--Reverse Slope Defense

3-155. An alternative to defending on the forward slope of a hill or a ridge is to defend on a reverse slope. (See figure 3-16.) In such a defense, the Infantry platoon is deployed on terrain that is masked from enemy direct fire and ground observation by the crest of a hill. Although some units and weapons might be positioned on the forward slope, the crest, or the counter-slope (a forward slope of a hill to the rear of a reverse slope), most forces are on the reverse slope. The key to this defense is control the crest by direct fire.

Platoon defense on a reverse slope

Figure 3-16. Platoon defense on a reverse slope

FUNDAMENTALS

3-156. Planning fundamentals to a defense on a reverse slope include ─

  • Positioning forward squads so they block enemy approaches and exploit existing obstacles. Plans should-
    • Permit surprise fire on the crest and on the approaches around the crest.
    • Have rear and overhead cover to protect friendly Soldiers from fratricide while in forward fighting positions.
  • Positioning observation posts, on the crest or the forward slope of the defended hill. Plans should-
    • Increase observation posts and patrols to prevent infiltration at night.
    • Consider attaching medium machine guns to observation posts.
  • Positioning the squad in-depth or reserve where it can provide the most flexibility, support the forward squads by fire, protect the flanks and the rear of the platoon, and counterattack, if necessary.
    • It might be positioned on the counterslope to the rear of the forward squad if that position allows it to fire and hit the enemy when he reaches the crest of the defended hill.
  • Positioning the platoon command post to the rear where it will not interfere with the reserve or supporting units. Plans should consider that—
    • The platoon leader may have an observation post on the forward slope or crest and another on the reverse slope or counterslope.
    • The observation post is used on the forward slope or crest before the battle starts when the platoon leader is determining the enemy's intentions.
    • During the fight, he moves the observation post on the reverse slope or counterslope.
  • Planning indirect fire well forward of, on, and to the flanks of the forward slope, crest, reverse slope, and counterslope.
  • Planning direct final protective fires on the crest of the hill to control the crest and stop assaults.
  • Reinforcing existing obstacles.
  • Knowing that protective obstacles on the reverse slope―just down from the crest where it can be covered by fire―can slow the enemy's advance and hold him under friendly fire.
  • Knowing that the platoon leader normally plans for counterattacks and plans to drive the enemy off the crest by fire, if possible.
  • Knowing that the platoon leader also is prepared to drive the enemy off by fire and movement.

EMPLOYMENT

3-157. The Infantry leader can adopt a reverse slope position when ─

  • Enemy fire makes the forward slope untenable.
  • Lack of cover and concealment on the forward slope makes it untenable.
  • The forward slope has been lost or not yet been gained.
  • The forward slope is exposed to enemy direct fire weapons fired from beyond the effective range of the defender's weapons.
    • Moving to the reverse slope removes the attacker's standoff advantage.
  • The terrain on the reverse slope provides better fields of fire than the forward slope.
  • Surprising and deceiving the enemy as to the true location of the Infantry platoon’s defensive positions is essential.
  • Enemy weapons systems have overmatch in range and lethality.

3-158. When executing a reverse slope defense, the leader places special emphasis on ─

  • A direct and indirect fire support plan to prevent the enemy’s occupation and using crest of the hill.
  • The use of observation posts or reconnaissance elements on the forward slope to provide observation across the entire front and security to the main battle positions.
  • A counterattack plan specifying measures necessary to clear the crest or regain it from the enemy.
  • Direct and indirect fire support to destroy disrupt, and attrition of enemy forces on the forward slope.

3-159. The forward edge of positions should be within small arms range of the crest. It should be far enough from the crest, which fields of fire, allow the defender time to place well-aimed fire on the enemy before he reaches friendly positions. The platoon establishes observation posts on or forward of the topographical crest. This allows long-range observation over the entire front and indirect fire coverage of forward obstacles. Observation posts usually are provided by the unit owning the terrain being observed, and may vary in size from a few Soldiers to a reinforced squad. They should include forward observers. At night, their number should be increased to improve security.

SPECIAL CONSIDERATIONS

3-160. These are some considerations leaders may apply when defending on a reverse slope ─

  • Observation of the enemy is more difficult.
  • Soldiers in this position see forward no farther than the crest. This makes it hard to determine exactly where the enemy is as he advances, especially when visibility is poor.
  • Observation posts must be placed forward of the topographic crest for early warning and long-range observation.
  • Egress from the position might be more difficult.
  • Fields of fire are usually short.
  • Obstacles on the forward slope can be covered only with indirect fire or by units on the flanks of the company unless some weapons systems are placed forward initially.
  • If the enemy gains the crest, he can assault downhill. This may give him a psychological advantage.
  • If observation posts are insufficient or improperly placed, the defenders might have to fight an enemy who suddenly appears in strength at close range.
  • A reverse slope engagement is decisive resulting in one or both forces being severely attritted. Very difficult to break contact.
  • Placing the vehicles at the bottom of the hill and the infantry on counter slope allows the platoon to maximize its firepower into the engagement area as the enemy crests the slope.
  • The defender often has the opportunity to take the first shot at the attacker.