text: FM 7-100.1________________________________________________________________________________
  from targeting forces in the disruption zone or the battle zone. This is a key
  part of the OPFOR’s aggressive and creative counterreconnaissance effort.
  Battle Zone
  9-157. In maneuver or area defense, air defense units provide protection for
  the battle positions of DTGs or BTGs of the main defense force. In a maneuver
  defense, they especially cover units maneuvering from line to line. Especially in
  an area defense, they help preserve key components of OPFOR combat power or
  assist units in the stubborn holding of tactically favorable defensive positions
  that the OPFOR would prefer to retain. A typical battle position incorporates
  air defense systems, in conjunction with extensive use of C3D. In any type of
  defense, air defense units conduct air defense ambushes to provide opportunities
  for other forces to conduct counterattacks or reconnaissance fires.
  9-158. An OSC in the defense usually employs a strong reserve positioned in
  an assembly area with good C3D measures and strong air defense protection.
  The reserve must have sufficient air defense coverage to allow it to maneuver
  from the assembly area in order to conduct a variety of contingency missions
  the OSC commander might give it as the operation develops.
  Support Zone
  9-159. The OPFOR usually deploys some air defense units in the support zone
  to protect key logistics units and administrative support elements. However, it
  also relies heavily on passive air defense measures, including C3D and dispersal.
  ANTILANDING DEFENSE
  9-160. Air defense units have a significant role in defending ground forces
  against attacks by enemy airborne and air assault troops. When the OPFOR
  detects an enemy airborne operation, Air Force units (if available) attempt to
  intercept and destroy enemy transport aircraft. They try to do this while the
  enemy is at marshalling airfields or en route to drop zones.
  9-161. Operational- and tactical-level SAM units engage transport aircraft
  entering their respective air defense zones of responsibility. Short-range air
  defense assets near the drop zones also engage transport aircraft. These air
  defense forces typically act in the form of either air defense ambushes or roving
  air defense units. Self-propelled AA guns, vehicle-mounted machineguns, and
  small arms all fire on descending paratroops and equipment.
  SANCTUARY AREAS
  9-162. A sanctuary area may exist because of natural or manmade features.
  However, it only remains a sanctuary if the OPFOR can prevent the enemy
  from striking it with standoff weapons, including air power. Thus, OPFOR
  units in a sanctuary area use all available C3D techniques to reduce likeli-
  hood of detection or identification. They may also exploit political restrictions
  placed on the enemy force.
  9-163. The air defense of the sanctuary area is integrated into the overall air
  defense scheme at the tactical, operational, and strategic (national) levels. The
  net result is the requirement for enemy aviation to pass through overlapping