text: Base Camp and Base Cluster Security and Defense
  E-26. Although not a fundamental of security operations, the use of dispersion is an important technique that
  commanders should consider. Dispersing units, command posts, equipment, and personnel reduces
  vulnerability against enemy direct- and indirect-fire threats and CBRN attacks. However, units should be
  close enough to provide mutual support against enemy ground attacks. Commanders must determine where
  risk is acceptable.
  E-27. Base camps and base clusters typically protect their personnel and assets through the application of
  security activities. Some essential security activities include communications security, cybersecurity,
  information security, OPSEC, personnel security, and physical security. Of the five security tasks listed in
  ADP 3-90—screen, guard, cover, area security, and local security—only area security and local security
  typically apply to base camps and base clusters. Area security preserves the base camp and base cluster
  commander’s freedom to move reserves, position fire support means, provide for mission control, conduct
  sustaining activities, and coordinate for reinforcing forces (see chapter 2). Local security provides immediate
  protection to base camp forces and assets. See ADP 3-37 and ADP 3-90 for additional information on area
  and local security.
  BASE CAMP DEFENSE
  E-28. Defensive operations are operations to defeat an enemy attack, gain time, economize forces, and
  develop conditions favorable for offensive or stability operations (ADP 3-0). Base defense refers to the local
  military measures, both normal and emergency, required to nullify or reduce the effectiveness of enemy
  attacks on, or sabotage of, a base to ensure the maximum capacity of its facilities is available to United States
  forces (JP 3-10). Successful base camp and base cluster defenses share the following characteristics:
  disruption; flexibility; maneuver; massing effects; and operations in depth, preparation, and security. The
  basic defensive tasks are applicable to the area and perimeter of the base camp. See ADP 3-90 for a discussion
  of these characteristics.
  Area Defense
  E-29. Conducting area defense is a defensive task that concentrates on denying enemy forces access to a base
  camp, base cluster, or surrounding terrain. The focus of the area defense is on retaining terrain where the bulk
  of the defending force positions itself in mutually supporting, prepared positions. Units maintain their
  positions and control the terrain between these positions. An area defense capitalizes on the strength inherent
  in a closely integrated base camp defense. The higher commander may assign subordinate units or tenant
  organizations the task of conducting an area defense as part of their mission. Subordinate echelons defend
  within their assigned AOs as part of the larger-echelon operation. See FM 3-90-1 for more information on
  area defense.
  Perimeter Defense
  E-30. The commander can employ perimeter defense as an option when conducting an area defense or in the
  conduct of base camp and base cluster defense in the echelon support. A perimeter defense is oriented in all
  directions. The prerequisites for a successful perimeter defense are aggressive patrolling and security
  operations outside the perimeter. The unit within the perimeter can perform these activities; or another force,
  such as the territorial defense forces of a host nation, can perform them. The unit can organize a perimeter
  defense to accomplish a specific mission, such as protecting a fire base. A unit may also form a perimeter
  when it is located in the friendly echelon support area within the confines of a base camp or base cluster.
  E-31. A major characteristic of a perimeter defense is a secure inner area, with most of the combat power
  located on the perimeter. Another characteristic is the ease of access for resupply operations. The commander
  coordinates direct- and indirect-fire plans to prevent accidentally engaging neighboring friendly units and
  noncombatants. Normally, the reserve centrally locates to react to a penetration of the perimeter at any point.
  See FM 3-90-1 for more information on perimeter defense.