text: Support to Large-Scale Ground Combat
  defender can postpone the commitment of major forces until the attack develops and then strike the extended
  enemy over selected, prepared terrain.
  Disruption, flexibility, maneuver, massing effects, operations in depth, preparation, and security
  characterize successful defensive operations, as depicted in FM 3-90-1. Defensive operations have a distinct
  preparation phase, which is vital to setting the conditions for combat and to giving the defender the tactical
  advantage against an attacker. The mission of the engineer staff officer and engineer commanders is to plan
  and execute engineer efforts that enhance the ability of the defending unit to combine fires, obstacles, and
  maneuver to destroy an attacking enemy. The success of engineers in the preparation of the defense depends
  largely on the ability of the division echelon engineer to conduct integrated planning with the division staff
  and parallel planning with supporting and subordinate engineer units. The division echelon engineer uses
  parallel planning to disseminate the information and intent needed to foster early planning and the preparation
  efforts required at subordinate levels. The division scheme of engineer operations, task organization, obstacle
  control, survivability guidance, and allocation of resources (barrier materials, munitions, and construction
  equipment) enable and focus subordinate unit engineer efforts. With the information provided, subordinate
  units can anticipate the limitations of allocated capabilities and prioritize efforts and resources to mitigate
  limitations.
  Engineer support to the defense includes the simultaneous application of combat, general, and
  geospatial engineering capabilities through synchronizing warfighting functions throughout the depth of the
  AO. Combat engineering in close support of maneuver forces is the primary focus in the defense; however,
  the three disciplines apply simultaneously to some degree. Figure 4-2 shows a notional application of
  engineering capabilities supporting the defense and the preponderance of the weight of activities performed.
  Legend:
  COP common operational picture
  EA engagement areas
  FACE forward aviation combat engineering
  SSGF standard and shareable geospatial foundation
  Figure 4-2. Notional engineer support to defensive operations