text: Chapter 13
  from one observation post to another, which allows the maintaining of the enemy contact without requiring
  security forces to displace. Security force commanders task subordinate units to perform reconnaissance and
  combat patrols to cover gaps between observation posts. Units place restrictive FSCMs around observation
  post locations to prevent fratricide.
  13-6. Observation posts may be either mounted or dismounted. Mounted observation posts can use their
  vehicular optics, weapons systems, and tactical mobility to displace rapidly when necessary. However, an
  enemy force can detect them more readily than dismounted observation posts. Dismounted observation posts
  provide maximum stealth but lack the speed of displacement, optics, and weapons of mounted ones. It takes
  a minimum of two Soldiers to establish an observation post, and then they can only operate effectively for
  no more than 12 hours. Observation posts manned for more than 12 hours require a minimum of an infantry
  squad or scout section to ensure continuous operation. The screening force patrols dead maneuver space and
  the area between observation posts, conducts resupply operations, and rests or sustains its personnel. In
  addition, under limited-visibility conditions, units can establish observation posts as listening posts to take
  advantage of the increased auditory acuteness that occurs when Soldier vision is degraded.
  COMBAT OUTPOSTS
  13-7. A combat outpost is a reinforced observation post capable of conducting limited combat
  operations. Using combat outposts is a technique for employing security forces in restrictive terrain that
  precludes mounted security forces from covering the area. Units also use combat outposts when enemy forces
  infiltrating into and through the security area could overrun smaller observation posts. They use a combat
  outpost to extend the depth of the security area, to keep friendly forward observation posts in place until they
  can observe the enemy force’s main body, or to secure friendly forward observation posts that enemy forces
  might encircle. Both mounted and dismounted forces can employ combat outposts.
  13-8. While the mission variables determine the size, location, and number of combat outposts a unit
  establishes, a reinforced platoon typically occupies each combat outpost. A combat outpost requires enough
  resources to accomplish its missions, but it should not seriously deplete the strength of the main body. It is
  usually located far enough forward of the protected force to preclude enemy ground reconnaissance elements
  from observing the actions of the protected force.
  13-9. Units organize the combat outpost to provide an all-around defense to withstand a superior enemy
  force. When the enemy force has significant armored capability, commanders may give combat outposts
  more antitank weapons. Forces operating combat outposts can conduct aggressive patrolling, engage and
  destroy enemy reconnaissance elements, and engage the enemy main body before their extraction. Units plan
  to extract friendly forces from their outposts before enemy forces overrun them.
  SECURITY OPERATIONS CONSIDERATIONS
  13-10. Commanders designate a security force when using any of the types of security operations. The
  protected force may not always be a military force; it can also be a civilian population, civil institutions, and
  civilian infrastructure in the unit’s assigned area. FM 3-90 describes security operations that focus on
  securing a force. Units may perform security operations to the front, flanks, or rear of their main body. All
  maneuver forces are capable of conducting security operations. To obtain proficiency in security operations,
  units need habitual support relationships with attachments and established SOPs. Commanders ensure that
  subordinate units perform the associated security tasks in support of their security operation.
  13-11. In addition to the operational and mission variables, there are several general considerations when
  performing security operations. These apply to all security operations, but they are most applicable to the
  performance of screen, guard, and cover operations. These additional considerations include—
  * Security fundamentals.
  * Commander’s security guidance.
  * Security forces size.
  * Location and orientation of the security forces.
  * Time the security force must be established.
  * Criteria for ending the security mission.