View source for Chapter 4: Defense

While the OPFOR sees the offense as the decisive form of military action, it recognizes defense as the stronger form of military action, particularly when faced with a superior foe. Defensive operations can lead to strategic victory if they force a stronger invading enemy to abandon his mission. It may be sufficient for the OPFOR simply not to lose. Even when an operational-level command as a whole is conducting an offensive operation, it is likely that one or more tactical-level subordinate units may be executing defensive missions to preserve offensive combat power in other areas, to protect an important formation or resource, or to deny access to key facilities or geographic areas. The same is true of subordinate units within a tactical-level command.

OPFOR defenses can be characterized as a “shield of blows.” Each force and zone of the defense plays an important role in the attack of the enemy’s combat system. A tactical-level defense is structured around the concept that disaggregating and destroying the synergy of the enemy’s combat system will make enemy forces vulnerable to attack and destruction. Commanders and staffs do not approach the defense with preconceived templates. The tactical situation may cause the commander to vary his defensive methods and techniques. Nevertheless, there are basic characteristics of defensive battles (purposes and types of action) that have applications in all situations.

=== Purpose of the Defense ===
Defensive battles are designed to achieve the goals of the battle or operation plan through active measures while preserving combat power. A tactical command ensures that its subordinate commands thoroughly understand both the overall goals of the battle plan and the specific purpose of a particular battle they are about to fight. In this way, subordinate commands can continue to fight the battle without direct control by a higher headquarters. The purpose of any given defensive battle depends on the situation, resources, and mission—as determined through the decisionmaking process. The OPFOR recognizes four general purposes of tactical defensive missions:
* Protect personnel and equipment.
* Restrict freedom of movement.
* Control key terrain.
* Gain time.
These general purposes serve as a guide to understanding the design of a defensive mission and not as a limit placed on a commander as to how he makes his intent and aim clear. These are not the only possible purposes of tactical missions but are the most common.

==== Protect Personnel and Equipment ====
A ''defense to protect key personnel and equipment'' creates one or more locations on the battlefield where forces critical to the OPFOR effort are protected from enemy reconnaissance acquisition and destructive  action. This can be because  these  elements are important  to  the  OPFOR  effort at an operational or even strategic scale or because the OPFOR needs time to reconstitute these elements for future offensive operations.

Such a defense typically, but not always relies heavily on camouflage, concealment, cover, and deception (C3D) and information warfare (INFOWAR) measures. However, enemy rules of engagement, limited access areas such as nonbelligerent countries, adverse weather conditions, and other such factors may be employed to provide protection to OPFOR forces.

==== Restrict Freedom of Movement ====
A ''defense to restrict freedom of movement'' prevents the enemy from maneuvering as he chooses. Such defenses can deny key terrain, ambush moving forces, dominate airspace, or fix an enemy formation. Tactical tasks often associated with restricting freedom of movement are ambush, block, canalize, contain, fix, interdict, and isolate.

==== Control Key Terrain ====
A ''defense to control key terrain'' prevents enemy seizure of geographic features or facilities. Terrain to be protected and controlled can include not only key terrain that dominates a battlefield, but also facilities such as economic targets, ports, or airfields.

==== Gain Time ====
A ''defense to gain time'' prevents the enemy from successfully concluding his scheme of maneuver before a certain point in time or prior to a given event taking place. A defense to gain time is not oriented on either a protected force or a geographic location—it is oriented on the enemy’s perceived scheme of maneuver. Disruption, delays, ambushes, and spoiling attacks are often parts of a defense to gain time.

=== Planning the Defense ===
For the OPFOR, the key elements of planning defensive missions are⎯
* Determining the objective of the defensive action
* Determining the level of planning possible (planned versus situational defense).
* Organizing the battlefield.
* Organizing forces and elements by function.
* Organizing INFOWAR activities in support of the defense (see chapter 7).
Defensive actions are not limited solely to attrition-based tactics. Some actions against a superior and/or equal force will typically include the increased use of⎯
* Infiltration to conduct spoiling attacks and ambushes.
* Mitigation of enemy capabilities using INFOWAR, especially perception management and computer attack (see chapter 7), in support of defensive operations.
* Use of affiliated forces for reconnaissance, counterreconnaissance, security, and attacks against key enemy systems and forces.

==== Planned Defense ====
A ''planned'' defense is a defensive mission or action undertaken when there is sufficient time and knowledge of the situation to prepare and rehearse forces for specific tasks. Typically, the enemy is in a staging or assembly area and in a known location and status. Key considerations in defensive planning are⎯
* Determining which enemy forces will attack, when, and how.
* Determining enemy weakness and how to create and/or exploit them.
* Determining key elements of the enemy’s combat system and interdict them, thereby mitigating overall enemy capability.
* Determining defensive characteristics of the terrain. Selecting key positions in complex terrain from which to dominate surrounding avenues of approach.
* Determining the method that will deny the enemy his tactical objectives.
* Developing a plan for reconnaissance, intelligence, surveillance, and target acquisition (RISTA) that locates and tracks major enemy formations, and determines enemy patterns of operations, intentions, timeframes, and probable objectives.
* Creating or taking advantage of a window of opportunity that frees friendly forces from any enemy advantages in precision standoff and situational awareness.
* Planning all aspects of an integrated counterattack making use of all means available, including INFOWAR, unmanned aerial vehicles, special-purpose forces (SPF), and/or affiliated irregular forces.

==== Situational Defense ====
The OPFOR may also conduct a ''situational'' defense. It recognizes that the modern battlefield is chaotic. Circumstances will often change so that the OPFOR is not afforded the opportunity to conduct offensive action, as originally planned, thus forcing it to adopt a defensive posture. If the OPFOR determines that a fleeting, situational window of opportunity is closing, it may assume a situational defense. Although detailed planning and preparation greatly mitigate risk, they are often not achievable if enemy action has taken away the initiative.

The following are examples of conditions that might lead to a situational defense:
* The enemy is unexpectedly striking an exposed key OPFOR unit, system, or capability.
* The enemy is conducting a spoiling attack to disrupt OPFOR offensive preparations.
* An OPFOR unit makes contact on unfavorable terms for subsequent offensive action.
* The enemy gains or regains air superiority sooner than anticipated.
* An enemy counterattack was not effectively fixed
In a situational defense, the commander develops his assessment of the conditions rapidly and without a great deal of staff involvement. He provides a basic course of action (COA) to the staff, which then quickly turns that COA into an executable combat order. Even more than other types of OPFOR defensive action, the situational defense relies on implementation of battle drills by subordinate tactical units.

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''Note''. Any division or brigade receiving additional assets from a higher command becomes a division tactical group (DTG) or brigade tactical group (BTG). Therefore, references  to  a tactical group, DTG, or BTG throughout this chapter may also apply to division or brigade, unless specifically stated otherwise.
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==== Functional Organization of Forces for the Defense--Tactical Groups, Divisions, and Brigades ====
In his combat order, the commander of a division, DTG, brigade, or BTG also specifies the initial functional organization of the forces within his level of command. However, the organization of forces can shift dramatically during the course of a battle. For example, a unit that initially was part of a disruption force may eventually occupy a battle position within the battle zone and become part of the main defense force or act as a reserve.

Each of the separate functional forces has an identified commander. This is often the senior commander of the largest subordinate unit assigned to that force. For example, if two BTGs and an independent mission detachment (IMD) are acting as the DTG’s main defense force, the senior of the two BTG commanders is the main defense force commander. During dispersed and decentralized operations, even when the force consists of like units of the same command level, control can be delegated to the senior commander of that force’s like units. Since, in this option, each force commander is also a subordinate unit commander, he controls the force from his unit’s command post (CP).

Another option is to have one of the higher unit’s CPs command and control a functional force. Particularly during dispersed defensive operations, functional forces that contain units of the same command level might be controlled from the forward, auxiliary, or airborne CP of the tactical group. For example, the forward CP could control a disruption force. Another possibility would be for the integrated fires command (IFC) CP to command the disruption force or any other force whose actions must be closely coordinated with fires delivered by the IFC.

In any case, the force commander is responsible to the division, brigade, or tactical group commander to ensure that combat preparations are made properly and to take charge of the force during the operation. This frees the higher-level commander from decisions specific to the force’s mission. Even when subordinates of a tactical group have responsibility for parts of the tactical group disruption zone, there is still an overall tactical group disruption force commander.

===== Disruption Force =====
The OPFOR commander may create a single cohesive disruption force with a single overall commander or he may create multiple (probably dispersed) forces operating in the disruption zone with numerous commanders. Activities in the disruption zone may be independent of each other, integrated, continuous, or sporadic.

The size and composition of forces in the disruption zone depends on the level of command involved, the commander’s concept of the battle, and the circumstances in which the unit adopts the defense. The function of the disruption force is to prevent the enemy from conducting an effective attack. Therefore, the size of the disruption force is not linked to any specific echelon, but rather to the function. A tactical commander will always make maximum use of stay-behind forces and affiliated forces existing within his AOR. Subordinate commanders can employ forces in a higher command’s disruption zone with tactical group approval.

While a DTG disruption force is typically a BTG, a BTG disruption force is typically an IMD. However, a disruption force has no set order of battle and will be whatever available unit(s) best fit the commanders needs. The disruption force may contain⎯
* Ambush teams (ground and air defense).
* Long-range reconnaissance patrols and/or SPF teams.
* RISTA assets and forces.
* Counterreconnaissance detachments.
* Artillery systems.
* Target designation teams.
* Elements of affiliated forces (such as guerrillas, terrorists, insurgents, or criminals).
* Antilanding reserves.
The purpose of the disruption force is to prevent the enemy from conducting an effective attack. The disruption force does this by initiating the attack on key components of the enemy’s combat system. Successful attack of designated components or subsystems begins the disaggregation of the enemy’s combat system and creates vulnerabilities for exploitation in the battle zone. Skillfully conducted disruption operations will effectively deny the enemy the synergy of effects of his combat system.

For example, the tactical group commander may determine that destruction of the  enemy’s mobility assets will create an opportunity to destroy maneuver units in the battle zone. The disruption force would be given the mission of seeking out and destroying enemy mobility assets while avoiding engagement with maneuver forces.

The disruption force may also have a counterreconnaissance mission (see chapter 6). It may selectively destroy or render irrelevant the enemy’s RISTA forces and deny him the ability to acquire and engage OPFOR targets with deep fires. It employs OPFOR RISTA assets to locate and track enemy

RISTA forces and then directs killing systems to destroy them. For this purpose, the disruption force may include operational-level RISTA assets, SPF, and helicopters. There will be times, however, when the OPFOR wants enemy reconnaissance to detect something that is part of the deception plan. In those cases, the disruption force will not seek to destroy all of the enemy’s RISTA assets.

The disruption force may deceive the enemy as to the location and configuration of the main defense in the battle zone, while forcing him to show his intent and deploy early. Some other results of actions in the disruption zone can include delaying the enemy to allow time for preparation of the defense or a counterattack, canalizing the enemy onto unfavorable axes, or ambushing key systems and vulnerable troop concentrations.

===== Main Defense Force =====
The ''main defense'' force is the functional force charged with execution of the primary defensive mission. It operates in the battle zone to accomplish the purpose of the defense. (During a maneuver defense, the main defense force is typically broken down into a contact force and a shielding force.)

===== Protected Force =====
The ''protected force'' is the force being kept from detection or destruction by the enemy. It may be in the battle zone or the support zone.

===== Security Force =====
The ''security force'' conducts activities to prevent or mitigate the effects of hostile actions against the overall command and/or its key components. If the commander chooses, he may charge this security force with providing force protection for the entire AOR, including the rest of the functional forces; logistics and administrative elements in the support zone; and other key installations, facilities, and resources.

The  security force may include various types of units⎯such as infantry,    SPF, counterreconnaissance, and signals reconnaissance assets⎯to focus on enemy special operations and long-range reconnaissance forces operating throughout the AOR. It can also include Internal Security Forces with the mission of protecting the overall command from attack by hostile insurgents, terrorists, and special operations forces. The security force may also be charged with  mitigating the effects of weapons of mass destruction (WMD). The security force commander can be given control over one or more reserve formations, such as the antilanding reserve. (See also Tactical Security in chapter 6.)

===== Counterattack Forces =====
A defensive battle may include a planned counterattack scheme. This is typical of a maneuver defense, but could also take place within an area defense. In these cases, the tactical commander will designate one or more ''counterattack forces''. He will also shift his task organization to create a counterattack force when a window of opportunity opens that leaves the enemy vulnerable to such an action. The counterattack force can have within it fixing, mission, and exploitation forces (as outlined in chapter 3). It will have the mission of causing the enemy’s offensive operation to culminate. The tactical group commander uses counterattack forces to complete the defensive mission and regain the initiative for the offense.

===== Types of Reserves =====
At the commander’s discretion, forces may be held out of initial action so that he may influence unforeseen events or take advantage of developing opportunities. He may employ a number of different types of reserve forces of varying strengths, depending on the situation.

====== Maneuver Reserve ======
The size and composition of a reserve force is entirely situation-dependent. However, the reserve is normally a force strong enough to respond to unforeseen opportunities and contingencies at the tactical level. A reserve may assume the role of counterattack force to deliver the final blow that ensures the enemy can no longer conduct his preferred COA. Reserves are almost always combined arms forces.

A reserve force will be given a list of possible missions for rehearsal and planning purposes. The staff assigns to each of these missions a priority, based on likelihood that the reserve will be called upon to execute that mission. Some missions given to the reserve may include⎯
* Conducting a counterattack. (The counterattack goal is not limited to destroying enemy forces, but may also include recovering lost positions or capturing positions advantageous for subsequent combat actions.)
* Conducting counterpenetration (blocking or destroying enemy penetrations).
* Conducting antilanding missions (eliminating vertical envelopments).
* Assisting forces heavily engaged on a defended line to break contact and withdraw.
* Acting as a deception force.

====== Antitank Reserve ======
OPFOR commanders faced with significant armored threats may keep an antitank reserve (ATR). It is generally an antitank unit and often operates in conjunction with an obstacle detachment (OD). Based on the availability of antitank and engineer assets, a division- or brigade-size unit may form more than one ATR.

====== Antilanding Reserve ======
Because of the potential threat from enemy airborne or heliborne troops, a commander may designate an antilanding reserve (ALR). While other reserves can perform this mission, the commander may create a dedicated ALR to prevent destabilization of the defense by vertical envelopment of OPFOR units or seizure of key terrain. ALRs will be resourced for rapid movement to potential drop zones (DZs) and landing zones (LZs). The ALR commander will have immediate access to the operational and tactical intelligence system for early warning of potential enemy landing operations. ALRs typically include maneuver, air defense, and engineer units, but may be allocated any unit capable  of  disrupting or defeating an airborne or heliborne landing, such as smoke or INFOWAR. ALRs assume  positions prepared to engage the enemy primary DZ or LZ as a kill zone. They rehearse and plan for rapid redeployment to other suspected DZs or LZs.

====== Special Reserves ======
In addition to their obstacle detachments (ODs), units may form an ''engineer reserve'' of earthmoving and obstacle-creating equipment. A commander can deploy this reserve to strengthen defenses on a particularly threatened axis during the course of the battle. A unit threatened by enemy use of weapons of mass destruction (WMD) may also form a ''chemical defense reserve''.

===== Deception Force =====
When the INFOWAR plan requires the creation of nonexistent or partially existing formations, these forces will be designated ''deception forces'' in close-hold executive summaries of the battle plan. Wide-distribution copies of the plan will make reference to these forces according to the designation given them in the deception story. The deception force in the defense is typically given its own command structure, both to replicate the organization(s) necessary to the deception story and to execute the multidiscipline deception required to replicate an actual military organization. Tactical group commanders can use deception forces to replicate subordinate tactical group and detachment command structures, in order to deny enemy forces information on battle plans for the defense.
----''Note''. Any battalion or company receiving additional assets from a higher command becomes a battalion-size detachment (BDET) or company-size detachment (CDET). Therefore, references to a detachment, BDET, or CDET throughout this chapter may also apply to battalion or company, unless specifically stated otherwise.
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==== Functional Organization of Elements for the Defense--Detachments, Battalions, and Below ====
Detachments, battalions, and companies employ a similar but different scheme for organizing functional elements than the functional force methodology used by tactical groups. This is because the OPFOR tends to use detachments to accomplish a single tactical task rather than a multi-task mission.

The standard functional organization of a detachment for defense is into four parts: the ''disruption element'', the ''main defense element,'' the ''support element'', and the ''reserve element''. There may ''also be specialist elements''. Due to such considerations as multiple avenues of approach, a detachment may organize one or more of each of these elements in specific cases.

The ''disruption element'' of a detachment can provide security for the detachment, prevents the enemy from influencing mission accomplishment, and prevents the enemy from conducting an effective attack by targeting key systems and subcomponents of the enemy’s combat system in the disruption zone. The ''main defense element'' accomplishes the detachment’s tactical task. The ''support element'' provides combat and combat service support and C2 for the detachment. The ''reserve element'' provides the defender with the tactical flexibility to influence unforeseen events or to take advantage of developing opportunities.

In certain situations, a detachment may organize one or more ''specialist elements''.  Specialist elements are typically formed around a unit with a specific capability such as an obstacle-clearing element, reconnaissance element, or deception element.

At any given time, a detachment will only be associated with a single functional force (disruption, main defense, security, counterattack, or reserve force) of a higher command. If a higher command needs to divide a detachment to accomplish other tasks, it will require a change in task-organizing. For example, if a BTG needed one part of one of its battalions or BDETs to serve as the main defense force, but needed another part to join the reserve, the two parts would be task-organized as separate detachments and assigned different functional element designations.

Detachments may be assigned one of several tasks while conducting a defense. Some examples are—
* Defend a simple battle position.
* Defend a complex battle position.
* Act as counterreconnaissance detachment.
* Act as deception force.
* Act as security force.
* Act as counterattack force.
* Act as reserve.

In the preparation phase, the OPFOR focuses on ways of applying all available resources and the full range of actions to conduct the defense in the strongest condition and strongest positions possible. Commanders organize the battlefield and their functional forces or elements with an eye toward capitalizing on conditions created by successful defensive actions, and seizing opportunities for offensive actions wherever possible.

The defensive dispositions are based on the application of the systems warfare  approach to combat, as described in chapter 1. OPFOR defensive actions focus on attacking components or subsystems of the enemy’s combat system to disaggregate the “system of systems.” By denying the enemy the synergy created by an integrated, aggregated combat system, vulnerabilities are created that defensive forces can exploit.

==== Deny Enemy Information ====
Tactical commanders realize that enemy operations hinge on awareness and understanding of the situation. Defensive preparations will focus on destruction and deception of enemy sensors in order to limit the ability of enemy forces to understand the OPFOR defensive plan. A high priority for all defensive preparations is to deny the enemy the ability to maintain reconnaissance contact on the ground. The OPFOR recognizes that, when conducting operations against a stronger enemy, it will often be impossible to destroy the ability of the enemy’s standoff RISTA means to observe its defensive preparations. However, the OPFOR also recognizes the reluctance of enemy military commanders to operate without human confirmation of intelligence, as well as the relative ease with which imagery and signals sensors may be deceived. OPFOR tactical commanders consider ground reconnaissance by enemy special operations forces as a significant threat in the enemy RISTA suite and will focus significant effort to ensure its removal. While the OPFOR will execute missions to destroy standoff RISTA means, C3D will be the method of choice for degrading the capability of such systems.

==== Make Thorough Countermobility and Survivability Preparations ====
The more time available, the greater the preparation of a battle position, zone, or area of responsibility (AOR). This is a reflection of engineer effort and time to devote to that effort. The OPFOR employs every method to maximize the time available to prepare for the defense.

Tactical commanders realize that engineer works are vital to the stability of the defense. They will use engineer assets to improve the advantages of complex terrain in protecting friendly forces and exposing enemy forces to engagement. Engineer efforts can contribute to creating windows of opportunity by degrading the ability of the enemy’s combat system to integrate the effects of its subsystems. Of course, such work is not just an engineer responsibility; it is a combined arms task.

Engineer units specializing in rapid obstacle construction and minelaying form mission-specific units known as obstacle detachments (ODs). These ODs normally deploy in conjunction with reserves to block enemy penetrations or to protect the flanks of counterattack forces. In the initial stages of the defense, engineer assets concentrate on creating obstacles in the disruption zone, in gaps in the combat formation, and to the flanks, and preparing lines for counterpenetration and counterattack and routes to such lines. The obstacle plan ensures that the effort is coordinated with fires and maneuver to produce the desired effects. In conjunction with other tasks, engineers support the INFORWAR plan through activities such as constructing false defensive positions and preparing false routes. See chapter 12 for more information on countermobility and survivability planning.

==== Make use of Complex Terrain ====
The OPFOR will make maximum use of complex terrain in all defensive actions. Complex terrain provides cover from fires, concealment from standoff RISTA assets, and intelligence and logistics support from the population of urban areas. It plays into the strength of OPFOR resolve to win through any means and through protracted conflict if necessary.

==== Make Thorough Logistics Arrangements ====
The overwhelming ability of a powerful, modern enemy to strike exposed logistics elements makes it difficult to resupply forces. The OPFOR understands that there is as much chance of a defensive action being brought to culmination by a lack of sufficient logistics support as there is by enemy action. Careful consideration will be given to carried days of supply and advanced caches to obviate the need for easily disrupted lines of communication (LOCs).

==== Modify the Plan When Necessary ====
The OPFOR takes into account that, while it might consider itself to be in the preparation phase for one battle, it is continuously in the execution phase. Plans are never considered final and are continually checked throughout the course of their development to ensure they are still valid in light of battlefield events.

==== Rehearse Everything Possible, in Priority ====
The commander establishes the priority for critical parts of the battle. Then he rehearses those actions with his subordinates in as realistic a manner as possible for the remainder of the preparation time. Typical actions to be rehearsed in preparation for a defense include⎯
* Counterreconnaissance plan.
* Commitment of reserve.
* Initiation of a counterattack.
* Execution of the fire support plan.
* Integration of the INFOWAR plan.

=== Executing the Defense ===
Successful execution depends on forces and elements that understand their roles in the battle and can swiftly follow preparatory actions with implementation of the battle plan or rapid modifications to the plan, as the situation requires. A successful execution phase results in the culmination of the enemy’s offensive action. It ideally ends with transition to the offense in order to keep the enemy under pressure and destroy him completely. Against a superior enemy force, however, a successful defense may end in a stalemate.

A successful defense sets the military conditions for a return to the offense or a favorable political resolution of the conflict. The OPFOR may have to surrender territory to preserve forces. Territory can always be recaptured, but the destruction of OPFOR major combat formations threatens the survival of the State. Destruction of the protected force is unacceptable.

Success criteria for a tactical commander conducting an area or maneuver defense may include⎯
* Major combat formations remain intact.
* The enemy is forced to withdraw or, at a minimum, forego offensive operations due to losses.
* A stalemate  allows  operational-, theater-, and national-level assets time  to conduct attacks against enemy strategic centers of gravity.

==== Maintain Contact ====
OPFOR commanders will go to great lengths to maintain contact with key elements of the enemy force throughout the battle. This includes rapid reconstitution of reconnaissance assets and units and the use of whatever combat power is necessary to ensure success.

==== Implement Battle Drills ====
The OPFOR derives great flexibility from battle drills. Unlike the U.S. view that battle drill, especially at higher levels, reduces flexibility, the OPFOR uses minor, simple, and clear modifications to thoroughly understood and practiced battle drills to adapt to ever-shifting conditions. It does not write standard procedures into its combat orders and does not write new orders when a simple shift from current formations and organization will do.

Battle drills are slightly less important in defensive situations, but the standardized battle drills for reacting to all seven forms of contact (direct fire, indirect fire, visual, obstacle, CBRN, electronic warfare, and air attack) will have defensive counterparts.

==== Modify the Plan When Necessary ====
The OPFOR is sensitive to the effects of mission dynamics and realizes that the enemy’s actions may well make the original mission of an OPFOR unit achievable, but completely  irrelevant.  For example, a disruption force may be capable of fixing a key element of the enemy’s attack because the enemy is using a small force to attack the OPFOR in one area while attacking strongly in another. In this case, the OPFOR unit in question must be ready to transition to a new mission quickly and break contact with sufficient combat power to fix the maneuvering enemy force. Then the original disruption force, or part of it, may be redesignated as a fixing force.

==== Seize Opportunities ====
The OPFOR places maximum emphasis on decentralized execution, initiative, and adaptation. Subordinate units are expected to take advantage of fleeting opportunities so long as their actions are in concert with the purpose of the combat order or battle plan.

=== Types of Defensive Action--Tactical Groups, Divisions, and Brigades ===
The types of defensive action in OPFOR doctrine are both tactical methods and guides to the design of operational COAs. The two basic types are maneuver and area defense. A tactical group commander may use both forms of defense simultaneously across his AOR. A defensive battle plan may include subordinate units that are executing various combinations of maneuver and area defenses, along with some offensive actions, within the overall defensive mission framework.

==== Maneuver Defense ====
In situations where the OPFOR is not completely overmatched, it may conduct a tactical ''maneuver defense''. This type of defense is designed to achieve tactical decision by skillfully using  fires  and maneuver to destroy key elements of the enemy’s combat system and deny enemy forces their objective, while preserving the friendly force. Maneuver defenses cause the enemy to continually lose effectiveness until he can no longer achieve his objectives. They can also economize force in less important areas while the OPFOR moves additional forces onto the most threatened axes.

Even within a maneuver defense, the tactical group commander may use area defense on some enemy attack axes, especially on those where he can least afford to lose ground. Conversely, he may employ maneuver defense techniques to conduct actions in the disruption zone if it enhances the attack on the enemy’s combat system and an area defense in the battle zone.

===== Method =====
Maneuver defense inflicts losses on the enemy, gains time, and protects friendly forces. It allows the defender to choose the place and time for engagements. Each portion of a maneuver defense allows a continuing attack on the enemy’s combat system. As the system begins to disaggregate, more elements are vulnerable to destruction. The maneuver defense accomplishes this through a succession of defensive battles in conjunction with short, violent counterattacks and fires. It allows abandoning some areas of terrain when responding to an unexpected enemy attack or when conducting the battle in the disruption zone. In the course of a maneuver defense, the tactical commander tries to force the enemy into a situation that exposes enemy formations to destruction. See figure 4-1 for an example of maneuver defense.

A maneuver defense trades terrain for the opportunity to destroy portions of the enemy formation and render the enemy’s combat system ineffective. The OPFOR might use a maneuver defense when⎯
* It can afford to surrender territory.
* It possesses a mobility advantage over enemy forces.
* Conditions are suitable for canalizing the enemy into areas where the OPFOR can destroy him by fire or deliver decisive counterattacks.
Compared to area defense, the maneuver defense involves a higher degree of risk for the OPFOR, because it does not always rely on the inherent advantages of complex battle positions. Units conducting a maneuver defense typically place smaller forces or elements forward in defensive positions and retain much larger reserves than in an area defense.

===== Defensive Arrays =====
The basis of maneuver defense is for units to conduct maneuver from position to position through a succession of defensive arrays. A defensive array is a group of positions in which one or more subordinate units have orders to defend for a certain time within a higher unit’s AOR. The OPFOR can accept large intervals between defensive positions in such an array. Part of the array may consist of natural or manmade obstacles or of deception defensive positions.

Defensive arrays are generally integrated into the terrain. In the spaces between arrays,  the defenders typically execute disruption. Thus, it is difficult for the enemy to predict where he will encounter resistance.

The number of arrays and duration of defense on each array depend on the nature of the enemy’s actions, the terrain, and the condition of the defending units. Arrays are selected based on the availability of obstacles and complex terrain.

===== Defensive Maneuver =====
''Defensive maneuve''r consists of movement by bounds and the maintenance of continuous fires on enemy forces. A disruption force and/or a main defense force (or part of it) can perform defensive maneuver. In either case, the force must divide its combat power into two smaller forces: a contact force and a shielding force. The ''contact force'' is the force occupying the defensive array in current or imminent contact with the enemy. The ''shielding force'' is the force occupying a defensive array that permits the contact force to reposition to a subsequent array.

The contact force ideally forces the enemy to deploy his maneuver units and perhaps begin his fires in preparation for the attack. Then, before the contact force becomes decisively engaged, it maneuvers to its next preplanned array, protected by the array occupied by the shielding force. While the original contact force is moving, the shielding force is able to keep the enemy under continuous observation, fires, and attack. When the original contact force assumes positions in its subsequent defensive array, it becomes the shielding force for the new contact force. In this manner, units continue to move by bounds to successive arrays, preserving their own forces while delaying and destroying the enemy.

Subsequent arrays are far enough apart to permit defensive maneuver by friendly units. The distance should also preclude the enemy from engaging two arrays simultaneously without displacing his indirect fire weapons. This means that the enemy, having seized a position in one array, must change the majority of his firing positions and organize his attack all over again in order to get to a position in the next array. However, the arrays are close enough to allow the defending units to maintain coordinated, continuous engagement of the enemy while moving from one to the other. It is possible that not all of the forces executing contact and shielding functions have the same number of arrays.

OPFOR commanders may require a unit occupying an array to continue defending, even if this means the unit becomes decisively engaged or enveloped. This may be necessary in order to allow time for the construction of defenses farther from contact with the enemy. This may be the case when a unit is conducting maneuver defense in the disruption zone while the main defense force is preparing for an area defense in the battle zone. At some point, a unit conducting maneuver defense as part of the main defense force may be ordered to continue to defend an array, if conditions are favorable for defeating the enemy or repelling the attack at that array.

The example of maneuver defense in figure 4-2 shows that the shielding force does not necessarily have to remain in place to do its job. It can go out to meet the enemy (perhaps in an ambush) and then maneuver into another array. This type of maneuver can force the enemy into a nonlinear fight.

===== Disruption Force =====
The disruption force initiates the attack on the enemy’s combat system by targeting and destroying subsystems that are critical to the enemy. If successful, the disruption force can cause culmination of the enemy attack before the enemy enters the battle zone. In the worst case, the enemy would enter the battle zone unable to benefit from an integrated combat system and vulnerable to defeat by the main defense force.

In a maneuver defense, the disruption force often occupies battle positions in the disruption zone and seeks to force the enemy to fight on disadvantageous ground and at a tempo of the OPFOR’s choosing. A maneuver defense disruption force also can set the conditions for a spoiling attack or counterattack (see chapter 3). The disruption force mission includes disaggregating the enemy attack and, if possible, destroying the enemy force.

Maneuver units conduct the defense from successive battle positions. Intervals between these positions provide space for deployment of mobile attack forces, precision fire systems, and reserves.

The distance between successive positions in the disruption zone is such that the enemy is forced to displace the majority of his supporting weapons to continue the attack on the subsequent positions. This aids the force in breaking contact and permits time to occupy subsequent positions. Long-range fires, ODs, and ambushes to delay pursuing enemy units can assist units in breaking contact and withdrawing.

If the disruption force has not succeeded in destroying or halting the attacking enemy, but is not under too great a pressure from a pursuing enemy, it may occupy prepared battle positions in the battle zone and assist in the remainder of the defensive mission as part of the main defense force. A disruption force may have taken losses and might not be at full capability; a heavily damaged disruption force may pass into hide positions. In that case, main defense or reserve forces occupy positions to cover the disruption force’s disengagement.

===== Main Defense Force =====
The mission of the main defense force is to complete the defeat of the enemy by engaging portions of the force exposed by actions of the disruption force and by enemy reactions to contact. This may involve resubordination of units and in some cases attacks by fire or maneuver forces across unit limits of responsibility.

The main defense force in a maneuver defense divides its combat power into contact and shielding forces. These forces move in bounds to successive arrays of defensive positions.

The basic elements of the battle zone are battle positions, firing lines, and repositioning routes. Battle positions use the terrain to protect forces while providing advantage in engagements.

The commander may order a particular unit to stand and fight long enough to repel an attack. He may order this if circumstances are favorable for defeating the enemy at that point. The unit also might have to remain in that position because the next position is still being prepared or a vertical envelopment threatens the next position or the route to it.

===== Reserves =====
A commander in the maneuver defense can employ a number of reserve forces of varying types and strengths. The maneuver reserve is a force strong enough to defeat the enemy’s exploiting force. The commander positions this reserve in an assembly area using C3D to protect it from observation and attack. From this position, it can transition to a situational defense or conduct a counterattack. The reserve must have sufficient air defense coverage and mobility assets to allow maneuver. If the commander does not commit the reserve from its original assembly area, it maneuvers to another assembly area, possibly on a different axis, where it prepares for other contingencies. (See the Types of Reserves section earlier in this chapter for discussion of other types of reserves.)

==== Area Defense ====
In situations where the OPFOR must deny key areas (or the access to them) or where it is overmatched, it may conduct a tactical area defense. Area defense is designed to achieve a decision in one of two ways:
* By forcing the enemy’s offensive operations to culminate before he can achieve his objectives.
* By denying the enemy his objectives while preserving combat power until decision can be achieved through strategic operations or operational mission accomplishment.
The area defense does not surrender the initiative to the attacking forces, but takes action to create windows of opportunity that permit forces to attack key components of the enemy’s combat system and cause unacceptable casualties. Area defense can set the conditions for destroying a key enemy force. Extended windows of opportunity permit the action of maneuver forces to prevent destruction of key positions and facilitate transition to a larger offensive action. INFOWAR is particularly important to the execution of the area defense. Deception is critical to the creation of complex battle positions, and effective perception management is vital to the creation of the windows of opportunity needed to execute maneuver and fires.

===== Method =====
Area defense inflicts losses on the enemy, retains ground, and protects friendly forces. It does so by occupying complex battle positions and dominating the surrounding area with reconnaissance fire (see chapter 9). These fires attack designated elements of the enemy’s combat system to destroy components and subsystems that create an advantage for the enemy. The intent is to begin disaggregating the enemy combat system in the disruption zone. When enemy forces enter the battle zone, they should be incapable of synchronizing combat operations. See figures 4-3 through 4-5 on pages 4-15 through 4-17  for examples of area defense.

Area defense creates windows of opportunity in which to conduct spoiling attacks or counterattacks and destroy key enemy systems. In the course of an area defense, the tactical commander uses terrain that exposes the enemy to continuing attack.

An area defense trades time for the opportunity to attack enemy forces when and where they are vulnerable. The OPFOR might use an area defense when⎯
* It is conducting access-control operations.
* Enemy forces enjoy a significant RISTA and precision standoff advantage.
* Conditions are suitable for canalizing the enemy into areas where the OPFOR can destroy him by fire and/or maneuver.
A skillfully conducted area defense can allow a significantly weaker force to defeat a stronger enemy force. However, the area defense relies to a significant degree on the availability of complex terrain and decentralized logistics. Units conducting an area defense typically execute ambushes and raids in complex terrain throughout the AOR to force the enemy into continuous operations and steadily drain his combat power and resolve.

Within an overall area defense, the OPFOR might use maneuver defense on some portions of the AOR, especially on those where it can afford to lose ground. This occurs most often as OPFOR forces and elements are initially occupying the complex terrain positions necessary for the execution of the area defense.

===== Disruption Force =====
In an area defense, the disruption zone is the area surrounding its battle zone(s) where the OPFOR may cause continuing harm to the enemy without significantly exposing itself. For example, counterreconnaissance activity may draw the attention of enemy forces and cause them to enter the kill zone of an ambush using long-range precision fires. RISTA assets and counterreconnaissance forces occupy the disruption zone, along with affiliated forces. Paramilitary forces may assist other disruption force elements by providing force protection, controlling the civilian population, and executing deception operations as directed. See figure 4-4 for an example of a disruption force in an area defense.

The disruption zone of an area defense is designed to be an area of uninterrupted battle. OPFOR RISTA elements contact with enemy forces, and other parts of the disruption force attack them incessantly with ambush and precision fires.

The disruption force has many missions. The most important mission at the tactical level is destruction of appropriate elements of the enemy’s combat system, to begin its disaggregation. The following list provides examples of other tasks a disruption force may perform:
* Detect the enemy’s main groupings.
* Force the enemy to reveal his intentions.
* Deceive the enemy as to the location and configuration of battle positions.
* Delay the enemy, allowing time for preparation of defenses and counterattacks.
* Force the enemy into premature deployment.
* Attack lucrative targets (key systems, vulnerable troops).
* Canalize the enemy into situations unfavorable to him.
The disruption force mission also includes maintaining contact with the enemy and setting the conditions for successful reconnaissance fire and counterattacks.

In an area defense, the disruption force often occupies and operates out of battle positions in the disruption zone and seeks to inflict maximum harm on selected enemy units and destroy key enemy systems operating throughout the AOR. An area defense disruption force permits the enemy no safe haven and continues to inflict damage at all hours and in all weather conditions.

Disruption force units break contact after conducting ambushes and return to battle positions for refit and resupply. Long-range fires, ODs, and ambushes to delay pursuing enemy units can assist units in breaking contact and withdrawing.

Even within the overall context of an area defense, the disruption force might employ a maneuver defense. In this case, the distance between positions in the disruption zone is such that the enemy will be forced to displace the majority of his supporting weapons to continue the attack on the subsequent positions. This aids the force in breaking contact and permits time to occupy subsequent positions.

The disruption zone will often include a significant obstacle effort. Engineer effort in the disruption zone also provides mobility support to portions of the disruption force requiring maneuver to conduct attacks or ambushes. Especially when overmatched by enemy forces, the OPFOR may use booby traps and other types of improvised obstacles.

Within the overall structure of the area defense, the disruption force seeks to conduct highly damaging local attacks. Units selected for missions in the disruption zone deploy on likely enemy avenues of approach. They choose the best terrain to inflict maximum damage on the attacking enemy and use obstacles and barriers extensively. They defend aggressively by fire and maneuver. When enemy pressure grows too strong, these forces can conduct a maneuver defense, withdrawing from one position to another in order to avoid envelopment or decisive engagement.

Since a part of the disruption force mission is to attack the enemy’s combat system, typical targets for attack by forces in the disruption zone are⎯
* C2 systems.
* RISTA assets.
* Precision fire systems.
* Aviation assets in the air and on the ground⎯at attack helicopter forward arming and refueling points (FARPs) and airfields. (Air defense ambushes are particularly effective in the disruption zone. See chapter 11).
* Logistics support areas.
* LOCs.
* Mobility and countermobility assets.
* Casualty evacuation routes and means.
In some cases, the disruption force can have a single mission of detecting and destroying a particular set of enemy capabilities. This does not mean that no other targets will be engaged. It simply means that, given a choice between targets, the disruption force will engage the targets that are the most damaging to the enemy’s combat system.

===== Main Defense Force =====
The units of the main defense force conducting an area defense occupy complex battle positions (CBPs) within the battle zone. The complex terrain is reinforced by engineer effort and C3D measures. These CBPs are designed to prevent enemy forces from being able to employ precision standoff attack means and force the enemy to choose costly methods in order to affect forces in those positions. They are also arranged in such a manner as to deny the enemy the ability to operate in covered and concealed areas himself.

The main defense force in an area defense conducts attacks and employs reconnaissance fire against enemy forces in the disruption zone. Disruption zone forces may also use the CBPs occupied by the main defense force as refit and rearm points.

===== Reserves =====
A commander in an area defense can employ a number of reserve forces of varying types and strengths. In addition to its other functions, the maneuver reserve in an area defense may have the mission of winning time for the preparation of positions. This reserve is a unit strong enough to defeat the enemy’s exploitation force in a maneuver battle during a counterattack. The commander positions its reserve in an assembly area within one or more of the battle positions, based on his concept for the battle. (See the Types of Reserves section earlier in this chapter for discussion of other types of reserves.)

=== Tactical Defensive Actions--Detachments, Battalions, and Below ===
OPFOR detachments, battalions, and companies generally participate as part of a maneuver or area defense organized by a higher command, as opposed to conducting one independently. Commanders of OPFOR detachments, battalions, or companies select the defensive action they deem to be best suited to accomplishing their mission. OPFOR detachments and below are typically called upon to execute one combat mission at a time. Therefore, it would be rare for such a unit to employ more than one of these methods simultaneously. As part of either an area defense or maneuver defense, such units often conduct tactical defensive actions employing simple battle positions (SBPs). Alternatively, as part of an area defense, they may employ complex battle positions (CBPs).

==== Battle Positions ====
A ''battle position'' (BP) is a defensive location oriented on a likely enemy avenue of approach. A BP is designed to maximize the occupying unit’s ability to accomplish its mission. A BP is selected such that the terrain in and around it is complementary to the occupying unit’s capabilities and its tactical task. There are two kinds of BPs: simple and complex (see figure 4-6).
----''Note''. Of the two types of symbol for an SBP, this TC typically uses the “goose egg” type to show an SBP occupied by a generic unit of a particular size, and the “arc” type to show an SBP of a specifically identified unit (usually a detachment or below). Sometimes graphics show a large unit, such as a BTG or even a DTG inside a symbol for a CBP. This actually means that such a unit’s subordinates occupy a series of CBPs within that area.
----

===== Simple Battle Position =====
A ''simple battle position'' (SBP) is a defensive location oriented on the most likely enemy avenue of approach. SBPs are not necessarily tied to complex terrain. However, they often employ as much engineer effort and/or camouflage, concealment, cover, and deception (C3D) measures as time allows.

===== Complex Battle Position =====
A ''complex battle position'' (CBP) is a defensive location designed to employ a combination of complex terrain, C3D, and engineer effort to protect the unit(s) within them from detection and attack while denying their seizure and occupation by the enemy. CBPs typically have the following characteristics that distinguish them from SBPs:
* Limited avenues of approach. (CBPs are not necessarily tied to an avenue of approach.)
* Any existing avenues of approach are easily observable by the defender.
* 360-degree fire  coverage  and  protection  from  attack.  (This may  be  due  to the  nature of surrounding terrain or engineer activity such as tunneling.)
* Engineer effort prioritizing C3D measures; limited countermobility effort that might reveal the CBP location.
* Large logistics caches.
* Sanctuary from which to launch local attacks.

==== Defense of a Simple Battle Position ====
An SBP is typically oriented on the most likely enemy avenue of approach. SBPs may or may not be tied to restrictive terrain but will employ as much engineer effort as possible to restrict enemy maneuver. Defenders of SBPs will take all actions necessary to prevent enemy penetration of their position, or defeat a penetration once it has occurred.

===== Functional Organization of Elements to Defend an SBP =====
The commander of a detachment, battalion, or company defending an SBP designates his subordinate units as functional elements. The name of the element describes its function within the defensive action.

====== Disruption Element ======
Unit(s) assigned to the disruption element have the mission of defeating enemy reconnaissance efforts; determining the location, disposition, and composition of attacking forces; and in some cases they will also target designated subsystems of the attacking enemy’s combat system. To accomplish these tasks, the disruption element may form combat security outposts (CSOPs) and ambush teams.

'''CSOPs.''' CSOPs prevent enemy reconnaissance or small groups from penetrating friendly positions and force the enemy to prematurely deploy and lose his momentum in the attack. CSOPs are generally composed of task-organized platoon- or squad-size elements. In a battalion or BDET, the platoon or squad(s) forming the CSOP is generally drawn from the battalion reserve element. Companies or CDETs may also form their own CSOPs. CSOPs are positioned forward of the battle zone on key terrain or along key avenues of approach. They typically will not be positioned directly astride avenues of approach into kill zones, but may cover them with fire. If decisively overmatched by enemy combat power, CSOPs may withdraw to the battle zone. An OPFOR battalion or BDET may employ more than one CSOP. During the counterreconnaissance battle, other forces may augment CSOPs, covering those avenues of approach that the CSOPs do not cover. CSOPs are typically assigned one or more of the following tactical tasks:
* '''Ambush.''' A CSOP with this task generally will avoid contact with superior enemy forces and only engage key enemy targets. When assigning this task, the OPFOR commander must also describe desired effects on the enemy (such as destroy, fix, or suppress).
* '''Attack by fire.''' A CSOP with this task is normally attempting to shape the battlefield in some fashion, either by turning an attacking enemy force into a kill zone or by denying the enemy a key piece of terrain. A CSOP with this task may also be required to target a key element of the enemy force.
* '''Delay.''' A CSOP with this task will attempt to buy time for the OPFOR to accomplish some other task such as defensive preparations, launch a counterattack, or complete a withdrawal. Normally, the CSOP will withdraw (remaining in the disruption zone, or moving to the battle or support zone) after engaging for a set amount of time.
* '''Disrupt.''' A CSOP with this task will attempt to weaken an enemy attack by using fires to cause premature commitment of the enemy, break apart his formation, and desynchronize his plan.
* '''Fix.''' A CSOP with this task will use fires to prevent a key element of the enemy force from moving from a specific place or halt them for a specific amount of time.
See figure 4-7 for an example of a CSOP.

'''Ambush Teams.''' Ambush teams (independent from CSOPs) remain concealed forward of the battle zone, and may allow some enemy forces to bypass their position. Once they identify key enemy targets, they will engage them by employing flanking or surprise close-range fire.

====== Main Defense Element ======
The main defense element of an SBP is responsible for defeating an attacking force, and for maneuvering to defeat the penetration or seizure of other SBPs. For examples of a CDET in an SBP, see figures 4-8 and 4-9 on pages 4-22 and 4-23.

====== Reserve Element ======
The reserve element of an SBP exists to provide the OPFOR commander with tactical flexibility. During the counterreconnaissance battle, the reserve may augment forces in the disruption zone, in order to provide additional security to the main defense element. During this time, the reserve element will also rehearse potential counterattack routes, although to avoid detection it will rarely do so en masse. Once a significant attacking force is detected, the reserve element will withdraw to a covered and concealed position, conduct resupply, and prepare for additional tasks. Some typical additional tasks given to the reserve may include—
* Conducting a counterattack.
* Conducting counterpenetration (blocking or destroying enemy penetration of the SBP).
* Conducting antilanding defense.
* Assisting engaged forces in breaking contact.
* Acting as a deception element.

====== Support Element ======
The support element of an SBP has the mission of providing one or more of the following to the defending force:
* Combat service support (CSS).
* C2.
* Supporting direct fire (such as heavy machinegun, antitank guided missile [ATGM], recoilless rifle, or automatic grenade launcher).
* Supporting indirect fire (mortar or artillery).
* Supporting nonlethal actions (for example, jamming, psychological warfare, or broadcasts).
* Engineer support.

===== Organizing the Battlefield for an SBP =====
A detachment, battalion or company commander specifies the organization of the battlefield from the perspective of his level of command. As at higher levels, this normally consists of a battle zone and a support zone. It may also include a disruption zone.

====== Disruption Zone ======
The disruption zone is the area forward of the battle zone where the defenders will seek to defeat enemy reconnaissance efforts, detect attacking forces, disrupt and delay an  attackers approach,  and destroy key attacking elements prior to engagement in the battle zone. A defense of an SBP may or may not include a disruption zone.

====== Battle Zone ======
The battle zone is the area where the defending commander commits the preponderance of his force to the task of defeating attacking enemy forces. Generally, an SBP will have its battle zone fires integrated with those of any adjacent SBPs. Fires will orient to form kill zones where the OPFOR plans to destroy key enemy targets. When possible, kill zones will be placed on the reverse slope of intervisibility lines within the battle zone.

'''Reverse Slope Defense.''' The OPFOR commander will seek a defensive position behind a terrain feature(s) that, in addition to providing an intervisibility line, canalizes attackers into narrow attack frontages that lead into the kill zone. A reverse slope defense is positioned behind an intervisibility line so that is masked from enemy observation and direct fire. The defense is based upon employing the intervisibility line to protect friendly forces and isolate portions of the attacking force as they cross the crest. Although the OPFOR may not occupy the crest in strength, it will control it by fire. OPFOR commanders prefer a reverse slope defensive position because it confers the following advantages:
* It hinders or prevents enemy observation of the defensive position.
* Attacking forces are not able to receive direct fire support from follow-on forces.
* It can negate an enemy stand-off fire advantage
* Attacking enemy forces are silhouetted while crossing the crest of the intervisibility line.
* Engineers can conduct their work out of direct fire and observation from the enemy.
In some cases, the adoption of a reverse slope defense can prevent the defender’s weapon systems from exploiting their maximum range. However, skilful OPFOR commanders will select defensive terrain that allows them to maximize their weapons stand-off range. They do so by emplacing their systems at their maximum effective range behind the crest of the intervisibility line that supports their kill zone. This may mean placing a weapon system on the counterslope behind the terrain forming the intervisibility line.

Maintaining observation of the enemy while on the forward slope of an intervisibility line can be difficult. To alleviate this disadvantage, OPFOR commanders will employ reconnaissance assets to observe forward of the reverse slope defensive position.

'''Fire Planning.''' Fire is the basic means of destroying the enemy in the defense. To perform this task, the OPFOR will employ lethal and nonlethal weaponry in a unified manner, often directed into a kill zone. The normal basis of a battalion’s or BDET’s system of fire is the antitank (AT) fire of its companies (and any additional units task-organized into the BDET) and supporting artillery. In areas that are not accessible to vehicles, the basis of fire will primarily be machinegun, grenade launcher, mortar, and artillery fires. In this case, where possible, AT systems will be employed in an antipersonnel role.

During the OPFOR fire planning process, the commander and staff delineate key enemy targets. The planners then appoint reconnaissance elements to identify targets and weapons systems to engage them. The OPFOR battalion’s or BDET’s fire planning includes sectors of concentrated fire and barrier fire lines of artillery and mortars in the disruption zone, on flanks, and throughout the depth of the battle zone. Subordinate units and weapons are expected to coordinate with each other as well as flanks units in the coverage of kill zones.

Kill zones will be covered by frontal and flanking or cross fires of the OPFOR battalion’s or BDET’s and other supporting weapons systems. The OPFOR will employ obstacles and fire concentrations to halt and hold the enemy within kill zones. Terrain considerations and available weaponry will dictate the size of the kill zone and the width of the OPFOR defense.

====== Support Zone ======
The support zone may contain C2, CSS, indirect and direct support fire assets, and the reserve, as well as other supporting assets. The support zone will normally be located in the SBP. Support zones are not typically found below the company level.

===== Executing Defense of an SBP =====
SBP defenders will conduct aggressive counterreconnaissance throughout their occupation of the battle position. Such counterreconnaissance will occur primarily in the disruption zone, but measures will also be taken in the battle and support zones. OPFOR electronic warfare assets will attempt to detect the presence and location of enemy reconnaissance elements. The reserve element may act as a quick- response force to destroy any enemy reconnaissance assets discovered in the battle or support zones. Once a significant attacking force is detected, the OPFOR will employ fires (direct or indirect) to delay and attrit attackers in the disruption zone.

====== Battle Zone ======
Defenders in the battle zone will attempt to defeat attacking forces. Should the enemy penetrate the main defenses or capture a position, defenders will take measures to defeat the  penetration or recapture the position, to include the commitment of reserves and repositioning forces from other areas within the SBP.

====== Support Zone ======
Defenders in the support zone will provide support to defenders in the disruption and battle zones as required. In the event of the defeat or penetration of the SBP, they will maneuver as needed to avoid destruction or to support counterattacks.

====== Deception ======
To keep the enemy from discovering the nature of the OPFOR defenses and to draw fire away from actual units, defenders will establish dummy firing positions and battle positions. In addition to enhancing force protection, the OPFOR will employ deception positions as an economy-of-force measure to portray strength. These measures will include the creation of false entrenchments, heat signatures, and dummy vehicles.

===== Command and Control of an SBP =====
To maintain security during defensive preparations, defenders will make all possible use of secure communications, such as couriers and wire. However, once the main battle is joined, communications measures will tend to be those that support maneuver, such as radio and cellular technology.

===== Support of an SBP =====
4-132. Depending on the situation, the SBP will require support. This support may include combat support (CS) and/or CSS or a mixture of both. While some of this support will be provided from within the parent organization, other support may be from other organizations.

====== Reconnaissance ======
SBP defenders will perform aggressive counterreconnaissance activities to prevent the enemy from remaining in reconnaissance contact with the SBP. The OPFOR will observe avenues of approach to provide early warning; determine location, composition, and disposition of attackers; and direct fires against key enemy systems or components of systems. Figure 4-10 is an example of reconnaissance in support of an SBP. In this example, each of the three squads of the BDET’s reconnaissance platoon serves as an observation post (OP).

====== Armored Fighting Vehicles ======
When employed within an SBP, armored fighting vehicles will typically serve an anti-armor role, but can also serve as in an anti-infantry role. They may also be massed as a counterattack reserve. Defending armored vehicles will be in two-tier (turret defilade) vehicle fighting positions to provide maximum cover and concealment, or will fight above ground to take maximum advantage of maneuver capabilities. Armored vehicles defending SBPs do not prefer single-tier (hull defilade) vehicle fighting positions, since they provide insufficient cover and concealment against precision munitions and restrict vehicular mobility.

====== Fire Support ======
SBPs may receive fire support both from constituent assets and from higher echelon supporting forces. Fire support is integrated with other adjacent units to ensure appropriate coverage. Defenders will employ fires to—
* Attrit attackers along the avenues of approach and in LZs.
* Defeat attackers in the battle zone.
* Defeat penetrations of battle positions.
* Support counterattacking forces.

====== Air Defense ======
SBPs employ both active and passive air defense measures to protect the defender from air threats. Antiaircraft guns and shoulder-fired surface-to-air missiles (SAMs) may be found interspersed throughout the SBP, including antilanding ambushes. Electronically integrated air defense systems may be present when allocated to the defending force from higher-echelon supporting units.

====== Engineer ======
When available, engineers support the SBP initially by preparing survivability positions and countermobility works that support the disruption and battle zones. Once these preparations are complete, engineer support will shift to mobility support for the reserve force to ensure that it maintains freedom of maneuver.

Engineer tasks are a shared responsibility throughout the OPFOR. Although engineers have the bulk of specialized equipment for constructing fortified positions, this work exceeds the capability of organic constituent engineers and even those likely allocated from higher command. Therefore, the OPFOR uses all available personnel and equipment.

SBP obstacles are normally employed to shape the battlefield by disrupting the enemy’s approach march, blocking avenues of approach, and turning the enemy into and fixing him in kill zones. Should the OPFOR have a remotely delivered mine capability, it will be used to reinforce pre-existing obstacles, block avenues of approach, or to re-seed breached obstacles.

Tables 4-1 through 4-3 on pages 4-27, 4-28, and 4-29 show preparation tasks for a battalion or BDET battle position (either simple or complex). Table 4-1 shows tasks that are the first priority in the sequence of position preparation. Combat arms unit personnel clear fields of fire and view. Then they emplace barbed wire, mines, and other obstacles in front of each fighting vehicle, crew-served weapon, and individual infantryman. Personnel use open slit trenches. Using covered slit trenches, engineers dig in headquarters and medical points. Camouflage measures are also performed. If the situation permits, engineers will employ excavating and earthmoving equipment.