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.

---

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.

---

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.