text: Chapter 13
  13-126. Units executing area security focus on the protected force, installation, route, or area. Protected
  forces range from echelon headquarters, artillery, and echelon reserves to the sustaining base. Protected
  installations can also be part of the sustaining base, or they can constitute part of the area’s infrastructure.
  Areas to secure range from specific points (bridges and defiles) to terrain features (ridgelines and hills), to
  large civilian population centers and their adjacent areas. Population-centric area security missions are
  conducted at any time but are almost a fixture during irregular warfare. These population-centric area security
  missions typically combine aspects of the area defensive and offensive operations to eliminate the effect of
  internal defense threats.
  13-127. Typically, units assigned an area security mission operate in a division or higher echelon’s rear area
  and facilitate the positioning, employment, and protection of resources required to sustain, enable, and control
  forces. Area security in the rear area preserves the commander’s freedom to move reserves, position fire
  support capabilities, provide command and control, and conduct sustaining operations.
  13-128. Forces engaged in area security are typically organized in a manner that emphasizes their mobility,
  lethality, and communications capabilities. The task organization of the unit assigned the area security
  mission should correspond with the level of threat. For example, if the threat is a Level II threat, a military
  police company should be sufficient. If the threat is a Level III threat, a combined arms team from a brigade
  combat team is a more appropriate unit. Friendly forces conducting area security initially provide early
  warning against an unexpected enemy or adversary attack and then, within capabilities, defeat those attacks.
  Early warning may come from ground, aerial, or space-based sensors. Area security may provide
  reconnaissance on NAIs to answer commander’s critical information requirements, aiding in tactical decision
  making and confirming or denying threat intentions.
  13-129. All commanders apportion combat power and dedicate assets based on an analysis of the operational
  environment, the likelihood of threat action, the relative value of friendly resources, and risk to civilian
  populations. Although all friendly resources have value, the mission variables of METT-TC (I) make some
  resources, assets, or key terrain more essential to successful mission accomplishment from enemy or
  adversary and friendly perspectives. Commanders create and use a decision support matrix and template to
  facilitate decision making, issue guidance, and allocate resources. Criticality, vulnerability, and
  recoverability are some of the most significant considerations in determining protection priorities that
  become the focus of area security.
  13-130. A unit restrains its use of force when conducting area security operations when civilians are present.
  However, commanders remain responsible for protecting the force, and they consider this responsibility when
  establishing rules of engagement. They explain restrictions on conducting operations to ensure everyone
  understands those restrictions. Soldiers must understand that their actions may have far-reaching positive or
  negative effects. Commanders communicate that media and adversaries can quickly exploit Soldiers’ actions,
  especially the way they treat civilians.
  13-131. Sometimes area security forces must retain readiness over long periods without contact with enemy
  forces. This occurs most often when the enemy special purpose forces or insurgents are overmatched. In this
  case, the enemy normally tries to avoid engaging friendly forces unless it is on terms favorable to the enemy.
  Forces conducting area security should not develop a sense of complacency, even if the enemy force appears
  to have ceased operations in the secured area. Additionally, friendly forces should be mindful of mines and
  booby traps in these situations. Successful units assume that the enemy force regularly observes friendly
  operations to identify routines, weak points, and lax security for the opportunity to strike with minimum risk.
  This requires leaders to maintain vigilance and discipline in their Soldiers to prevent that opportunity from
  developing.
  13-132. Area security focuses on the following activities:
  * Site security. Area security forces provide protection through area security techniques that involve
  the employment of protection and security assets in a layered, integrated, redundant manner. A
  unit conducting site security may protect locations such as—
   Base/base camp defense. Base defense consists of 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 that the maximum capacity of its facilities is available to United
  States forces (JP 3-10).