text: Chapter 13
  Security Operations
  This chapter addresses those considerations unique to the performance of security
  operations. General offensive and defensive considerations discussed previously in this
  manual continue to apply to security operations. This chapter addresses the general
  security considerations and types of security operations.
  GENERAL SECURITY OPERATIONS CONSIDERATIONS
  13-1. Security operations are those operations performed by commanders to provide early and accurate
  warning of enemy operations, to provide the forces being protected with time and maneuver space within
  which to react to the enemy, and to develop the situation to allow commanders to effectively use their
  protected forces (ADP 3-90). They prevent surprise, reduce uncertainty, and provide early warning of enemy
  activities. Security operations are a dynamic effort that anticipates and thwarts enemy collection efforts.
  When successful, security operations allow the force to maintain the initiative.
  13-2. Security operations are not to be confused with the more general term of security. Security is measures
  taken by a military unit, activity, or installation to protect itself against all acts designed to, or which may,
  impair its effectiveness (JP 3-10). Security includes a wide range of activities such as preventing unauthorized
  access into secure areas or establishing perimeter security around an operating base. Security is inherent in
  all operations and is always the first priority of work. Furthermore, security is the responsibility of every
  Soldier and unit whereas security operations are distinct missions.
  13-3. The main difference between the performance of security operations and reconnaissance operations is
  that security operations orient on the force, area, or facility, while reconnaissance operations orient on enemy
  and terrain. Security operations are supporting efforts. As a supporting effort, economy of force is often a
  condition associated with the performance of security operations. Security operations are essential for
  preserving friendly forces combat power. Paragraphs 13-4 through 13-9 include general security
  considerations that are applicable to all security operations and units.
  LOCAL SECURITY
  13-4. Local security is the low-level security activities conducted near a unit to prevent surprise by the
  enemy. All units are responsible for their own local security and responding to Level I threats. Local security
  is not an operation of its own. It includes any local measure taken by units that protect against enemy actions.
  It involves avoiding enemy detection or deceiving the enemy about friendly positions and intention. Local
  security provides immediate protection to friendly forces and is typically performed by a unit for self-
  protection, but it may also be provided by another unit when the security requirements are greater than the
  unit security capabilities. Local security may include countermobility and survivability activities as well as
  the use of active and passive measures to provide local security.
  OBSERVATION POSTS
  13-5. An observation post is a position from which observations are made or fires are directed and
  adjusted. All observation posts should possess appropriate communications. While aerial observers and
  sensor systems are extremely useful, those systems do not constitute aerial observation posts. The security
  force unit determines tentative initial observation post locations along or behind the screen line to ensure
  effective surveillance of their sectors of observation and designated NAIs. The unit or asset that occupies
  each observation post may shift its exact location to achieve the commander’s intent. Units may place more
  than one observation post along high-speed avenues of approach to allow the tracking of an enemy contact