CHAPTER 4

DEFENSIVE OPERATIONS

This chapter describes the planning, preparation, and execution of defensive operations. It emphasizes the requirement for initiative and the need to accept risk in one part of the battlefield in order to mass combat power in another. The defense employs offensive, defensive, and delaying actions to destroy the enemy. To be successful, the task force commander must attack the enemy with concentrated fires and maneuver throughout the battlefield.

CONTENTS

Section I. FUNDAMENTALS OF THE DEFENSE

4-1 Purpose of Defense

4-2 Characteristics of Defensive Operations

4-3 Framework of the Defense

Section II. THREAT OFFENSIVE DOCTRINE

4-4 Threat Attack Planning

4-5 How the Threat Attacks

Section III. PLANNING FOR DEFENSIVE OPERATIONS

4-6 Planning

4-7 Defensive IPB

4-8 Unit Positioning

4-9 Combat Support

4-10 Additional Considerations

4-11 Synchronization of Defensive Operations

4-12 Sequence of the Defense

4-13 Battle Handover

Section IV. TYPES OF DEFENSE

4-14 Defense of a Sector

4-15 Defense of a Battle Position

4-16 Defense of a Strongpoint

Section V. RESERVE OPERATIONS

4-17 Counterattack

4-18 Spoiling Attack

4-19 Block, Fix, or Contain

4-20 Reinforce

4-21 Rear Operations

Section VI. OTHER DEFENSIVE OPERATIONS AND TECHNIQUES

4-22 Counterreconnaissance Operations

4-23 Stay-Behind/Hide Forces

4-24 Perimeter Defense

4-25 Reverse Slope Defense

4-26 Urban Area Operations

Section I. FUNDAMENTALS OF THE DEFENSE

AirLand Battle doctrine stresses gaining the initiative through offensive action. In defensive operations, this implies the ability to make a quick transition to the offense by maintaining a reserve force and shaping the battlefield to make counterattacks possible. The task force may defend in sector, from battle positions, and from strongpoints. Supporting fires and reinforcing obstacles are planned to assist in shaping the battlefield, to slow and confuse the enemy, and to destroy the continuity of enemy formations.

The defensive positions are usually nonlinear, and the battle is planned and fought in depth. The battle starts forward of the FEBA. Supporting indirect fires are planned and used as early as tactically feasible. The initiative must be taken from the attacking enemy, and he may be attacked before he closes on the MBA. A reserve should be available to counterattack at the critical point to destroy the enemy and halt his advance. The defense orients on defeating the enemy, not on maintaining the initial FEBA trace. Flexibility and concentration are the keys to the defense. Forward company teams not being attacked reposition or counterattack to contribute to the battle.

4-1. PURPOSE OF DEFENSE

The purpose of defense is to defeat the enemy's attack and gain the initiative for offensive operations. Defense is a temporary measure conducted to identify or create enemy weaknesses that allow for the early opportunity to change over to the offense. Defensive operations achieve one or more of the following:

4-2. CHARACTERISTICS OF DEFENSIVE OPERATIONS

a. Preparation.

(1) The defender has significant advantages over the attacker. In most cases, he not only knows the ground better, but, having occupied it first, he has strengthened his positions. He is stationary and under cover in carefully selected positions, with prepared fires and obstacles.

(2) The attacker, however, has the initiative to choose the time and place of battle. The attacker tries to shatter the defense quickly and prevent its reconstitution by continuing the attack at a fast pace. The defender must slow the attacker's tempo, thereby providing time to isolate, fight, and destroy the attacker.

(3) Operational security is the defender's first requirement to defeat an attack. Units must maintain operational security, avoid patterns, and practice deception to hide the defender's disposition. Enemy reconnaissance efforts and probing attacks must be defeated without disclosing the scheme of defense. The reconnaissance battle is normally a prelude to the larger battle. The winner of the reconnaissance battle is usually the winner of the final battle.

(4) An enemy attack is preceded and accompanied by massed supporting fires. To survive, units must use defilade, reverse slope, and hide positions; use supporting and suppressive fires; and avoid easily targeted locations. The defender must use all available time to prepare fighting positions and obstacles, to rehearse counterattacks, and to plan supporting fires and combat service support in detail.

b. Disruption. An attacker's strength comes from momentum, mass, and mutual support of maneuver and combat support elements. The defender must slow or fix the attack, disrupt the attacker's mass, and break up the mutual support between the attacker's combat and combat support elements. This results in a piecemeal attack that can be defeated in detail. A general aim is to force the attacker to fight a nonlinear battle to make the attacker fight in more than one direction. This makes it more difficult for him to coordinate and concentrate forces and fires, and to isolate and overwhelm the defender. It also makes the securing of his flanks, combat support, combat service support, and command and control elements more difficult.

c. Concentration. To gain local superiority in one area, the defender is often forced to economize and accept risks elsewhere. Reconnaissance and security forces enable him to "see" the battlefield, and thereby reduce risk. The defender should be able to rapidly concentrate forces, thereby massing combat power to defeat an attacking force, then disperse and be prepared to concentrate again. The main effort is assigned to one subordinate unit. All other elements and assets support and sustain this effort. The commander may shift his focus by designating a new unit to be the main effort if other units encounter unexpected difficulties or achieve success.

d. Flexibility. Commanders designate reserves and deploy forces and logistic resources in depth to ensure continuous operations and to provide options for the defender if forward positions are penetrated.

(1) Contingency planning permits rapid action. Understanding the commander's intent and contingency plans allows subordinate commanders to rapidly exploit enemy weaknesses.

(2) Flexibility also requires that the commander "see the battlefield" to detect the enemy's scheme of maneuver in time to direct fires and maneuver against it. IPB determines likely enemy actions, while security elements verify which actions are actually taking place. The commander does not limit his intelligence gathering efforts only to the forces in contact, but also concentrates on formations arrayed in depth. The enemy may attempt to bypass areas where the defense is strong. Hence, the defending commander ensures that he is able to detect and react to enemy movement along all possible avenues of approach throughout the course of the battle. The defender must never allow the attacker to gain tactical surprise.

4-3. FRAMEWORK OF THE DEFENSE

The task force normally defends as part of a larger force. The defensive framework within which corps and divisions organize and fight is organized into five elements (see Figure 4-1):

a. Deep Operations.

(1) Deep operations are actions against those enemy forces not yet in direct contact with the FLOT. Deep operations create opportunities for offensive action by reducing the enemy's closure rates; separating attacking echelons; disrupting his command and control, combat support, and combat service support; and slowing the arrival times of succeeding echelons. Deep operations are conducted using indirect fires, EW, Air Force and Army aviation, deception, and maneuver forces.

(2) Task forces have no deep operations capabilities, although they may be part of a deep maneuver operation.

b. Close Operations.

(1) Security area operations.

(a) The forward security force normally established by corps is called a covering force. It begins the fight against the attacker's leading echelons in the covering force area (CFA). Covering force actions weaken the enemy; permit the corps commander to reposition forces; and deceive the enemy as to the size, location, and strength of the defense.

(b) A battalion task force may fight as a part of a covering force operation. When it disengages from the enemy, it becomes part of the MBA forces or reserve. MBA units assume control of the covering force battle at the battle handover line and assist covering force units to break contact and withdraw through the MBA.

(2) Main battle area operations.

(a) Based on their estimate of the situation and intent, brigade commanders assign sectors or battle positions to task forces. Normally, assigned sectors coincide with a major avenue of approach, while battle positions and attack helicopter firing positions are on the flanks of main approaches. The brigade commander designates and sustains the main effort by giving priority of artillery, engineer, air defense, and close air support assets to the force responsible for the most dangerous avenue of approach into the MBA. The commander can strengthen the effort on the most dangerous avenue by narrowing the sector of the unit astride it.

(b) Task force commanders structure their defenses by deploying units in depth within the MBA. A mounted reserve of one-quarter to one-half of the task force strength provides additional depth and gives the commander a maneuver capability against the enemy. A commander can create a reserve by taking risk on less likely enemy avenues of approach in the MBA.

(c) Penetration by enemy forces must be anticipated and provided for in the plan. Separation of adjacent units is likely, especially if the enemy is conducting nuclear and chemical operations. MBA forces continue to strike at the enemy's flank, and counterattack across penetrations.

(3) Reserve operations.

(a) The commitment of reserve forces at the decisive point and time is key to the success of a defense. When the task force has been designated as a reserve force, it can expect to receive one or more of the following missions: counterattack; spoiling attack; block, fix, or contain; reinforce; or rear operations (see Section V).

(b) When the task force designates a reserve, its most common use is in the counterattack role. The composition, location, and mission of a reserve is based on the task force commander's estimate of the situation and intent.

c. Rear Operations. The battalion task force does not have a rear operations fight within its assigned sector. However, a maneuver battalion assigned a rear mission by a higher headquarters may conduct offensive operations against enemy conventional or unconventional forces in the rear area.

Section II. THREAT OFFENSIVE DOCTRINE

When planning, preparing, and executing the defensive operation, the battalion commander and his staff must know how the threat will attack. This knowledge leads to an identification of probable courses of action, weaknesses, and vulnerabilities of the threat attack.

4-4. THREAT ATTACK PLANNING

a. The Threat regiment will attempt to attack along brigade and battalion boundaries--where we are weakest. His objective will be a location or facility in the rear area. He will always mass and position his strength against known weaknesses, terrain being considered equal. He identifies weaknesses through an aggressive reconnaissance effort before the attack. He will generally accept the problems inherent in marginal and adverse terrain rather than go against friendly strength. He studies terrain as only a limiting factor after he forms his initial attack concept. His use of deception to mask his timing, location, and or scope of the attack will be the norm rather than the exception.

b. To carry out his attack, the threat commander expects to have an 80 percent complete intelligence picture of the battalions' initial and subsequent defensive positions. He will mass his forces to achieve at least a 3:1 superiority for his main attack.

c. His attack will be preceded by strong concentrations of artillery within the main attack. Threat doctrine calls for 60 to 100 tubes of artillery per kilometer of main attack frontage.

4-5. HOW THE THREAT ATTACKS

The Threat strives to sustain continuous operations with overwhelming numbers through momentum, mass, and echelonment. The Threat uses combined arms formations of massed tanks, motorized (mechanized) infantry, and other armored vehicles supported by massed fires. See Figure 4-2 for an example Threat motorized rifle regiment attack.

Section III. PLANNING FOR DEFENSIVE OPERATIONS

This section implements QSTAG 567.

The defense is planned in detail, but the commander must remain flexible and willing to deviate from the plan when circumstances dictate or opportunities present themselves.

4-6. PLANNING

a. The brigade order must be analyzed not only for specified and implied tasks but also for intent and the maneuver required to accomplish that intent. The following questions may assist the planner in this analysis.

(1) Is decisive engagement to be accepted, or is freedom of maneuver to be retained?

(2) How are the brigade and division going to create weaknesses? How and with what forces are they going to attack weaknesses?

(3) How are counterattacks to be conducted, coordinated, and supported?

(4) How is the task force to tie in with adjacent units?

(5) Is there decisive terrain to be retained?

(6) What are subsequent missions? Contingency plans?

b. General battalion task force defensive missions include defend, delay, and counterattack.

(1) The mission to defend can apply to a sector, a battle position, or a strongpoint.

(a) Defense in sector requires the task force to defeat the attacker forward of the rear boundary. The task force may fight the battle using the entire depth of the sector consistent with the intent of the brigade commander and the requirement to tie in with adjacent units.

(b) Defense of a battle position requires the task force to occupy a general location from which it can block an avenue of approach, fire into an assigned area, retain key terrain, or perform other tasks.

(c) Defense of a strongpoint implies defense of an extensively fortified position that holds or controls decisive terrain or blocks an avenue of approach.

(2) Delay missions allow the forfeiture of terrain to gain time. Delays shape and deplete the enemy while giving other friendly units time to prepare.

(3) Counterattack can be by fire or maneuver (fire and movement).

(a) Counterattack by fire requires movement to a position to destroy the attacker by fire. The enemy force is the primary objective. Terrain seized is important only for as long as the enemy can be engaged from that location.

(b) Counterattack by maneuver implies the intent to close with and destroy the enemy or to capture key terrain.

c. Besides the basic missions of defend, delay, and counterattack, numerous other tasks may be specified or implied in the brigade order. Examples are assisting the passage of covering or security forces, providing security, preparing obstacles, and providing surveillance or intelligence.

4-7. DEFENSIVE IPB

During IPB, the commander and his staff consider weather, enemy, and terrain to determine and analyze ground and air avenues of approach. Specific considerations for the analysis of avenues of approach include the following.

a. Determining primary and secondary avenues of approach and mobility corridors.

b. Determining key and decisive terrain. The staff identifies areas along the avenues of approach where speed and deployment of enemy formations is limited and where formations are broken up and exposed to counterattack. Key and decisive terrain will facilitate blocking the avenue of approach.

c. Determining FROM THE ENEMY'S POINT OF VIEW--

(1) Maneuver space. Considering choke points and natural obstacles, how many armored vehicles and, hence, what size unit does each avenue of approach support?

(2) Trafficability. How do soil trafficability, ruggedness of terrain, weather, and limited visibility affect movement rates?

(3) Cover and concealment. What terrain allows movement as close to the defender as possible using column formations before deploying into assault formations?

(4) Observation and fields of fire. What terrain is suitable for supporting direct fire by tanks, ATGMs, attack helicopters, or self-propelled artillery?

(5) Key/decisive terrain. What terrain gives the enemy a decided advantage over the defender?

(6) Limited visibility effects. Smoke, dust, fog, and darkness all affect movement. During such periods, roads, ridgelines, and other features that facilitate navigation increase the value of an avenue of approach.

(7) Enemy air avenues of approach.

d. Determining possible and probable enemy courses of action.

e. Developing named areas of interest and target areas of interest to determine the attacker's intent and lessen friendly reaction time.

4-8. UNIT POSITIONING

The commander decides where to defeat the enemy based on IPB determination of avenues of approach, key terrain, and enemy vulnerabilities. He and his staff then develop courses of action and determine tentative unit positions.

a. The task force commander arrays company-size forces against battalion-size avenues of approach. In doing this, he considers the positioning of platoons. The positions must provide for an integrated defense so that all available weapons systems can cover the approaches. Positioning should allow the shifting of fires and forces to meet enemy actions during the battle. Once this is completed, consideration is given to the formation of company teams.

b. The task force organizes and assigns missions in the defense based on the factors of METT-T and considers the following:

(1) Dispersion. Units and weapons are dispersed laterally and in depth to reduce the enemy's ability to suppress, and to hit the enemy from multiple directions.

(2) Cover and concealment. Elements are placed in positions where cover and concealment are available; obvious terrain is avoided. Hide positions are used. A technique to check the adequacy of concealment is to travel approaches from the enemy's direction of movement. Covered routes must be available to allow movement in and between positions and for maneuver against the enemy.

(3) Flanking fire. Flanking fires are far more effective than frontal fires. Initial positioning of antiarmor weapons for long-range engagements is considered, but primary positions are normally picked to allow flanking fires from defilade positions.

(4) Security. Position security must include patrolling, OPs, and other measures to provide security. Scouts may be augmented to perform counterreconnaissance tasks or company teams may be given security missions forward of the FEBA.

(5) Ability to maneuver. Units must be able to concentrate on the avenues of approach being used by the enemy. To do this, on-order positions with sectors of fire and positions in depth are used.

(6) Range of weapons systems. When selecting tentative positions for weapons systems, the task force commander must also consider the effective range and acquisition capabilities of each system. Tanks are positioned to begin engagement of enemy tanks at 2,500 meters. ITVs engage tanks out to 3,750 meters (3,000 preferred). GLLDs with their long-range designation capability (3,000 to 5,000 meters for moving or stationary targets respectively) and their requirement to be within 800 roils of the gun-target line may compete with ITVs for positioning. The BFV's 25-mm gun is effective against BMPs, BTRs, and BRDMs with a planning range of 1,700 meters. Dragons allow infantry to defeat flanked armor at ranges up to 1,000 (800 preferred) meters and light antitank weapons at ranges of 200 meters (150 preferred). Attack helicopters in an antitank role have a maximum range of 3,750 meters for the AH-1S and 5,000 meters for the AH-64. The commander considers these capabilities when selecting engagement areas, positioning obstacles, designing his defense, and issuing his engagement and withdrawal criteria.

(7) Transition to limited visibility fighting positions. An attacker uses smoke and suppressive fire to limit visibility. The defenders must anticipate and be prepared to move rapidly to predetermined, limited visibility fighting positions.

(8) Subordinate missions. The task force commander sets his scheme of maneuver into motion by assigning missions to company teams. He task-organizes to give each team the required assets. He allocates space using sectors, battle positions, and strongpoints, and gives specific tasks for each. Engagement areas, TRPs, terrain that must be held, and counterattack missions are also included as required. The task force commander states whether his company teams may accept decisive engagement. When explaining his concept, the task force commander states disengagement criteria. He informs each company team commander of the conditions under which to disengage (for example, when the enemy reaches a point on the ground, or after destroying a certain number of vehicles, or at a certain time or event, or do not disengage until ordered to do so).

(a) In assigning a mission of holding terrain, the task force commander considers that significant time is required to hold a battle position and that more time and resources are required for a strongpoint. Infantry-pure companies or infantry-heavy teams are best suited for retain missions.

(b) If there are more missions than combat elements available to perform them, a reserve may be designated and tasked to perform these missions on order.

(c) When assigning space, the task force commander ensures that company teams have room to position weapons and to disperse from enemy direct and indirect fires and observation. In relatively open terrain, the distance between ITVs, BFVs, and tanks should be about 150 meters. The commander must consider space requirements for alternate and supplementary positions when he allocates space.

(d) Subordinates must know how the battle is to be fought and what their roles are to be. This includes knowledge of fire control measures (TRPs, EAs), areas to be covered by fire, requirements for obstacle emplacement, security, and on-order missions in priority.

(e) The defense plans include the rapid maneuver of forces to attack the enemy's flanks and rear. Maneuver also serves to confuse the attacker, as when a unit moves from a position occupied initially with no intent to fight from it. The task force commander must plan and rehearse maneuver to the extent that time allows.

c. Tanks are a key element in counterattacks. They can fire on the move and have a faster rate of fire and shorter engagement time than missiles. Tanks should be used to cover the most dangerous armor avenues of approach, and the reserve force should be built around tanks.

d. Antitank missiles provide long-range fires but are limited by rate of fire and time of flight. They are positioned to maximize their standoff capacity, normally from flanking positions into relatively open areas that allow tracking. They may also be used as "sniper" weapons for destroying enemy reconnaissance or advance guard elements from alternate and supplemental positions without disclosing the defender's primary positions. ITVs should be employed in mass (in at least platoon strength) to maximize their effectiveness.

e. BFVs are used to provide TOW and 25-mm fires, but the need to keep them accessible to dismounted elements must be considered. The highly mobile BFV should be positioned to kill BMPs both from defensive positions and in counterattacks. The scheme of maneuver should enhance the standoff, maneuverability, and night fighting advantage of the BFV over the BMP.

f. In defensive operations, the commander attempts to maximize the combat power of both the BFV and dismounted elements. Dismounted infantry defensive positions are selected to--

g. Battle positions for dismounted infantry are chosen to hold, or deny, mounted and dismounted avenues of approach to key terrain. Positioning dismounted infantry on forward slopes may needlessly expose them to long-range direct and observed indirect fires. Positions well forward, to the flanks, or on reverse slopes that deny approaches to key decisive terrain avoid exposing dismounted infantry and provide cover and concealment. Dismounted infantry is best suited for close-in fighting on restrictive terrain with limited fields of fire. Dismounted infantry should be positioned so they can only be threatened inside the ranges of their antitank weapons.

h. When good infantry terrain is not available, but the terrain must be held and armor defeated, the infantry must have time to construct obstacles and strong fighting positions. This time factor must be considered in assigning on-order and subsequent battle positions to infantry. BFVs may be positioned on the forward slope, then displaced to positions on the flanks to overwatch the rear of the dismounted elements, where they can support by fire. BFVS may also be assigned separate sectors of fire. When separated from their dismounted infantry, BFVs must have routes that allow the elements to rejoin. These routes should be reconnoitered for day and night linkup.

i. Based on the TF reconnaissance and security plan, infantry provides OPs and patrols between battle positions to augment the efforts of the scouts. Infantry can be used to provide manpower for constructing obstacles, clearing fields of fire, securing obstacles, and closing lanes and gaps in obstacles. When assigning infantry additional tasks outside of their battle positions, the time to construct individual positions must be considered.

4-9. COMBAT SUPPORT

a. Fire Support.

(1) Supporting fires are planned and used--

(2) The task force commander develops the fire support concept and tasks concurrently with the scheme of maneuver. The FSO then coordinates with the engineer, mortar platoon leader, FAC, S3 Air, and aviation liaison officer to develop an initial fire plan. This plan is refined based upon input from company commanders and FSOs. The company FSO executes fires. The task force commander and FSO may orchestrate this by establishing an event-oriented scheme of fire support. For example, "When the enemy lead MRC reaches Phase Line Red, Team A will fire target AB4200; when the enemy reaches and attempts to breach the obstacle, Company C will fire target AB4400; if the enemy attempts to bypass on the left, Company D will fire FASCAM at target AB4500."

(3) If the task force is allocated field artillery priority targets, they are planned on the most dangerous enemy avenues of approach. They may be suballocated to units on these approaches. Priority targets are shifted as the battle develops. The commander also designates priority of fires, normally to the forward security force initially, then to the unit designated as the task force main effort.

b. Mobility, Countermobility, Survivability.

(1) Engineers. The commander establishes an overall priority of engineer tasks to be accomplished. Specific priorities may be further assigned to key pieces of engineer equipment. As an example, bulldozer priority may go to key tank fighting positions (survivability). While engineer squads begin work on obstacles (countermobility) and CEVs, bucket loaders, or back-hoes dig other fighting positions or clear routes between them (mobility). Priority tasks and allocation of engineer assets must support the main effort and work must begin as soon as possible.

(a) The task force may provide manpower, additional equipment, and supplies to support the engineer effort.

(b) Obstacles support the main effort in the defense. An obstacle is any obstruction that delays, canalizes, or restricts movement or maneuver. Obstacles are grouped into two categories--existing and reinforcing. Considerations in the use of obstacles are--

(c) If covered routes out of and into battle positions are not available, these may receive a priority as well. Emphasis is on improving or maintaining existing routes rather than constructing new ones. Selective cutting in forests can provide an umbrella over the routes to keep them from being seen from the air.

(d) Protective positions for infantry and dismounted TOWs are constructed using available material that will support at least 18 inches of sandbags, rock, or dirt on top. This will protect against shrapnel from air bursts, but not direct hits. Fighting positions for vehicles are constructed with both hull-down and turret-down locations. Berms are not created since the freshly dug ground can be easily detected, and berms are not effective against kinetic energy rounds. Hull-down vehicle fighting positions take about one hour to complete, depending upon the type of soil. (Turret defilade positions take about two hours to construct and a two-step hide position requires about three hours.)

(2) NBC. NBC operations in the defense concentrate on survivability. Rehearsals are conducted in full MOPP. Plans are made for employment of smoke (see Chapter 6) and to counter enemy use of smoke.

c. Air Defense Artillery. During preparation of the defense, ADA priority normally goes to units preparing positions and obstacles. Once the defensive positions are prepared, priority goes to the main CP, combat trains, and UMCP. When maneuver is required, priority shifts to the maneuvering elements. In each situation, air defense assets focus on the main air avenue of approach.

4-10. ADDITIONAL CONSIDERATIONS

a. Security.

(1) The task force must locate and destroy the enemy reconnaissance elements early. The enemy's ability to bring overwhelming force against friendly defenses is directly tied to the effectiveness of his reconnaissance elements.

(2) Forward security is positioned based on IPB. Where necessary, security elements may be strengthened by allocating additional forces to them. For example, a tank platoon with its tank thermal sight (TTS) capability and additional firepower can be attached to the TF scout platoon at night.

b. Defensive Control Measures.

(1) Fire control measures are used to help the task force commander to mass fires on the enemy while distributing them to avoid target overkill. Combined with a well-planned obstacle system, they allow the defender to fully exploit the effects of organic and supporting weapons. Techniques for controlling task force fires are--

(a) Target reference point. A TRP is an easily recognizable point on the ground, either natural or man-made, used for identifying targets and controlling direct and indirect fires (see Figure 4-3). TRPs are designated to rapidly distribute or mass fires. A TRP is designated using a standard target symbol and target number issued either by the FSO or IAW SOP. Once designated, TRPs also constitute indirect fire targets. TRPs should be placed on each major obstacle to ensure that it is covered by both direct and indirect fires. This results in the obstacle and the direct and indirect fire targets all having the same number. TRPs should be planned on likely enemy locations and obstacles. They may also be used to clearly define engagement areas or to mark engagement and disengagement ranges. Weapons will be engaging from different directions, so compass points (north, east), rather than right or left, are used when giving directions centered on a TRP.

(b) Engagement priority. Fire can be rapidly and effectively distributed by assigning each weapon or section a type of vehicle to engage first; for example, BFVs engage BMPs; tanks or ITVs engage tanks. The most dangerous targets are shot first then targets in depth.

(c) Trigger line. A fire control measure related to terrain (roads or streams), obstacles, or weapons capabilities that initiates fire when crossed by the enemy.

(d) Sector of fire. A specific area can be assigned to a unit or a weapon. Each unit should be assigned one primary sector and an on-order or secondary sector of fire. If no targets appear in its primary sector, it engages targets in its secondary sector. (See Figure 4-4.)

(e) Engagement area. Engagement areas (Figure 4-5) may be designated by the task force or company team commanders along enemy avenues of approach. They are areas in which the commander intends to destroy an enemy force with massed fires. An engagement area can be identified by prominent terrain features around the area or by a TRP at the corners of the area. The area may be divided into sectors. The commander must provide guidance on the timing necessary to initiate fires. Distances can be marked by TRPs.

(2) Maneuver control measures normally used by the battalion task force are--

c. Limited Visibility.

(1) Normally, the task force commander can expect an attacker to use limited visibility conditions to--

(2) Defending during limited visibility, especially at night, will be a normal condition. The defender must be able to rapidly modify the defense to negate the impact of limited visibility on the operation.

(3) The task force must establish signals that initiate direct and indirect fire engagements, lift and shift fires, and initiate movement.

(4) The following steps are planning considerations for limited visibility operations:

(a) Use long-range detection equipment (radar, sensors, night observation devices) on well-defined avenues of approach.

(b) Increase surveillance of obstacles, potential enemy overwatch and assault positions, and routes into them.

(c) Redeploy some units and weapons along avenues of approach that the enemy will likely use during limited visibility.

(d) Use more infantry, scouts, OPs, patrols, and armor-killer teams forward on secondary avenues of approach and between positions to detect and slow enemy infiltration.

(e) Use point obstacles and early warning devices along likely night approaches to slow the enemy and to alert defenders to enemy presence.

(f) Plan and rehearse the required movement of weapons and units and the massing of fires.

(g) Plan illumination on or behind likely engagement areas to silhouette enemy forces while leaving defenders in shadows and darkness. While illumination is not needed with thermal sights, it may be needed for dismounted infantry.

(h) Movement tonight defensive positions should begin just before dark, and the return to daylight positions should be completed before dawn.

4-11. SYNCHRONIZATION OF DEFENSIVE OPERATIONS

The success of the defense is determined by how effectively all supporting organizations are integrated into the maneuver plan. This section describes the general defensive roles, missions, and priorities of supporting organizations.

a. Maneuver. The task force commander arrays company or teamsize forces against battalion-sized avenues of approach. Against armored attacks, the defense is organized around weapon systems that can maneuver and destroy the enemy.

(1) Scout platoon. During the defense, the scout platoon's initial mission is to coordinate the battle handover of covering force units and facilitate their orderly movement through the battalion defensive sector as battle positions. Concurrently with this mission, the scouts identify the main effort of the enemy moving into the battalion task force sector. Subsequent missions include screening missions of flank avenues of approach and maintaining contact with adjacent units.

(2) Antitank. Antitank units are employed in mass during defensive operations. Antitank units add depth to the defensive fight by being positioned to the rear of the main defensive forces to cover and support by fire. The maneuver of forward company teams positioning should allow for engagement of the enemy from the flank and rear.

(3) Attack helicopters. When brigade employs an attack helicopter battalion, it is usually used to cover gaps, to attack by fire against penetrations, to provide overwatch for counterattacking forces, or to attack enemy second echelon formations.

b. Fire Support.

(1) Field artillery. Field artillery is positioned by brigade to support both the battalion close fight and brigade deep fight. Task force priority targets are planned on the most dangerous enemy avenues of approach. They are then suballocated to units on those approaches and shifted as the battle develops. Priority of fires is initially to the forward security element during battle handover; on order, it shifts to the unit designated the main effort.

* (2) Mortars. The battalion mortars should cover the most probable dismounted enemy avenue of approach or the battalion's most critical obstacle.

(3) Air Force. CAS targets are preplanned to support the full depth of the battlefield and the transition to the offense.

c. Intelligence.

(1) GSR. In the defense, GSRs are positioned well forward to participate in the early identification of enemy reconnaissance units and confirm enemy movement within NAIs and TAIs. GSRs are most effective in these roles during limited visibility. Subsequent missions include observation of flank avenues of approach and vectoring of the reserve company/team in support of a night operation mission.

(2) Other. Aviation or ground units performing reconnaissance or security missions forward of the task force also provide valuable intelligence.

d. Air Defense Artillery. ADA assets are initially positioned well forward to provide area coverage in support of the defensive preparations, the battle handover operation, and the initial enemy attack. Subsequent employment is area coverage throughout the battlefield with priority to counterattacking forces, choke points, river crossing sites, and other potential high payoff enemy air targets.

e. Mobility, Countermobility, Survivability.

(1) Engineer. Priority of engineer support is normally to survivability, countermobility, then mobility. The engineer assists initially in planning and emplacing obstacles to support its countermobility mission.

(2) NBC. NBC operations in the defense concentrate on survivability. Smoke is employed in mobility and countermobility roles.

f. Combat Service Support.

(1) Combat trains. The combat trains are as far to the rear as possible but close enough to be responsive to maneuver units. Combat trains may be required to move frequently to support defensive operations. Combat trains operations are organized to provide continuous support but not interfere with maneuver elements.

(2) Support platoon. Before defensive operations, the support platoon brings forward barrier material. During defensive operations, the support platoon's priority of support is to Class III and V.

4-12. SEQUENCE OF THE DEFENSE

A defense will often be conducted in the following sequence of events:

a. Occupation. During this phase, the scouts are usually the first to clear the proposed defensive position. They check for enemy OPs and NBC contamination. Leaders then reconnoiter and prepare their assigned areas. Security is established forward of the defense area to allow occupation of positions and preparation of obstacles without compromise. During occupations, movement is minimized to avoid enemy observation.

b. Passage of the Covering Force. The task force establishes contact with, and assists the disengagement and passage of the covering force or other security elements. (Passage of lines is discussed in Chapter 5.)

c. Defeat of Enemy Reconnaissance Infiltration, and Preparatory Fires. Consistent with security requirements, task force elements remain in defilade, hide, and prepared positions to avoid the casualties and shock associated with indirect fires. The enemy will attempt to discover the defensive scheme by reconnaissance and probing attacks of the advance guard. The enemy may also attempt to infiltrate infantry to disrupt the defense or to breach obstacles. Task force security forces must defeat these efforts using maneuver and fires.

d. Approach of the Enemy Main Attack. Task force security elements observe and report enemy approach movement. The task force commander repositions or reorients his forces to mass against the enemy's main effort. Enemy formations are engaged at maximum range by supporting fires and close air support to cause casualties, to slow and disorganize him, to cause him to button up, and to impair his communications. Obstacles are closed. Direct fire weapons are repositioned as required, or maneuvered to attack the enemy from the flank. The task force commander may initially withhold fires to allow the enemy to close into an engagement area so that at the decisive time he can concentrate fires on the enemy formation.

e. Enemy Assault. As the enemy deploys, he becomes increasingly vulnerable to obstacles. The task force uses a combination of obstacles, blocking positions, and fires to breakup the assaulting formation. Continued maneuver to enemy flanks and rear is used to destroy him and to increase the number of directions to which he must react. Some security elements may stay in forward positions to monitor enemy second-echelon movement and to direct supporting fires on these forces as well as on his artillery, air defense, supply, and command and control elements.

f. Counterattack. As the enemy assault is slowed or stopped, the task force commander will launch his counterattack (by fire or by maneuver) to complete the destruction of the enemy forces.

g. Reorganization and Consolidation. The task force must quickly reorganize to continue the defense. Attacks are made to destroy enemy remnants, casualties are evacuated, and units are shifted and reorganized to respond to losses. Ammunition and other critical items are cross-leveled and resupplied. Security and obstacles are reestablished and reports are submitted.

4-13. BATTLE HANDOVER

a. As the covering force moves to the rear, the task force commander prepares for the battle handover. The handover is the transition from the CFA battle to the MBA battle in which the MBA forces begin to engage the enemy.

b. The battle handover is an important function in a coordinated defense because it provides assistance to the CF units near the FEBA, allowing them to disengage without excessive losses so that they can reform and fight again.

c. The difficulty inherent in the battle handover arises from when, where, and how the CF gives up responsibility for the fight and the MBA task force takes over. The battle handover line and contact points on the ground must be coordinated and clearly identifiable to both forces.

d. The headquarters that establishes the CF designates the battle handover line and establishes contact points to facilitate contact between MBA units and CFA units (see Figure 4-6). MBA and CFA commanders coordinate and recommend any changes in location of the handover line to the higher commander. The handover line is shown on the operation overlay as a phase line. It is the CFA rear boundary unless otherwise stated. The handover line delineates the location where control of the battle will be passed from the CFA to the MBA commander. It is typically 2 to 4 kilometers forward of the FEBA where MBA forces can use direct fires and observed indirect fire to assist the covering force in its final delay, disengagement, withdrawal, and rearward passage of lines. The battle handover takes place at the time or event coordinated between the commanders or as directed by the senior commander. (See Chapter 5 for a full discussion of passage of lines.)

e. The task force commander defending in the MBA positions security forces between the FEBA and the handover line (see Figure 4-7). Security forces perform security operations for the MBA as part of the commander's overall surveillance, counterreconnaissance, and deception effort. Additionally, elements from the security force man the contact points forward of the handover line.

f. The security forces--

Section IV. TYPES OF DEFENSE

The battalion task force will normally defend using three basic types of defense. They are defend in sector, defend a battle position, and defend a stongpoint. Figure 4-8 summarizes the factors a commander considers in selecting a battle position versus a sector.

4-14. DEFENSE OF A SECTOR

a. A defensive sector is an area designated by boundaries that define where a unit operates and the terrain for which it is responsible. Defense in sector is the most common defense mission for the task force.

b. Sectors may be used in both the MBA and CFA. Sector boundaries never split an avenue of approach. Task force sectors are oriented on regimental avenues of approach and are used when the brigade commander wishes to allow maximum freedom of action to his task forces. Sectors are generally deeper than they are wide to permit the defending unit to fight the battle in depth and to provide sufficient space for CSS assets. A commander defending a sector is expected to defeat enemy forces within his sector, and maintain his flank security.

c. Defend in sector is the least restrictive mission. It allows the task force commander to plan and execute his defense using whatever technique is necessary to accomplish the mission. He may use sectors, battle positions, strongpoints, or a combination of measures to accomplish his mission.

d. A defense in sector requires the task force commander to--

e. If the commander cannot concentrate fires, he distributes his forces and fires using company sectors. For example, in Figure 4-9, the commander used three companies in sector because multiple avenues of approach promoted decentralization. The reserve is positioned near where it probably will be used, and the reserve force commander prepares and reconnoiters routes to on-order counterattack positions.

(1) To control his forces, the task force commander establishes coordinating points, phase lines, on-order battle positions, and contact points.

(2) The following scenario illustrates the tactics and techniques inherent in conducting a defense in sector. In Figure 4-10, the commander has established coordinating points for control along the FEBA. His intent is to destroy the enemy force forward in the MBA. As an initial step, he has established a security force consisting of a reinforced mechanized infantry company to provide early warning, conduct counterreconnaissance, and assist the rearward passage and battle handover of the covering force. The task force commander has also added phase lines, on-order positions, and contact points to facilitate his control of the battle as it progresses.

(3) As the battle develops, the security force identifies the main effort against the middle company sector. The enemy's attack is initially blunted by the company defending this sector, which causes the enemy to lose his momentum. The left flank team commander sees an opportunity to counterattack from the flank to destroy the enemy force (see Figure 4-11). Taking this initiative is within the battle framework established by the task force commander's intent. The team commander is authorized to attack if an opportunity presents itself. The team commander informs the commander of his intended action so that the task force commander can adjust elsewhere on the battlefield and preserve unity of effort. The task force commander moves to a position to see the counterattack.

(4) The commander may compensate for changes in the battle by moving the reserve positioned in depth forward to assume responsibility for the vacant sector. Following the counterattack, he may then direct the counterattack force to conduct a rearward passage and occupy positions in depth to become the reserve.

f. As depicted in Figure 4-12, the commander may choose to employ companies in battle positions. This technique restricts maneuver and complicates flank coordination by the companies, but it gives greater control of the overall defense to the task force commander. The use of on-order battle positions with the associated tasks of prepare or reconnoiter provides flexibility and depth to the defensive plan.

g. There are many combinations of techniques that the commander could use to position his forces. The examples presented here show some of the possible combinations and conditions that could exist.

(1) When the situation calls for maximum flexibility, the commander could initially designate sectors. This case applies where the terrain forward of the FEBA is relatively open while that behind the FEBA is wooded and restrictive. Referring to Figure 4-13, the battalion commander may initially employ his TOWs, tanks, and BFVs from the wood line, using hide positions until the enemy can be engaged. Dismounted infantry could cover both mounted and dismounted avenues of approach at choke points along PL BLUE where enemy tanks and BMPs lose their mobility and firepower-range advantage. As the enemy is stopped or stalled in the woods, he can be destroyed there or on the far side. Where terrain forward of the FEBA is open, only mounted elements may be needed for the security force. Dismounted elements can remain in sector preparing their positions. When the avenue of approach clearly indicates areas where the commander can concentrate the fires of more than one company, he would use battle positions. In the example in Figure 4-13, the commander has found that most enemy avenues in his sector converge forward of BPs 9, 10, and 11, and he plans to directly control that portion of the battle.

(2) When the commander can identify a piece of terrain around which the battle can pivot, he may choose to create a strongpoint. In the example in Figure 4-14, this technique is most often employed using battle positions, but it can also be used with sectors.

(3) In Figure 4-15, the task force commander has directed a forward defense using sectors and a strongpoint to the rear. He has positioned the mounted elements forward under his control and the dismounted elements in the strongpoint under the control of the task force executive officer. The mounted elements will fight in depth within the sectors initially then from battle positions in support of the strongpoint.

4-15. DEFENSE OF A BATTLE POSITION

a. A battle position is a general location and orientation of forces on the ground, from which units defend. The BP can be for units from battalion task force to platoon size. A unit assigned a battle position is within the general area of the position (see Figure 4-16). Security forces may operate well forward and to the flanks of battle positions for early detection of the enemy and for allround security. Units can maneuver in and outside of the battle position as necessary to adjust fires or to seize opportunities for offensive action in compliance with the commander's intent.

b. The commander may maneuver his elements freely within the assigned BP. When the commander maneuvers his forces outside the BP, he notifies the next higher commander and coordinates with adjacent units. Task force security, CS, and CSS assets are frequently positioned outside the battle position with approval from the headquarters assigning the battle position.

c. Based on the space available and the relative danger of nuclear and chemical attack, the commander will allocate space to subordinate elements within the general area of the battle position.

(1) In selecting a battle position for subordinate company teams, the task force commander thinks two levels down or in terms of platoon battle positions. He must provide sufficient space on each battle position to allow dispersed primary and alternate positions for antiarmor weapons. Room for limited visibility, supplementary hide positions, and locations for combat trains are also considered.

(2) The task force commander can vary the degree of maneuver of teams within the task force BP by allocating larger team BPs. BPs may also reflect positions in depth. They need not be a standard oblong shape that suggests a linear defense within the BP. Large positions are also used to increase dispersion in a nuclear and chemical environment.

4-16. DEFENSE OF A STRONGPOINT

a. The mission to create and defend a strongpoint (see Figure 4-17) implies retention of terrain with the purpose of stopping or redirecting enemy formations. Battalion strongpoints can be established in isolation when tied to restrictive terrain on their flanks or on armor high speed avenues of approach tied to defensive positions of units on the flanks of the strongpoints. A bypassed strongpoint exposes the enemy's flanks to attacks from friendly forces in and outside the strongpoint.

b. The task force pays a high cost in manpower, equipment, material, and time for the construction of a strongpoint. It takes several days of dedicated work to construct one. Strongpoints also sacrifice the inherent mobility advantage of heavy forces. Strongpoints may be on the FEBA, or in depth in the brigade MBA.

c. When a strongpoint cannot be easily bypassed, repeated dismounted assaults must be expected and repelled. The strongpoint will receive intensive artillery attacks and must be prepared with overhead cover. Defense in depth is achieved through multiple positions within the strongpoint. The strongpoint defense is not normally conducted by a tank-heavy task force because of the limitations placed on a unit's ability to maneuver. Combat vehicles committed to the strongpoint defense use multiple firing positions, while dismounted infantry uses positions tied together with trenches.

d. A task force assigned a strongpoint mission will be required to--

e. All positions within a strongpoint are mutually supporting (see Figure 4-18). Positioning must allow the massing of the fire of two or more units against an assault and prevent the enemy from isolating positions and defeating them in detail. Sectors of fire are designated to coordinate fires between positions. Avenues of approach into and around the strongpoint, which cannot be covered by forces in primary positions, must be kept under surveillance and covered by supplemental positions that are prepared in as much detail as time permits, and occupied on order.

f. In the task force strongpoint defense, security forces operate forward initially or perform economy of force mission. On return to the strongpoint, scouts may screen to the rear. In Figure 4-19, the commander has separated dismounted and BFV elements, placing dismounted infantry in restrictive terrain while BFVs occupy positions in depth. Antiarmor occupies in-depth positions to cover sectors of fire and to gain standoff range. On-order alternate and supplementary battle positions are planned throughout the strongpoint. Mortars operate in split section masked by high ground or built-up areas in the center of the strongpoint. Combat trains, with emergency resupply of Class III and V, are in defilade positions or buildings within the strongpoint. Supplies are pre-positioned near primary, alternate, and supplementary positions. The brigade is required to provide units to keep the main supply route to the field trains open.

g. In a task force defend in sector mission, the defense can be planned in depth around a strongpoint. The task force commander establishes a strongpoint formed around a small village, wooded area, or other obstacle in his sector using dismounted infantry and one company for a counterattack force. Remaining forces defend from BPs to the rear and flanks of the strongpoint and tie into the defenses of battalions on the flanks. Enemy forces moving down the avenue of approach are met with combined arms fires inside the strongpoint and long-range weapons to its flanks. Enemy forces are canalized into the engagement area formed around the strongpoint.

Section V. RESERVE OPERATIONS

When designated as a reserve for a higher headquarters, the task force may be assigned one or more of the following missions:

Given more than one mission, the task force commander develops, plans, coordinates, and prepares for execution of his contingencies based on the priority established by the higher commander.

4-17. COUNTERATTACK

a. Counterattack planning and execution is assigned by brigade to committed and reserve task forces. Normally, more than one counterattack option is planned for and rehearsed. Counterattacks may be conducted to block an impending penetration of the FEBA, to stop a force that has penetrated, to attack through forward defenses to seize terrain, or to attack enemy forces from the flank and rear.

b. Counterattacks may be conducted by fire only or by maneuver.

c. Combat power is increased by the use of surprise, flanking attacks, speed, and violent execution.

d. The counterattack must begin movement early and launch before the enemy has time to consolidate local gains. The commander must give on-order missions to his units so that they are prepared to quickly counterattack should the opportunity arise. Task forces other than the reserve may also be tasked to carry out local counterattacks. The offense fundamentals and techniques of the attack apply to all counterattacks.

e. Regardless of the type of counterattack being conducted, the following basic considerations apply:

(1) Attack one objective at a time, and weight it with all available fire support. Once committed, the counterattack becomes the main effort.

(2) Plan the battle. Determine movement times and probable LD/LCs before committing the force to the counterattack.

(3) Defeat the attacker before being attacked by subsequent echelons.

(4) Attack the enemy's flanks and rear.

(5) Attack from an unexpected direction at an unexpected time taking advantage of protection offered by terrain and limited visibility.

f. The brigade commander may designate on-order BPs from which the reserve task force can conduct counterattacks by fire. The reserve task force commander conducts a reconnaissance of those BPs and assigns his companies battle positions from which they can fire into engagement areas to stop enemy forces. Since those on-order BPs are close to forward deployed battalion BPs, or in their sectors, close coordination will be required for--

g. If an enemy force penetrates forward defenses, counterattacks by maneuver may be required to stop the enemy's attack. This type of counterattack may be conducted as a movement to contact and meeting engagement. Based on available information, the task force moves from its assembly area using an axis to the enemy's flank. Speed is essential. Movement is by traveling or traveling overwatch with companies in column until the enemy is located. Scouts move forward to make initial visual contact with the enemy. Once contact is gained, it is maintained until the counterattack begins. Scouts may then be repositioned to protect the flanks of the task force.

h. A task force counterattack to destroy enemy forces forward of the FEBA begins with the movement of company teams from the reserve assembly area along separate routes to the attack position (see Figure 4-20). At the attack position, the task force may stop long enough to organize into the company formations to be used for the attack, pick up guides from the unit through which the counterattack force will pass, and be provided updated intelligence information. The task force moves through the forward defensive positions, and begins its attack as it crosses the LD (or LD/LC).

i. The task force must coordinate direct and indirect fire control measures to protect itself against both enemy and friendly fire. Brigade may establish a restrictive fire area around the battalion's axis of advance and its objective. Fires must be planned along the axis of advance, on the objective, on the enemy force, and along the avenues of approach that could be used by enemy second-echelon units. The task force must maintain security to its flanks and rear. Recognition signals must be established by the brigade for close air support and for the task force's return to the MBA.

4-18. SPOILING ATTACK

This is a preemptive, limited objective attack aimed at preventing, disrupting, or delaying the enemy's ability to launch an attack. The objective of the spoiling attack is: the enemy force, not to secure terrain. The reserve is often used to conduct spoiling attacks so that forward units can concentrate on defensive preparations within the MBA. Spoiling attacks are normally directed against an enemy force that is preparing to conduct an attack, or that has temporarily halted to rearm, refuel, or make the transition from mounted to dismounted operations. Enemy artillery is also a prime target.

4-19. BLOCK, FIX, OR CONTAIN

The reserve may be ordered to establish a hasty BP to block, fix, or contain enemy forces within a portion of the battlefield. This action may be necessary to blunt a penetration while other forces maneuver against the flanks or rear of the penetrating enemy force. An enemy force may be held in one area of the battlefield while he is defeated in another.

4-20. REINFORCE

Reserve forces may be committed to reinforce units that have sustained heavy losses or to build up stronger defenses in critical areas of the battlefield. Considerations must be given to how they will be integrated into the defensive scheme, command and control arrangements, and where they will be positioned. The techniques used to reinforce are similar to those used during a relief in place (see Chapter 5).

4-21. REAR OPERATIONS

The reserve battalion may operate as a division combined arms tactical combat force and be given a rear operations mission. The task force must not allow itself to become so dispersed that it cannot mass for other reserve missions. Nevertheless, the task force normally uses dispersed company positions, which both reduces the task force signature on the battlefield and helps spread its companies for the accomplishment of the rear operation. The task force completes intelligence preparation of the rear area for probable enemy avenues of approach and for likely landing zones and drop zones. It positions forces at the locations to interdict the rear area threat. Based on the IPB, location of CS and CSS elements within the brigade rear area, and their own dispositions, the task force assigns areas of responsibility to its companies or teams. Task forces are responsible for their own security within assigned areas. The task force also coordinates with CS and CSS base clusters for their defense, to include--

Section VI. OTHER DEFENSIVE OPERATIONS AND TECHNIQUES

This section describes counterreconnaissance operations common to all types of defense. It also describes several defensive techniques that are METT-T specific.

4-22. COUNTERRECONNAISSANCE OPERATIONS

a. Enemy reconnaissance operations will begin well ahead of any planned tactical operation. The task force must prevent the enemy from seeing its preparations. Enemy reconnaissance elements will conduct mounted and dismounted patrols to define positions, identify units, and detect friendly activities. His patrols will be small, move with stealth, and use concealment to observe friendly forces. These elements must be detected and denied information, or destroyed before they can report their observations. The task force's countersurveillance operations are integrated into the brigade plan to counter the enemy reconnaissance and surveillance efforts. In addition to patrols, this plan includes aerial surveillance, GSR, signals collection, indirect fires, and, if necessary, direct fires.

b. Counterreconnaissance needs to be planned so as to use all assets available to detect the enemy reconnaissance elements early. The following tasks have to be performed to ensure that this gets done:

(1) Specify the security force mission. Screen, in addition to preventing direct observation by the enemy, implies longrange observation of enemy avenues of approach to provide early warning and detection, and neutralization or destruction of enemy reconnaissance elements. The method and means to accomplish this should be specified.

(2) Provide sufficient assets. At least a screening force is needed to detect the enemy's approach and defeat the enemy's reconnaissance efforts. A forward security force can be established to provide greater resistance and deception, if the terrain allows.

(3) Establish security early and well forward. In coordination with covering force operations, the task force security element should be in place before the company teams move into their battle positions and before work on obstacles begins. The security force must be far enough forward to prevent enemy observation of defensive preparations.

(4) Put security in the right place; ensure complete coverage. Based on terrain and threat analysis, the S2 templates likely enemy reconnaissance objectives and routes and recommends the general location of the security force to the S3; the commander approves the plan. The security force commander adjusts the plan to the ground situation and specifies exact locations for each OP. This ensures long-range observation and complete, overlapping coverage of the task force sector; adjustments are reported to the TOC. During good visibility, OPs are normally established along high ground with patrolling, as necessary, between OPs. During limited visibility, positions can be adjusted to ensure covering the areas between positions. More OPs placed closer together with almost continuous patrolling between them are required. Day positions are reoccupied before BMNT. It is important to tie in with the security forces of adjacent task forces. The battalion should coordinate contact points with leaders meeting on the ground.

c. The S2 supervises the planning and establishes reporting procedures. As reconnaissance elements are detected, their activity and equipment must be reported. The S2 will use the information in developing his picture of the enemy.

d. The countering of enemy ground reconnaissance activities is a crucial task in the defense and is accomplished primarily through active measures. Considerations for integrating counterreconnaissance assets into the task force plan are as follows:

(1) Scouts. The primary counterreconnaissance asset of the task force. Most often used to provide a framework for the integration of other assets.

(2) GSR. Usually limited to open terrain and best used to cover open, high-speed avenues of approach where early detection is critical. GSR can also be used to monitor defiles, detect enemy reconnaissance elements, vector patrols, and assist in withdrawals. The effectiveness of GSR is improved by using overlapping sectors, the "flicker" on-off technique to avoid detection, and a well-enforced sleep plan to ensure that GSR operators are alert. GSR positions should be reconnoitered during daylight and occupied just before dark. Targets can be generally identified at 10 kilometers or less, movement can be detected at much greater ranges. Therefore, GSR can also be used in good visibility to support the long-range visual effort of the scouts. Because of their long range, GSRS can often support the security mission without being placed on the screen line. GSR NCOs are technical experts on the capabilities of their systems and should be included in the planning process.

(3) TOW/ITV. These elements can be used to occupy OPs and destroy enemy reconnaissance vehicles. TOW/ITV squads should be used to cover open terrain to take advantage of their long-range capability. However, the thermal sights of the ITV cannot be used continuously because of battery limitations. The crew is also smaller and less familiar with security operations than a scout squad. The use of TOW/ITV squads detracts from their ability to prepare for the defense.

(4) Maneuver units (tanks and infantry). Manning OPs and patrolling are normal infantry missions. Consideration for using infantry squads must be tempered by the MBA preparation time these squads need. Each tank crew can man only one OP, and the OP should be used to cover a relatively open, high-speed avenue of approach. Tanks and rifle squads used in the security force will not be immediately available in the MBA. TF directed emplacement and monitoring of platoon early warning systems can supplement REMS, OPs, and patrols.

(5) Provide adequate command and control for security forces. All elements of the security force must be under one leader. Normally this is the scout platoon leader. If extensive reinforcement is needed, or if a greater degree of resistance is required, the mission can be given to a maneuver company commander.

(6) Plan to recover of forward security elements. Too often units underestimate the speed of an enemy attack and begin their withdrawal too late. Specific guidance on both engaging the enemy and moving is required for the security force commander. Units receiving effective enemy fires cannot reasonably be expected to move unless those fires are suppressed or obscured. Issue precise instructions that will preclude decisive engagement and plan to provide illumination, suppression, and or obscuration. Movements should be made over previously reconnoitered routes, when supporting fires are required. For withdrawal to the MBA, routes should go around friendly units if possible, rather than through them to avoid masking friendly overmatching fires. Routes, passage points, recognition signals, and timing must be coordinated between forward security elements and company teams in the MBA. Withdrawal must be planned for both day and night. If practical, full-scale rehearsals should be conducted to ensure that timing and coordination are sufficient. This is particularly important in withdrawing a sizeable security force or withdrawal over significant obstacles.

(7) Plan for subsequent reconnaissance operations. Company teams often become so involved in fighting that they do not report the information needed for the task force commander to "see the battlefield." It is often useful to have security forces remain forward and continue to observe and direct fires against enemy maneuver, overwatch, and second echelon elements. This can sometimes be accomplished by displacing elements of the security force laterally rather than pulling them back to the MBA. Another subsequent mission is to screen a vacated sector when a company team is repositioned. GSRs can be used to determine accurate ranges for indirect fires and to monitor enemy smoke to see if it actually masks vehicles or is a deception. A common secondary mission for security forces is a flank screen. In determining which flank should be screened, the primary consideration must be that flank which has the most dangerous enemy avenues of approach. If neither flank presents a special danger, the flank boundary of an allied unit or a higher level DS unit should be considered.

(8) Establish local security. Enemy reconnaissance elements and patrols will attempt to slip past forward security forces. Therefore, maneuver elements, CPs, and CS and CSS positions must establish their own local security. OPs and ambush patrols should cover obstacles, gaps between battle positions, and avenues of approach. Supporting fires should be planned around and between battle positions and on obstacles. Available night vision devices should be positioned to ensure all-round visibility. Dead space must be covered. These efforts should be coordinated through the S2 to ensure full coverage and avoid friendly force engagements. Subordinate maneuver elements should be specifically tasked to cover the areas between battle positions and to provide reaction forces as required. The S2 consolidates the reconnaissance and surveillance plan with brigade.

4-23. STAY-BEHIND/HIDE FORCES

a. The purpose of a stay-behind force is to surprise, counterattack, defeat, and confuse the enemy. The stay-behind or hide force counterattacks enemy combat forces from the rear, or attacks and or ambushes his command and control, combat support, and combat service support elements (see Figure 4-21). This mission is a high risk operation and should not be considered lightly.

b. The commander may accept risk to take advantage of terrain to hide a force in a perimeter defense until forward enemy elements have passed the unit. Similarly, units inadvertently bypassed by the enemy may capitalize on the position to use it as a tool for offensive action in the enemy rear.

c. Success of the stay-behind force is based on--

d. The stay-behind force operation is a four-phase operation:

e. Planning considerations for a stay-behind force include--

(1) A stay-behind force positioned in the MBA may participate in some fighting.

(2) A stay-behind force positioned forward of the MBA avoids detection and does not participate in the initial fight.

(3) FA should be positioned to fire in support of the force and restrictive fire control measures planned.

(4) CS and CSS assets accompanying a stay-behind force are normally only the task force mortars, combat trains, and company and or combat trains. Use of wheeled vehicles should be limited in a stay-behind force.

(5) The return routes for the stay-behind force must be the best covered and concealed routes available. Obstacles along these routes should have guarded lanes or gaps or should be scheduled for self-destruction before the stay-behind force must cross them.

(6) Rally points should be designated.

(7) The stay-behind force should plan for a breakout and linkup with its parent unit following accomplishment of its mission.

(8) Camouflage, cover, concealment, and SIGSEC must be planned in detail.

Example

In the example shown in Figure 4-22, a mechanized-infantry-heavy battalion task force hides in a covered and concealed position forward of the FEBA. This task force is in position to outflank an enemy avenue of approach or attack a likely location for enemy command and control, air defense, or trains elements, and can defend BP 8. In the brigade plan, after passage of the covering force, the stay-behind/hide force is to counterattack to Objective RED. The commander's intent is to destroy enemy command and control, air defense, and supply vehicles. Upon completion of the counterattack or on order, the task force delays to Route BILL, returns through passage point 1, and occupies assembly area JIM to reconstitute, refit, rearm, refuel, and rest. The task force maintains radio-listening silence as it crosses the FEBA. It must be in position before battle handover at PL HARRY and should not begin the attack until the covering force has passed and the enemy can be surprised. A premature attack would result in the destruction of the force. The task force commander conducts an estimate of the situation and develops the following plan:

Each team initially occupies camouflaged defensive positions. Company teams run wire into the battalion task force TOC to maintain radiolistening silence. Scouts screen the flank of the task force BP, report covering force passage and enemy approach. The covering force performs its defense or delay mission, passes lines, withdraws, and hands over the battle at PL HARRY. Task force scouts maintain the screen. The scouts report locations, types, and quantities of enemy command and control elements, ADA, and engineer vehicles.
On order, teams conduct a movement to contact, bypassing friendly obstacles if possible, and occupy BP5, BP6, and BP7 (Figure 4-23). Upon occupation, teams engage enemy forces in their respective engagement areas (GREEN, WHITE, and BLUE). Mortars and artillery fire into the engagement areas and also fire screening smoke to confuse follow-on echelons.

The task force commander maintains these positions as long as possible. On order, the teams disengage and, if pursued, delay to the march start point using battle positions 17, 16, and 15.

4-24. PERIMETER DEFENSE

a. A perimeter defense is oriented in all directions (see Figure 4-24). A task force organizes a perimeter defense to provide self-protection. A perimeter is established when the task force must hold critical terrain in areas where the defense is not tied in with adjacent units. The task force may also form a perimeter when it has been bypassed and isolated by the enemy and must defend in place. The general form of a perimeter is also used when the task force must prepare and defend from a strongpoint.

b. Any requirement to hold or protect features, such as bridges, airfields, or landing zones, from enemy observation and fire restricts the flexibility of units while in a perimeter. These restrictions and the inability to achieve depth make a perimeter defense particularly vulnerable to armor. The commander minimizes these vulnerabilities by--

c. Although time for planning varies, the sequence of establishing a perimeter is generally the same as for other defenses. A tentative perimeter line should be selected to take advantage of defensible terrain. An effort should be made to retain terrain that is key to future linkup, extraction, or breakout.

d. The perimeter line takes advantage of terrain and obstacles while ensuring that the defense will not be too thin or the perimeter too small. A battalion task force normally establishes a perimeter 2 to 4 kilometers in diameter.

e. The perimeter is divided into company sectors with boundaries and coordinating points.

f. The task force commander normally employs the security elements outside the perimeter for early warning. He may augment security with mounted or dismounted patrols and OPs provided and controlled by units on the perimeter. The security elements are positioned to observe avenues of approach. Areas that cannot be observed by stationary elements are covered by patrols and early warning devices. If the security element remains under the control of the task force commander, it must coordinate with units on the perimeter before passage into the perimeter.

g. The reserve defends a portion of the second line of defense behind the perimeter elements. The reserve must have the mobility necessary to react to enemy action in any portion of the perimeter. It is positioned to block the most dangerous avenue of approach and is assigned on-order positions on other avenues that may be critical.

h. If the perimeter is penetrated, the reserve blocks the penetration or counterattacks to restore the perimeter. After committing the reserve, the commander must reconstitute a reserve to meet other threats. This force normally comes from an unengaged unit in another portion of the perimeter. If an unengaged force is used to constitute a new reserve, sufficient forces must be retained in the vacated sector to defend that portion of the perimeter. The ability to separate BFV and dismounted element allows the commander to designate a mobile reserve in each company sector.

i. The employment of organic and attached weapons in a perimeter defense is the same as for other defense operations. Indirect fire weapons engage the enemy as far forward of the perimeter as possible. Field artillery may support the task force from within the perimeter or from another location. If within the perimeter, plans should include the use of artillery in both a direct and an indirect fire role.

j. If the task force forms the perimeter because of isolation, combat, combat support, and combat service support elements from other units come under the tactical command of the senior commander in the perimeter. They are given missions based on their support capabilities. All service support assets within the perimeter should be in a protected location from which they can provide continuous support. Their location and operation should not restrict or be restricted by the fires or movement of perimeter fire support and reserve units.

k. Resupply may have to be by air. The availability of landing and drop zones is an important consideration in selecting and organizing the position.

4-25. REVERSE SLOPE DEFENSE

a. The reverse slope defense uses the topographical crest to mask the defender from the supporting direct fire and observation of the attacker.

b. A task force rarely conducts a reverse slope defense along its entire front; however, there may be situations where subordinate units and weapons systems may be employed on the reverse slope. The task force commander may adopt a reverse slope position for elements of the battalion:

c. A reverse slope position is particularly effective when flanking fires from units on adjacent terrain features can be placed on the forward slope. However, the key to the reverse slope defense is control of the crest by fire and the proper use of obstacles, as in Figure 4-25. The result is surprise, isolation, and defeat of a manageable portion of the attacker's force.

d. The reverse slope defense can be especially effective against fast-moving mechanized forces. It establishes an engagement area for the concentration of heavy firepower into which the enemy moves directly after reaching the crest of a hill or ridgeline. The result is a surprised enemy who is engaged by weapons that are in defilade to all but his forward element, which is under heavy fire.

e. The defender uses a reverse slope to isolate the lead echelon from follow-on forces. This eliminates the direct fire from weapons in the follow-on echelon. The attacker's effective use of combined arms is disrupted, and his tanks may be unable to depress their gun tubes far enough to provide effective fires. This gives the defender opportunities for "belly shots" at enemy armor.

f. The reverse slope defense is organized according to the fundamentals that apply to all defensive positions. A reverse slope position requires good fields of fire to the crest of the hill and, if possible, to the forward slope of adjacent reverse slope positions. Fires should be placed on the crest and the reverse slope. Another factor affecting the organization of the reverse slope position is adjacent reverse slope defensive positions.

g. If the situation permits, a security element should be established on the forward slope to stop or delay the enemy, disorganize his attack, and deceive him as to the location of the defensive position. The security element should be strong enough to strip away enemy reconnaissance, begin long-range engagements, and force the enemy to deploy and assault the forward slope.

h. Observation posts must be established just forward of the topographical crest to give long-range observation over the entire front. The OPs should include forward observers from the FIST. The number and composition of the OPs should be strengthened at night.

i. Reserve or overmatching elements may be on the military crest of the next high ground to the rear if it is within supporting range.

j. Observation and fires are maintained over the forward slope as long as possible to disrupt the enemy and prevent him from massing for the assault. Disengagement time is determined by the distance the security force elements must travel to their subsequent positions.

k. Direct fire weapons on the reverse slope and next high ground to the rear withhold their fires until suitable targets appear. As the enemy crosses the crest, priority targets are initiated. Artillery and mortar fires and smoke against the topographical crest assist in the isolation of the attacker.

l. If the enemy is successful in seizing the crest, or if he makes a penetration, a counterattack may be launched to destroy him and to restore the crest.

m. Finally, the commander's estimate may lead him to organize reverse slope positioning only for selected weapons. (Figures 4-26 and 4-27 illustrate reverse slope positioning.)

4-26. URBAN AREA OPERATIONS

a. On the battlefield, the defender uses the advantage of both natural and man-made features. Urban sprawl adds strength to the defense by providing covered and concealed positions and by restricting the attacker's mobility and observation. A task force normally defends 4 to 12 city blocks, depending on the type of urban area.

b. Dismounted infantry occupies battle positions or strongpoints around which the mobile battle is fought. In restrictive urban terrain, dismounted forces may be required to find the enemy, deny him the ability to attack without being detected, and then fight the close-in battle. If a built-up area must be retained, a position defense is organized in depth and supported by strong mobile forces.

c. The urban area defense begins with mobile, combined arms forces deployed well forward of the urban area. Company teams in BPs or sectors are organized in-depth to control approaches to the urban area. Small villages and strip areas are incorporated into the defensive scheme in the same manner as other terrain features. Tanks and BFVs can operate in and around these built-up areas, concentrating their fires into engagement areas between the villages. Tanks and BFVs maneuver outside and between these areas to contribute their fires from different directions and cause the enemy to fight a nonlinear battle. The defense is anchored with dismounted infantry in BPs and strongpoints in the villages. (See Figure 4-28.)

d. The handover of the battle by the forward force must not allow the enemy to gain momentum. The restrictive nature of the urban terrain complex, obstacles, and readily available defensive positions may facilitate the handover if properly coordinated.

e. Restrictive or compartmented areas within urban terrain may provide the enemy with covered or concealed infiltration routes into the defensive position. Responsibility for all blocks, rooftops, and underground rail and sewer systems must be clearly defined.

f. Urban areas usually sit astride or dominate high-speed avenues of approach through or around the urban area. If urban areas cannot be bypassed easily, they may reduce the momentum of the enemy's attack. (For a detailed discussion on defensive operations in urbanized terrain, see FM 90-10.)