is knowing how the enemy will attack and knowing what to expect. For corps and divisions, FSCOORDs and their staffs are excellent information sources. Also, the field artillery has excellent combat communications by which to transfer this information.

In the MBA, radars should be focused on the enemy's main effort. This is where the enemy can be expected to concentrate his indirect-fire weapons. Weapons-locating radars should be positioned to maximize lateral coverage immediately forward of the MBA.

As MBA forces are repositioned to meet an enemy main effort, target acquisition elements also should be repositioned, Displacement of these resources should be staggered so that some coverage is always available.

AFSOs can provide target acquisition and can cue other TA systems. The AFSO also can hand off and designate targets for Army aviation and Air Force attack.


The handoff of the battle from covering forces to MBA forces is a critical point in the defense. Effective command and control is especially important to ensure a smooth changeover and continuous and effective fire support. Communications must be established between MBA and covering forces before control of the battle changes. This is best achieved when MBA force artillery monitors the nets used by covering force artillery before the battle hand-over.

Radio communications should preclude the following:

  • Covering force artillery having to change frequencies at a critical time.

  • Issuing additional SOI extracts to units in the covering force. This reduces the possibility of SOI compromise.

  • Early use of the MBA nets and possible detection by enemy jammers or direction-finding equipment before the MBA fight.

Suppression of Enemy Air Defenses

The heavy use of friendly aircraft may be needed during combat operations. Enemy air defenses must be suppressed to let friendly aircraft operate in the airspace above or near those defenses and their associated equipment and facilities. This requires a coordinated effort between air and land elements to locate enemy facilities and to plan and execute SEAD operations with all available lethal and nonlethal means. Usually, the land force management of SEAD fires is centered at the division main FS cell; however, SEAD planned, managed, and executed echelons.

Normally, SEAD is planned at the division main FS cell or below. Targets of concern to the air elements are processed here and assigned to appropriate fire support or EW agencies.

Because fire support is limited, the force commander must indicate his priority for SEAD targets. The FSCOORDs plan accordingly.

Individual requests by flight leaders (pilots) for SEAD support are treated as targets of opportunity (immediate targets).

Counterpreparation Fires

Counterpreparation fires may be used if the maneuver commander desires. These fires are designed to break up enemy preparations for the attack and the continuity of his attacking elements. Acquisition resources and targeting efforts are directed toward detecting enemy forward elements, indirect fire support means, observation posts, command posts, and reserves. Counterpreparations are fired when the enemy attack is imminent.

Nuclear Planning

The corps commander has the principal responsibility for operational planning and execution of nuclear fires. He develops and issues his planning guidance. The planning effort must then be focused on these contingencies and developed into the corps nuclear package. The package contains division subpackages that include nuclear fires delivered by the division artillery, Air Force, and supporting FA brigade. The corps main FS cell must know the status of all nuclear-capable delivery units.



The primary purpose of reserves in the defense is to preserve the commander's flexibility. The reserve is the commander's main means of deciding a battle in progress or of affecting future operations. The commander should decide the mission, composition, and size of the reserve on the basis of his estimate of the situation.

Reserves may be air or ground maneuver units. When the reserve is committed, all available fire support will be used to support it. The committed reserve becomes the main effort of the commander, and all combat power is concentrated there by the force.

In the mobile defense, the reserve is relied upon to strike the decisive blow. When conditions favor counterattack, the main effort shifts to the reserve, which then strikes with overwhelming combat power. The FSCOORD helps by integrating the available fire support.

Commanders can use reserves to--

  • Counterattack to exploit enemy vulnerabilities (flanks, support units, and unprotected forces in depth).

  • Reinforce forward positions.

  • Block penetrating enemy forces.

  • React to rear area threat.

Fire Support Tasks

Fire support tasks for the reserve are as follows:

  • Plan fires to support the commitment of the reserve during movement.

  • Plan fires to strike at objectives in depth as enemy dispositions are revealed. This is to support the committed reserves and to break up the enemy's coordination of the attack in the area defense.

  • Plan fires on the enemy's flanks and rear where counterattacking forces are committed in the mobile defense.

  • Plan deceptive fires to deceive the enemy into thinking the reserve is committed elsewhere.

  • Plan for fire support coordinating measures such as a restrictive fire line in case of converging forces in the mobile defense or a restrictive fire area to safeguard strongpoints in the area defense.

  • Plan to rearm, refit, and refuel organic and supporting fire support before assuming on-order missions.


In organizing the artillery for combat and in allocating other fire support, consideration must be given to the following:

  • A plan for the use of fire support organic to or habitually supporting the reserve force until it is committed.

  • Providing adequate support to the force at the time of commitment.

  • Factors of METT-T.

  • Commander's estimate of the situation.

  • Commander's intent.

As in the offense, a mission of GS or GSR is best for artillery units designated to support reserves once committed.

Once the reserve is committed, organic and habitually supporting field artillery is augmented by other lethal and nonlethal fire support. Nuclear weapons also may be considered as reserves and set aside for eventual commitment if their use has been approved by proper authority.

Unnecessary changes in organization and time-consuming movements should be avoided to ensure adequate support for the committed reserve. Timely fire support planning ensures timely support. The use of an FA brigade headquarters as a fire support planning agency for the counterattacking force should be considered. This would free the division artillery of this task.



Corps or division rear operations in a defensive posture require increased vigilance against the more pronounced threat to our rear area. Rear operations are situational and are planned for as a contingency. They are waged as the need arises and with the intensity necessary to meet the threat level. Attempts to disrupt or destroy command and control, combat support, and combat service support activities can be expected. Operations in the corps rear must be planned to deal with levels I, II, and III threats.

Defense Against Threat Activities

Bases or base clusters are responsible for their own defense against level I threats. The best defense involves aggressive preparation of fighting positions, use of camouflage, sound and aggressive guard and security procedures, well-rehearsed reaction forces, and evacuation plans. Often, the planning and reaction time is minimal. Defeat of a strong level II force requires the use of a response force and may require support by indirect fire.

The commander must allocate combat forces to defeat level III threat forces. This tactical combat force normally is a brigade equivalent at corps and a battalion equivalent at division. Fire support for the TCF should be provided for by an on-order DS mission for an artillery unit. This requires the force artillery to plan positioning of units in anticipation of that requirement. Other fire support means available may be naval gunfire, TACAIR, and Army aviation. Army aviation is particularly well suited for providing rear operations fire support because of its ability to observe the target, its mobility, and its firepower.

Fire Support

Rarely will there be enough fire support assets available to satisfy the needs of deep, close, and rear area operations at the same time. The availability and timely use of fire support in rear operations are critical to the commander's overall battle plan. Rear operations are important to sustain the MBA forces and to ensure freedom of action throughout the area of operations.

With few exceptions, indirect-fire assets should not be employed against a level I threat or against those level II threat forces that can be defeated by base or base cluster units or by the response force. These threats are usually individual or small-unit operations, are of limited scope and duration, and provide too fleeting a target for successful engagement by indirect-fire assets. However, Threat forces beyond base or base cluster self-defense capabilities may require the use of indirect-fire assets.

Operations in the rear of division or corps areas will have a profound effect on the conduct of close and deep operations. Therefore, such operations must be anticipated and plans must be devised to defeat the rear enemy. All operational plans, to include fire support for rear operations, are passed through the tactical chain of command to the rear CP.

The forces already on station are responsible for fighting the rear battle initially. The immediate problem for the force commander in providing fire support assets for rear operations is how to synchronize his limited resources at the right time and place. Considerations that affect the allocation of fire support for rear operations are as follows:

  • The reduction of fire support to the main battle effort.

  • The suitability as determined by the overall tactical situation.

  • The responsiveness of the available weapon systems.

  • The precision and collateral damage effects of the weapon systems.

  • The communications nets available to facilitate fire support activities.

  • The availability of observers to identify targets and adjust fires.

Potentially, the whole spectrum of fire support systems is available for deployment in support of rear operations. Practically, some are more suitable than others, and all depend on the factors of METT-T.

The FS cell is responsible for continuous evaluation of fire support assets available for rear operations. A prioritized list should be developed and coordinated with the operations cell of the rear CP. As close and deep operations change the status of these fire support assets, this list must be updated.

The same fire support assets and fire support coordinating measures applicable to offensive rear operations apply to defensive rear operations. (See Chapter 4.)

Fire Support Command and Control

The principles of fire support planning and coordination in the rear areas do not differ significantly from those in the forward areas. There is, however, a difference in the facilities available. Rear CPs have only limited manpower and limited communications facilities. Nevertheless, if a level III attack occurs, or if a level II attack against high-priority units cannot be neutralized by base, base cluster, or response forces, the rear area may temporarily assume an importance greater than that of the close operations. Fire support planning and coordination channels should be able to provide rapid application of fires in the rear. This requires fire support personnel to advise the rear operations commander; and it requires communications in order to plan, coordinate, and call for fire support.

The nature of command and control in rear operations varies with the echelon of command. Since there is no dedicated rear area fire support net, the operations cell must establish and disseminate the communications procedures to be used by rear area elements for planning and requesting fire support. Although they are not all-inclusive, the operations cell should consider the following options:

  • Rear area operations net (FM). The operations net may become overloaded, thus reducing fire support responsiveness.

  • Multichannel communications system (or MSE, when fielded).

  • One net from a dedicated fire support agency (such as a field artillery or attack helicopter battalion). This option provides maximum responsiveness but is not practical until the fire support agency is dedicated, not just on order.

  • A spare or alternate net identified to be used as a rear area fire support net.

While the FSO in the heavy division rear CP has a VFMED that provides a digital link with the main FS cell and the div arty CP, the FSO at the corps rear CP does not have a digital capability. Consider providing one liaison section from HHB, corps artillery, to the corps rear CP. The liaison section VFMED would provide a digital link with the corps artillery CP and the main FS cell.

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