text: FM 7-100.1________________________________________________________________________________
  • Conducting counterpenatration (blocking or destroying enemy pene-
  trations).
  • Conducting antilanding operations (eliminating vertical envelopments).
  • Assisting forces heavily engaged on a defended line to break contact
  and withdraw.
  • Act as a deception force.
  4-63. Antitank Reserve. OPFOR commanders faced with significant ar-
  mored threats may keep an antitank reserve (ATR). It is generally an anti-
  tank unit and often operates in conjunction with an obstacle detachment (OD).
  Based on the availability of antitank and engineer assets, an operational-level
  command may form more than one ATR.
  4-64. Antilanding Reserve. Because of the potential threat from enemy
  airborne or airmobile troops, an operational-level commander may designate
  an antilanding reserve (ALR). Operational-level ALRs would be resourced for
  rapid movement to potential drop zones (DZs) and landing zones (LZs). The
  ALR commander would have immediate access to the operational intelligence
  system for early warning of potential enemy landing operations. ALRs typically
  include maneuver forces, air defense assets, and engineer units, but may be
  allocated any unit capable of disrupting or defeating an airborne or heliborne
  landing, such as smoke or electronic warfare (EW). While other reserves can
  perform this mission, the commander may create a dedicated ALR to prevent
  destabilization of the defense by vertical envelopment of OPFOR units or seizure
  of key terrain. ALRs assume positions prepared to engage the enemy primary DZ
  or LZ as a kill zone. They rehearse and plan for rapid redeployment to other sus-
  pected DZs or LZs. Operational-level commanders may direct long-range fires or
  SPF direct action to prevent enemy forces from mounting air insertions. The de-
  struction of airframes or fuel sources, or the positioning of air defense assets may
  serve to take this option away from enemy forces.
  4-65. Special Reserves. An operational-level command may form an
  engineer reserve of earthmoving and obstacle-creating equipment. A com-
  mander can deploy this reserve to strengthen defenses on a particularly
  threatened axis during the course of the operation. An operational-level
  command threatened by enemy use of WMD may also form a chemical
  defense reserve.
  Deception Force
  4-66. When the IW plan requires the creation of nonexistent or partially ex-
  isting formations, these forces are designated deception forces in close-hold
  executive summaries of the operation plan. Wide-distribution copies of the
  plan make reference to these forces according to the designation given them in
  the deception story. The deception force in the defense is typically given its own
  command structure to both replicate the organization(s) necessary to the decep-
  tion story and to execute the multidiscipline deception required to replicate an
  actual military organization. For example, FG commanders can use deception
  OSC command structures to deny enemy forces information on operation plans
  for the defense.