Infantry Drills

FM 3-21.8 – Chapter 1 – Section VII – Combat Power

section vII — combat power

1-180.  Combat power is the ability of a unit to fight. To generate combat power, Army forces at all levels conduct operations.  An operation is a military action or carrying out of a mission (FM 1-02). Leaders at the operational level of war develop operations in response to receiving strategic guidance. These operations consist of numerous component operations, tasks, and actions. Within these operations, leaders at the operational level assign their subordinate’s missions. These subordinates, in turn, develop operations to accomplish their mission. They then assign the mission to subordinates as part of their overall operations. This chain of events continues until the Infantry platoon and squad receives its mission. Leaders at all levels use many tools to develop and conduct operations. Two of the most important tools are—

– The four critical functions.

– Full spectrum operations doctrine.

Four Critical Functions

1-181.  Most combat actions follow the sequence of find, fix, finish, and follow-through. First, the unit must find the enemy and make contact. Second, they fix the enemy with direct and indirect fires. Third, the unit must finish the enemy with fire and movement directed towards a vulnerable point in order to fight through to defeat, destroy, or capture the enemy. Fourth, the unit must follow-through with consolidation, reorganization, and preparing to continue the mission or receive a new mission.

1.    Find the Enemy

1-182.  At the individual, crew, and squad and platoon levels, finding the enemy directly relates to target acquisition. Target acquisition is the process of searching for the enemy and detecting his presence; determining his actual location and informing others; and confirming the identity of the enemy (not a friend or noncombatant). The most common method of target acquisition is assigning sectors to subordinates. Once assigned, Soldiers use search techniques within their sectors to detect potential targets.

1-183.  There are many different sources for finding the enemy. They include:

– Other Soldiers, crews, squads and platoons.

– Forward observers.

– Reconnaissance elements (scouts, reconnaissance units, cavalry, and long-range surveillance units).

– Aviation assets such as the OH58D.

– Unmanned aircraft system(s) (UAS).

– Lightweight Counter-mortar Radar (LCMR).

– Special Forces.

1-184.  Finding the enemy consists of physically locating him and determining his disposition. Enemy strength, composition, capabilities, probable COA, and exploitable vulnerabilities are important determinations made in the location process. The leader seeks to develop the situation as much as possible out of contact with the enemy. Once in contact, he fights for the information he needs to make decisions.

Plan and Prepare

1-185.  Finding the enemy begins long before the unit moves across the line of departure (offense) or occupies its battle position (defense). During planning, the leader’s METT-TC analysis is essential to developing the clearest picture of where the enemy is located, the probable COA, and the most dangerous COA. When there is little information about the enemy, a detailed analysis of terrain will assist the leader in predicting enemy actions. During preparation, the leader sends out his reconnaissance or submits his information requirements to higher headquarters to develop the enemy picture as thoroughly as possible.


1-186.  During execution, the unit’s first priority is to find the enemy before the enemy finds them. This involves employing good cover, concealment, camouflage, and deception while denying the enemy the same. During tactical movement, the unit must have an observation plan that covers their entire area of influence. Additionally, the leader takes measures to detect enemies in the unit’s security zone.

1-187.  Once found, the leader has a decision to make. In the offense, the leader must determine if he has enough forces to fix the enemy or if he should pass the enemy position off to a separate fixing force. In the defense, he must determine if he has enough forces to disrupt the enemy or if he should pass the enemy force off to a separate fixing force.

2.    Fix

1-188.  Immediately after finding the enemy, the leader has to fix the enemy in place. Fixing the enemy holds him in position. When the enemy is fixed, the leader can maneuver to the enemy’s vulnerable point without the fear of being attacked in an exposed flank, or of more enemy forces reinforcing. Fixing the enemy normally consists of one of the following tactical mission tasks: support by fire, attack by fire, suppress, destroy, or block. An enemy that is fixed is affected physically and or psychologically. The means to achieve this effect—lethal, nonlethal, and combinations thereof—are endless.

1-189.  Fixing the enemy is accomplished through isolation. “Isolate” means cutting the adversary off from the functions necessary to be effective. Isolation has both an external aspect of cutting off outside support and information, and an internal aspect of cutting off mutual support. Isolating the adversary also includes precluding any break in contact.

1-190.  External isolation stops any of the fixed enemy force from leaving the engagement while preventing any other enemy force from reinforcing the fixed force. Actions outside of the objective area prevent enemy forces from entering the engagement. Internal isolation occurs by achieving fire superiority that prevents the enemy from repositioning and interfering with friendly maneuver elements.

1-191.  Isolating the objective is a key factor in facilitating the assault and preventing casualties. Isolating the objective also involves seizing terrain that dominates the area so the enemy cannot supply, reinforce, or withdraw its defenders. Infantry platoons and squads may perform this function as a shaping element for a company operation, or it may assign subordinates this function within its own organization. In certain situations, the squads or platoon may isolate an objective or an area for special operations forces. Depending on the tactical situation, Infantry platoons may use infiltration to isolate the objective.

1-192.  The enemy is fixed when his movement is stopped, his weapons suppressed, and his ability to effectively respond disrupted. Once fixed, the leader has a decision to make. In the offense, the leader must determine if he has enough forces to assault the enemy, or if he needs to request a separate assault element from the controlling headquarters. In the defense, he must determine if he has enough forces to counterattack, or if he needs to request a separate counterattack force from the controlling headquarters.

3.    Finish

1-193.  After finding and fixing the enemy, the leader finishes the fight. In the offense, this is known as the assault; in the defense, this is known as the counterattack. Finishing the enemy normally consists of one of the following tactical mission tasks: clear, seize, or destroy. It is extremely important that leaders understand the necessity to “have something left” when finishing the enemy and for the next step—follow- through. Failure to have enough combat power at the decisive point or during consolidation puts the unit at risk to counterattack. The fight is finished when the enemy—

– No longer has the physical ability to fight (meaning he is destroyed).

– Has determined physical destruction is imminent.

– No longer believes he can resist (meaning he is in shock).

4.    Follow -Through

1-194.  Follow-through involves those actions that enable the unit to transition from close combat to continuing the mission. It includes conducting consolidation and reorganization and exploiting success. Transitioning the unit from the violence of close combat back to a state of high readiness is difficult. Units are most vulnerable at the conclusion of close combat, and decisive leadership is absolutely essential to make the transition. Continuing the attack or counterattacking may be a deliberate phase of the operation (a “be-prepared-to” or “on-order” mission). It may also be a decision made by the controlling commander based on a window of opportunity.

Doctrinal Hierarchy of Operations

1-195.  Figure 1-14 shows the doctrinal hierarchy and the relationship between the types and subordinate forms of operations. While an operation’s predominant characteristic labels it as an offensive, defensive, stability, or civil support operation, different units involved in that operation may be conducting different types and subordinate forms of operations. These units often transition rapidly from one type or subordinate form to another. While positioning his forces for maximum effectiveness, the commander rapidly shifts from one type or form of operation to another to continually keep the enemy off balance. Flexibility in transitioning contributes to a successful operation.

1-196.  Infantry platoons and squads conduct all the types of operations listed in the doctrinal hierarchy. However, the Infantry platoon and squad will almost always conduct these operations and their subordinate forms and types as part of a larger unit. In fact, many of these types of operations are only conducted at the battalion, brigade, or division level. Only the types of operations applicable to Infantry platoons and squads are further covered in this manual.

Figure 1-14. Doctrinal hierarchy of operations.

Offensive Operations

1-197.  Offensive operations aim to destroy or defeat an enemy. Their purpose is to impose U.S. will on the enemy and achieve decisive victory (FM 3-0, Operations). Dominance of the offense is a basic tenet of U.S. Army operations doctrine. While the defense is the stronger form of military action, the offense is the decisive form. Tactical considerations may call for Army forces to execute defensive operations for a period of time. However, leaders are constantly looking for ways to shift to the offense. Offensive operations do not exist in a vacuum—they exist side by side with defense, and tactical enabling operations. Leaders analyze the mission two levels up to determine how their unit’s mission nests within the overall concept. For example, an Infantry platoon leader would analyze company and battalion missions.

1-198.  Effective offensive operations require accurate intelligence on enemy forces, weather, and terrain. Leaders then maneuver their forces to advantageous positions before contact. Contact with enemy forces before the decisive action is deliberate and designed to shape the optimum situation for the decisive action. The decisive action is sudden and violent, capitalizing on subordinate initiative. Infantry platoon and squad leaders therefore execute offensive operations and attack with surprise, concentration, tempo, and audacity.

1-199.  There is a subtle difference between attacking and conducting an attack. Attacking in everyday usage generally means the close combat action of fire and movement on an enemy or position. Attacking occurs frequently on the battlefield in all types of operations. Conducting an attack is one of the four types of offensive operations with specific doctrine meanings and requirements.

Offensive Purposes

1-200.  How a unit conducts its offensive operations is determined by the mission’s purpose and overall intent. There are four general purposes for the offense: throw the enemy off balance; overwhelm the enemy’s capabilities; disrupt the enemy’s defense; and ensure their defeat or destruction. In practice, each of these purposes has orientation on both the enemy force and the terrain. The labels merely describe the dominant characteristic of the operation.


1-201.  Leaders employ enemy-oriented attacks to destroy enemy formations and their capabilities. Destruction results in an enemy unit (Soldiers and their equipment) that is no longer able to fight. Not everything has to be destroyed for the force-oriented attack offense to be successful. It is usually enough to focus on an enemy capability or unit cohesion. These attacks are best employed against an enemy vulnerability. Once destruction occurs, a window of opportunity opens. It is up to the leader to take advantage of an unbalanced enemy through local and general exploitations and pursuit.


1-202.  Leaders employ terrain-oriented attacks to seize control of terrain or facilities. Units conducting terrain-oriented attacks have less freedom of action to take advantage of a window of opportunity. The unit’s first priority is the terrain or facility. Exploiting an enemy vulnerability can occur only when the security of the terrain or facility is no longer in question.

Tactical Enabling and Infantry Platoon Actions

1-203.  Although friendly forces always remain enemy focused, there are many actions friendly forces conduct that are offensive in nature and are designed to shape or sustain other operations. Leaders employ tactical enabling operations to support the overall purpose of an operation.

Types of Offensive Operations

1-204.  Types of offensive operations are described by the context surrounding an operation (terrain or force oriented). At the platoon and squad level, these offensive operations are basically planned, prepared for, and executed the same. The four types of offensive operations include:

(1)     Movement to Contact – undertaken to gain or regain contact with the enemy (force-oriented).

(2)     Attack – undertaken to achieve a decisive outcome (terrain-oriented or force-oriented).

(3)     Exploitation – undertaken to take advantage of a successful attack (force-oriented).

(4)     Pursuit – undertaken to destroy an escaping enemy (force-oriented).

1-205.  This order of offensive operations is deliberate because they are listed in order of their normal occurrence. Generally, leaders conduct a movement to contact to find the enemy. When the leader has enough information about the enemy to be successful, he conducts an attack. Following a successful attack, the leader takes advantage of the enemy’s disorganization and exploits the attack’s success. After exploiting his success, the leader executes a pursuit to catch or cut off a fleeing enemy to complete its destruction. Although Infantry platoons and squads participate in exploit and pursuit operations, they do not plan them.

Defensive Operations

1-206.  Defensive operations defeat an enemy attack, buy time, economize forces, or develop conditions favorable for offensive operations. Defensive operations alone normally cannot achieve a decision. Their overarching purpose is to create conditions for a counteroffensive that allows Army forces to regain the initiative (FM 1-02). Defensive operations do not exist in a vacuum—they exist side by side with offense, tactical enabling operations, and Infantry platoon actions. Leaders analyze the mission two levels up to determine how their unit’s mission nests within the overall concept.

1-207.   The principles of tactical maneuver also apply to the defense. To be decisive, defensive tactics must have both ingredients. Ensuring mobility remains a part of the defense is one of the leader’s greatest challenges. While it is true that defending forces await the attacker’s blow and defeat the attack by successfully deflecting it, this does not mean that defending is a passive activity. Leaders always look for ways to integrate movement into their defensive activities.

1-208.  During the conduct of operations, regardless of type, friendly forces make many transitions requiring the unit to stop and restart movement. Infantry platoons and squads that are not moving are defending. Units that stop moving (attacking), immediately transition to defending. This transition is rapid and should be second nature to all Soldiers and their units. This is particularly relevant at the Infantry platoon and squad levels where the tactical situation can quickly shift to one where the unit is outnumbered and fighting for its survival.

Defensive Purposes

1-209.  How a unit establishes its defenses is determined by the mission’s purpose and intent. There are four general purposes for conducting a defense: defeat an attacking enemy; economize friendly forces in one area so they can be concentrated in another area; buy time; and develop conditions favorable for resuming offensive operations. In practice, each of these stated purposes for conducting a defense is considered in all defenses; the categories just describe the dominant purpose. Infantry platoons and squads can also be tasked to defend specific locations such as key terrain or facilities.

Defeat an Attacking Enemy and Develop Conditions for Offensive Operations

1-210.  Defenses are designed to defeat enemy attack while preserving friendly forces. Defeating the enemy’s attack requires him to transition to his own defensive actions. While this occurs, a window of opportunity for friendly forces may also occur. It is up to the leader to take advantage of an unbalanced enemy through local and general counterattacks.

Economy of Force to Concentrate in Another Area

1-211.  Commanders seldom have all the combat forces they desire to conduct operations without accepting risk. Economy of force is defined as allocating minimum essential combat power to secondary efforts (FM 1-02). It requires accepting prudent risk in selected areas to achieve superiority—overwhelming effects—in the decisive operation. As a result, commanders arrange forces in space and time to create favorable conditions for a mobile defense and offensive operations in other areas.

Buy Time

1-212.  Defenses to preserve friendly combat power are designed to protect the friendly force and prevent the destruction of key friendly assets. There are times when the unit establishes defenses to protect itself. Although friendly forces always remain enemy focused, there are many actions friendly forces conduct to sustain the unit. These sustaining actions typically require the unit to establish a defensive posture while the activity is conducted. Examples include: consolidation and reorganization, resupply/LOGPAC, pickup zone/landing zone, and CASEVAC/MEDEVAC. This type of defense can also be associated with assembly area activities, establishing lodgments for building up combat power, and facing a numerically-superior enemy force.

Develop Conditions Favorable for Resuming Offensive Operations

1-213.  The enemy may have the advantage over friendly forces in areas such as combat power or position.  This often occurs during forced entry operations where friendly forces defend in order to build up combat power.

Key Terrain or Facilities

1-214.  Defenses for denying enemy access to an area are designed to protect specific location, key terrain, or facilities. Infantry platoons can be assigned missions to defend sites that range from hill tops—to key infrastructure—to religious sites. Because the defense is terrain oriented, leaders have less freedom of action when it comes to taking advantage of a window of opportunity. The unit’s first priority is the terrain or facility. Exploiting an enemy vulnerability can occur only when the security of the terrain or facility is no longer in question.

Types of Defensive Operations

1-215.  Defensive operations fall into one of the following three categories:

(1)     Area defense – focuses on retaining terrain for a specified period of time (terrain-oriented).

(2)     Mobile defense – stops an enemy attack with a fixing force and destroys it with a strike
force (division level and higher operations [force-oriented]).

(3)     Retrograde – a type of defensive operation that involves an organized movement away from
the enemy. The three types of retrograde operations are: delay; withdrawal; and retirement.

Area Defense

1-216.  The area defense is the most common defensive operation undertaken at the tactical level (brigade and below). This is discussed in Chapter 9.

Mobile Defense

1-217.  The mobile defense is usually a corps-level operation. A mobile defense has three categories of forces: a fixing force, a strike force, or a reserve force. The decisive operation of a mobile defense is the strike force. Those units designated as the fixing force are essentially performing an area defense. Units designated as the strike force are essentially performing an attack. (For more information on the mobile defense, see FM 3-90, Tactics.)


1-218.  The retrograde is a technique used by higher-level commanders to maintain or break contact with the enemy.  This is done as part of a larger scheme of maneuver to create conditions to regain the initiative and defeat the enemy. Retrogrades improve the current situation or prevent a situation from deteriorating. These operations are a means to an end; not an end in itself. The Infantry platoon’s fight in the higher commander’s retrograde operation uses one of two techniques: fighting the enemy, or moving to the new location. Leaders must be aware of the potentially catastrophic impact a retrograde has on friendly troop’s morale. The retrograde is the defensive counterpart to an offensive exploitation or pursuit. There are three techniques used to retrograde:

– Delay – trades space for time (attempting to slow the enemy’s momentum).

– Withdrawal – trades time for space (breaking contact as far from the enemy as possible).

– Retirement – movement that is not in contact with the enemy.

Stability Operations

1-219.  Stability operations encompass a range of actions that shape the political environment and respond to developing crises. This section provides an introductory discussion of stability operations (FM 3‑0 and FM 3‑07, Stability Operations and Support Operations).

1-220.  Stability operations usually occur in conjunction with offensive and defensive operations. These operations are diverse, continuous, and often long‑term. They may include both developmental and coercive actions. Developmental actions are aimed at enhancing a government’s willingness and ability to care for its people, or simply providing humanitarian relief following a natural disaster. Coercive military actions involve the application of limited, carefully prescribed force, or the threat of force to achieve specific objectives. Stability operations are usually noncontiguous, and are often time and human intensive. Army elements might be tasked to conduct stability operations in a complex, dynamic, and often asymmetric environment to accomplish one or more of the following purposes:

– Deter or thwart aggression.

– Reassure allies, friendly governments, agencies, or groups.

– Provide encouragement and support for a weak or faltering government.

– Stabilize an area with a restless or openly hostile population.

– Maintain or restore order.

– Satisfy treaty obligations or enforce national or international agreements and policies.

– Provide humanitarian relief outside the continental United States and its territories.

Civil Support Operations

1-221.  The overall purpose of civil support operations is to meet the immediate needs of designated groups, for a limited time, until civil authorities can accomplish these tasks without Army assistance. Civil support operations are a subset of Homeland Security. Operations support the nation’s homeland defense (offensive and defensive), and are only conducted inside the U.S. and its territories.

1-222.  During civil support operations, Infantry platoons and squads help provide essential services, assets, or specialized resources to help civil authorities deal with situations beyond their capabilities. The adversary is often disease, hunger, or the consequences of disaster. Civil support operations for the Infantry platoon and squad may include assisting civilians in extinguishing forest fires, in rescue and recovery efforts after floods or other natural disasters, or in supporting security operations before, during, or after terrorist attacks. Platoons and squads must maintain the capacity to conduct offensive, defensive, and tactical enabling operations during the conduct of civil support operations.

Tactical Enabling Operations

1-223.  Tactical enabling operations support the larger unit’s effort to accomplish its mission. They always play a supporting role as part of one of the full spectrum operations. The effective planning, preparation, execution, and assessment of tactical enabling operations mirror that of traditional offense and defense operations.

1-224.  There are six types of tactical enabling operations: reconnaissance; security; troop movement; relief in place; passage of lines; and combined arms breach.


1-225.  Reconnaissance operations are undertaken to obtain (by visual observation or other detection methods) information about the activities and resources of an enemy or potential enemy. They are designed to secure data concerning the meteorological, hydrographical, or geographical characteristics and the indigenous population of a particular area (FM 1-02). The four forms of reconnaissance are route; zone; area; and reconnaissance in force.

1-226.  Reconnaissance is performed before, during, and after other operations to provide information to the leader or higher commander for situational understanding. Reconnaissance identifies terrain characteristics, enemy and friendly obstacles to movement, and the disposition of enemy forces and civilian population; all of which enable the leader’s movement and maneuver. Leaders also use reconnaissance prior to unit movements and occupation of assembly areas. It is critical to protect the force and preserve combat power. It also keeps the force free from contact as long as possible so it can concentrate on its decisive operation.


1-227.  Security operations are undertaken by the commander to provide early and accurate warning of enemy operations, to provide the force being protected with time and maneuver space within which to react to the enemy, and to develop the situation to allow the commander to effectively use the protected force. The five forms of security are cover, guard, screen, area, and local.

1-228.  The ultimate goal of security operations is to protect the force from surprise and reduce the unknowns in any situation. Leaders employ security to the front, flanks, or rear of their force. The main difference between security and reconnaissance operations is that security operations orient on the force or facility being protected, while reconnaissance is enemy and terrain oriented. Security operations are shaping operations.

Troop Movement

1-229.  Troop movement is the movement of troops from one place to another by any available means (FM 1-02). Troops move by foot, motor, rail, water, and air. There are three types of troop movement, with corresponding levels of security based on the presence of the enemy: administrative movement; road march; and approach march. (See Chapter 4.)

1-230.  Successful movement places troops and equipment at their destination at the proper time, ready for combat. Commanders use various forms of troop movement to concentrate and disperse their forces for both decisive and shaping operations. Therefore, leaders and their Soldiers need to be familiar with all of the methods and types of troop movements and their roles within them.

Relief in Place

1-231.  A relief in place (RIP) is an operation in which all or part of a unit is replaced in an area by the incoming unit. The responsibilities of the replaced elements for the mission and the assigned zone of operations are transferred to the incoming unit. The incoming unit continues the operation as ordered (FM 1-02).

Passage of Lines

1-232.  A passage of lines is a tactical enabling operation in which one unit moves through another unit’s positions with the intent of moving into or out of enemy contact (FM 1-02). Infantry platoons and squads perform roles as either the moving or stationary unit.

Combined Arms Breach

1-233.  Combined arms breach operations are conducted to allow maneuver, despite the presence of obstacles. Breaching is a synchronized combined arms operation under the control of the maneuver commander. Breaching operations begin when friendly forces detect an obstacle and begin to apply the breaching fundamentals.  However, they end when battle handover has occurred between follow-on forces and the unit conducting the breaching operation (FM 1-02).

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