Mobility, Countermobility, and Survivability. Mobility in defense means the ability to reposition forces, including unit displacement and the commitment of reserve forces. The company commander’s priorities may specify that some routes be improved to support such operations. Countermobility (obstacles) limits the maneuver of enemy forces and enhances the effectiveness of the defender’s direct and indirect fires. Survivability focuses on protecting friendly forces from the effect of enemy weapons systems.
Air Defense. The focus of an air defense plan is on likely air avenues of approach for enemy fixed-wing aircraft, helicopters, and unmanned aerial vehicles, which may not correspond with the enemy’s ground avenues of approach. A platoon leader is not likely to emplace air defense assets; however, he must be aware that higher headquarters may employ air defense assets near his defensive position.
Combat Service Support. In addition to the CSS functions required for all, the platoon leader’s mission analysis (or guidance) may reveal that the unit’s ammunition needs during an operation could exceed its basic load. This requires the platoon to establish ammunition caches. These caches, which may be positioned at alternate or subsequent positions, should be dug in and security provided by active or passive means (such as guarded or observed) or passive measures employed to indicate when and if the cache is tampered with.
Intelligence. Gaining information about the enemy is critical in defense. Continuing intelligence updates as well as constant reconnaissance of the area afford the infantry leader the information needed to constantly improve the unit’s position.
Command and Control. Command and control refers to the process of directing, coordinating, and controlling a unit to accomplish a mission. Having effective communication to higher and supporting units is an essential BOS.
ENGAGEMENT AREA DEVELOPMENT
The engagement area (EA) is the place where the unit leader intends to destroy an enemy force using the massed fires of all available weapons. The success of any engagement depends on how effectively the leader can integrate the obstacle and indirect-fire plans with his direct-fire plan in the EA to achieve the unit’s purpose. Despite its complexity, EA development resembles a drill. The leader and his subordinate leaders use a standardized set of procedures. Beginning with an evaluation of the factors of METT-TC, the development process covers these steps:
1.Identify likely enemy avenues of approach.
2.Identify the enemy scheme of maneuver.
3.Determine where to kill the enemy.
4.Emplace weapons systems.
5.Plan and integrate obstacles.
6.Plan and integrate indirect fires.
7.Conduct an EA rehearsal.
Identify Likely Enemy Avenues of Approach
The infantry leader conducts an initial reconnaissance of the enemy’s probable avenue of approach into the sector or EA. He confirms key terrain identified by the company commander, including locations that afford positional advantage over the enemy and natural obstacles and choke points that restrict forward movement. The platoon leader determines which avenues will afford cover and concealment for the enemy while allowing him to maintain his tempo. The leader also evaluates lateral mobility corridors (routes) that adjoin each avenue of approach.
Identify the Enemy Scheme of Maneuver
The leader greatly enhances his planning by gaining information early. He attempts to receive answers (from higher headquarters) about the enemy’s purpose, direction, terrain orientation, mission, objectives, attack structure, recon assets, expected rate of movement, and response to friendly actions.
Determine Where to Kill the Enemy. As part of his troop-leading procedures, the infantry leader must determine where he will mass combat power on the enemy to accomplish his purpose. This decision is tied to his assessment of how the enemy will fight into the platoon’s EA. Normally this entry point is marked by a prominent reference point (RP) that all platoon elements can engage with their direct-fire weapons. This allows the commander to identify where the platoon will engage enemy forces through the depth of the company EA. In addition, the leader wilclass="underline"
•Select target reference points (TRPs) that match the enemy’s scheme of maneuver, allowing the platoon (or company) to identify fire support adjustment points.
•Identify and record the exact location of each TRP.
•Determine how many weapons systems can focus fires on each TRP to achieve the desired purpose.
•Determine which squad(s) can mass fires on each TRP.
•Begin development of a direct-fire plan that focuses at each TRP.
Note: In marking TRPs, use thermal sights to ensure visibility at the appropriate range under varying conditions, including daylight and limited visibility.
Emplace Weapons Systems
To position weapons effectively, leaders must know the characteristics, capabilities, and limitations of the weapons as well as the effects of terrain and the tactics used by the enemy. Platoon leaders should position weapons where they have protection, where they can avoid detection, and where they can surprise the enemy with accurate, lethal fires. In order to place them, the platoon leader must know where he wants to destroy the enemy and what effect he wants the weapons to achieve. He should also consider:
•Selecting tentative squad defensive positions.
•Conducting a leader’s reconnaissance of the tentative defensive positions.
•Walking the EA to confirm that the selected positions are tactically advantageous.
•Confirming and marking the selected defensive positions.
•Developing a direct-fire plan that accomplishes the platoon’s purpose.
•Ensuring the defensive positions do not conflict with those of adjacent units and are effectively tied in with adjacent positions.
•Selecting primary, alternate, and supplementary fighting positions to achieve the desired effect for each TRP.
•Ensuring the squad leaders position weapons systems so the required numbers of weapons or squads effectively cover each TRP.
•Inspecting all positions.
Note: When possible, select fighting and crew-served weapon positions while moving in the EA. Using the enemy’s perspective enables the platoon leader to assess survivability of the positions.
Plan and Integrate Obstacles
To be successful in the defense, the platoon leader will integrate tactical obstacles with the direct-fire plan, taking into account the intent of each obstacle. Obstacles disrupt, turn, or fix the enemy. A combat platoon must have a clear task and purpose in order to properly emplace a tactical obstacle. Once the tactical obstacle has been emplaced, the platoon leader must report its location and any gaps in the obstacle to the company commander.
There are two types of obstacles: existing and reinforcing. Existing obstacles are those natural or cultural restrictions to movement that are part of the terrain when battle planning begins, such as slopes, gullies, rivers, swamps, trees, or built-up areas. Reinforcing obstacles are those specifically constructed, emplaced, or detonated to tie together, strengthen, and extend existing obstacles. Reinforcing obstacles include road craters, abatis, ditches, log hurdles, cribs, rubble, or wire entanglements.
Wire Obstacles. Wire is classified by its use and location.
Tactical. Tactical wire is sited parallel to and along the friendly side of the final protective line (FPL). It breaks up the enemy attack and holds the enemy where its troops can be killed or wounded by automatic rifle fire, Claymores, hand grenades, and machine-gun fire.