text: _________________________________________________________________________________Chapter 9
  provide general area coverage of the OSC’s entire AOR. This area coverage
  gives depth to the defensive effort and overlaps with envelopes of tactical
  units. Where possible, this SAM coverage overlaps the envelopes of adjacent
  operational-level commands.
  9-131. The medium-range SAM units engage enemy aircraft at some distance
  from tactical maneuver units and other high-value assets within the OSC’s
  AOR. These SAMs and shorter-range AA guns also protect key targets such
  as operational-level CPs, tactical ballistic missiles (TBMs), long-range
  rockets and artillery, and reserves.
  TACTICAL-LEVEL
  9-132. In the best-case situation, a division or DTG will have sufficient air
  defense assets to provide area coverage over its AOR, including the AORs of
  subordinate units. At brigade or BTG level, there is a significant element of
  point protection in support of subordinate units and brigade- or BTG-level
  assets. This is due to the nature of the units defended and the relatively
  short range of air defense weapons at this level.
  9-133. Tactical-level short- and medium-range SAMs provide area coverage for
  the entire tactical-level unit, overlapping with the envelopes of flanking units.
  Short-range AA guns and shoulder-fired SAMs can provide point protection.
  AIR DEFENSE UMBRELLA
  9-134. Air defense assets from national down through tactical level create an
  air defense umbrella. Radars can provide an unbroken detection envelope ex-
  tending well into enemy territory and across the entire AOR. If OPFOR
  fighter-interceptors are able to operate farther out against enemy aircraft in
  the “flight area,” national-level long- and medium-range SAMs might be the
  first to engage enemy aircraft that slip past fighters. When OPFOR fighters
  must operate in “friendly” OPFOR airspace, the national-level SAMs proba-
  bly would be the first air defense assets to engage the enemy aircraft. The
  next layer of defense is operational-level medium-range SAMs. The final layer in
  the battle zone would consist of tactical-level SAMs and AA guns. If enemy aircraft
  escape air defenses in the battle zone, they may still encounter operational- or
  national-level air defense systems protecting key assets in the support zone.
  This deployment scheme causes enemy aircraft to run into overlapping defensive
  systems as they approach and penetrate the airspace over OPFOR units.
  9-135. There is no set pattern for the deployment of air defense assets. A
  basic and flexible guideline is that, depending on their functions and weapon
  capabilities, air defense units occupy positions at a distance from the battle
  line that ensures the accomplishment of their mission and provides relative
  safety from enemy fire. For area coverage, this generally means that weap-
  ons at the operational level and below deploy rearward from the supported
  unit’s battle line at from one-third to one-half of their engagement range.
  However, the OPFOR recognizes that “rules of thumb” are just that, and the
  operational or tactical situation and common sense may dictate that these
  distances be modified. Actual deployment depends primarily on the supported
  unit’s mission, terrain, and the ground and air situations at a given time and
  place in the operation. Sometimes, air defense systems can be much closer to the