text: Chapter 8
  Security Operations
  8-56. The main difference between conducting security operations and reconnaissance is that security
  operations orient on the force or facility being protected while reconnaissance orients on the enemy and
  terrain. Security operations aim to protect a force from surprise and reduce the unknowns in any situation.
  Commanders conduct security operations to the front, flanks, or rear of their forces, which may be moving
  or stationary. Their goal is to determine the enemy’s COA and assist the main body in defeating enemy
  forces. For security operations, economy of force is often considered during planning. The following are the
  four types of security operations:
  ⚫ Area security is a type of security operation conducted to protect friendly forces, lines of
  communications, installation routes and actions within a specific area (FM 3-90). The security
  force may be protecting the civilian population, civil institutions, and civilian infrastructure
  within a unit’s assigned area.
  ⚫ Cover is a type of security operation done independent of the main body to protect them by
  fighting to gain time while preventing enemy ground observation of and direct fire against the
  main body (ADP 3-90). A force tasked to cover may do so offensively or defensively.
  ⚫ Guard is a type of security operation done to protect the main body by fighting to gain time
  while preventing enemy ground observation of and direct fire against the main body
  (ADP 3-90). Units performing a guard cannot operate independently. They rely on fires and
  functional and multifunctional support assets of the main body. A force tasked to guard may do
  so offensively and defensively.
  ⚫ Screen is a type of security operation that primarily provides early warning to the protected force
  (ADP 3-90). Screens provide less protection than guards or covers. Screen missions are
  defensive in nature and accomplished by establishing a series of observation posts and patrols to
  ensure observation of the assigned area. The screen force gains and maintains enemy contact
  consistent with the OPORD and destroys or repels enemy reconnaissance units by conducting
  counterreconnaissance.
  8-57. Main body commanders designate the size of the security force and its mission. This designation
  determines the limit of the security forces’ responsibilities to perform screen, guard, cover, and area security
  operations. Table 8-2 shows the typical sizes of security forces at various echelons in relation to their
  missions. The limited capabilities of most maneuver platoons prohibit them from having a mission separate
  from their parent company; scout platoons are the exception to this rule.
  Table 8-2. Typical security force echelon for a given mission and echelon
  Security mission
  Echelon Guard
  Screen Cover
  Advance Flank or rear
  Echelons above corps
  (joint force land CAB, armored BCT, Reinforced corps or CAB, armored BCT, or Reinforced corps or
  components or numbered Stryker BCT division Stryker BCT division
  Army)
  Division, armored BCT,
  CAB, combined arms
  Division, armored BCT, Stryker BCT, combined Reinforced division or
  Corps battalion, battalion task
  Stryker BCT arms battalion, battalion armored BCT
  force
  task force
  Reinforced cavalry
  Cavalry squadron,
  Reinforced cavalry squadron, combined
  Division combined arms battalion, Reinforced BCT
  squadron or BCT arms battalion, or
  or battalion task force
  battalion task force
  Reinforced combined
  BCT Company team Battalion task force arms battalion, or
  battalion task force
  Battalion task force Scout platoon
  BCT brigade combat team CAB combat aviation brigade