text: Chapter 7
  Figure 7-5. Historical example of a perimeter defense, Chip’yong Ni, 1951
  REVERSE-SLOPE DEFENSE
  7-93. The reverse-slope defense allows units to concentrate their direct fires into a relatively small area while
  being protected from the enemy’s direct observation and supporting fires. The defender can destroy the
  enemy’s isolated forward units through surprise and concentrated fires. The control of the forward slope is
  essential for success. Gaining control of the forward slope can be done by using dominating terrain behind
  the defenders or with the use of stay behind forces,such as reconnaissance and sniper teams,that can observe
  and call in fires on the attackers. Generally, a unit at battalion level and below conducts a reverse-slope
  defense even though the BCT may have areas within its area of operations that are conducive to the useof a
  reverse-slope defense.
  Reverse-Slope Defense:Kakazu Ridge 1945
  During the Okinawa campaign, Imperial Japanese forces conducted reverse-slope
  defenses along a series of ridges (seefigure 7-6). This tactic was devastating and cost many
  American lives. The Japanese,dug in on the reverse slope,and able to maneuver through
  tunnels would immediately counterattack American forces that reached the crest of the
  defended ridge. The Japanese held their positions for many days against heavy American
  firepower and repeated American attacks. Some of the positions, such as Kakazu Ridge,
  were taken,lost,and retaken repeatedly until finally falling to American forces.
  Various