text: FM 7-100.1________________________________________________________________________________
  OFFENSIVE COUNTERMOBILITY
  10-57. Engineer countermobility missions are not strictly an engineer function.
  Rather, they are part of an overall, all-arms effort to deny the enemy freedom
  of maneuver. For example, many remotely-delivered mines are emplaced by
  means other than engineer assets. The OPFOR will also employ all means
  available to attack the enemy’s mobility assets at every opportunity. The
  elimination or degradation of key mobility assets (such as bridging and mine-
  clearing assets) can severely limit the enemy’s progress, range, or sustain-
  ability. This is part of the OPFOR’s systems warfare approach to combat.
  10-58. Preemptive attacks against the enemy’s bridging and mineclearing
  systems can occur at very early stages in the conflict, often well before the
  foreseen usage of such mobility assets. The OPFOR might try to destroy all
  mobility assets, thereby confining the enemy to his aerial or sea port of
  debarkation (APOD or SPOD), or it might let the enemy commit his assets
  and then destroy them piecemeal. Whichever method the OPFOR chooses, it
  would attempt to mask the identity of the true target by also hitting what the
  enemy may deem “higher-value targets,” such as maneuver troops and equip-
  ment, during the same attack. Thus, the enemy may believe the destruction of
  his mobility assets to be collateral damage rather than the intended target, and
  he may not place a high priority on replacing these as critical items.
  STRATEGIC CONTEXT
  10-59. Operational-level engineers support the State’s various strategic-level
  courses of action and the OPFOR principles of operations versus an
  extraregional power (discussed in Chapter 1 and in FM 7-100). Specific
  engineer requirements are determined by the operational mission of the sup-
  ported OSC within whichever strategic-level course of action is occurring in a given
  AOR at a given time. That may be regional, transition, or adaptive operations.
  Because of the requirement to transition rapidly from regional to adaptive
  operations and perhaps back to regional operations, engineers assigned to
  OSCs may be supporting more than one course of action simultaneously.
  REGIONAL OPERATIONS
  10-60. Operational-level engineer units involved in regional operations facilitate
  the mobility and high rate of advance of joint, combined arms, interagency,
  and/or multinational forces while enhancing the survivability of forces.
  Although the OPFOR generally conducts engineer countermobility activities
  at the tactical level, it tailors the obstacle plan to the overall operation and
  integrates it into the operation plan. It uses obstacles to disaggregate, delay,
  block, and canalize enemy forces.
  TRANSITION OPERATIONS
  10-61. Since transition operations can overlap both regional and adaptive
  operations, engineer actions can be various combinations of those occurring
  during regional or adaptive operations. The need for rapid transition from
  regional to adaptive operations (and vice versa) presents the engineers
  several challenges. For example, engineers still supporting regional
  operations may be involved in water-crossing activities, while engineers