text: Chapter 7
  7-154. Revising and refining the plan is a key activity of preparation. The commander’s situational
  understanding may change over the course of operations,enemy actions may require revision of the plan,or
  unforeseen opportunities may arise. During preparation,assumptions made during planning may be proven
  true or false. Intelligence analysis may confirm or deny enemy actions or show changed conditions in the
  area of operations because of shaping operations.
  Establish Security
  7-155. The first priority in the defense is to establish security. During the defense,effective security requires
  the establishment of the security area (forward of the MBA), the employment of patrols and observation
  posts,the use of manned and UASsand sensors,and the use of the terrain (cover and concealment). Security
  operations, counterreconnaissance, survivability operations, military deception, information-related
  capabilities, and CEMAs (specifically EW) counter enemy intelligence, surveillance, and reconnaissance
  from determining friendly locations,strengths,and weaknesses.
  7-156. Potential threats to the defense may include noncombatant access to communications, digital
  cameras, and similar devices. Security measures, such as shutting down telephone exchanges and cell
  telephone towers and preventing unauthorized personnel from moving in the BCT’s area of operations may
  be required. The BCT should request guidance from higher headquarters before implementing any security
  measures that could affect the civilian population.
  7-157. As part of the defense, higher headquarters may have created a military deception operation and
  associated information operations to protect the force, cause early committal of the enemy, or mislead the
  enemy as to the defender’strue intentions,composition,and disposition of friendly forces. The BCT aids in
  the preparation and execution of the military deception plan to—
  (cid:122) Exploit enemy prebattle force allocation and sustainment decisions.
  (cid:122) Exploit the potential for favorable outcomes of protracted minor engagements and battles.
  (cid:122) Lure the enemy into friendly territory exposing the enemy’s flanks and rear to attacks.
  (cid:122) Mask the level of the sustaining and operational forces committed to the defense.
  7-158. A defense containing branches and sequels gives the commander preplanned opportunities to exploit
  the situation and around these branches and sequels that deception potentials exist. Specific deceptive actions
  the BCT commander can take to hasten exhaustion of the enemy offensive include but are not limited to—
  (cid:122) Masking the conditions under which the enemy will accept decisive engagement.
  (cid:122) Luring the enemy into a decisive engagement that facilitates the transition sequence.
  (cid:122) Employing camouflage,decoys,false radio traffic,movement of forces,and the digging of false
  positions and obstacles.
  Occupation of Positions
  7-159. The BCT commander and staff monitor and deconflict any positioning problems with BCT or higher
  headquarters’ reconnaissance and security efforts as units move into their assigned areas of operation and
  occupy positions. The BCT may have to make minor adjustments to areas of operation,EAs,battle positions,
  and other defensive control measures based on unanticipated conditions the occupying units encountered as
  they begin preparing the defense.
  7-160. TheABEmonitors units assigned to close gaps or to execute directed obstacles such as demolition
  of bridges or dams to assure the units are ready to execute their mission. The ABEalso ensures the units site
  and complete all obstacle emplacements within the BCT according to the obstacle plan.
  Rehearsals
  7-161. The BCT conducts defensive rehearsals as time permits. The commander uses any,or combinations
  of, the four types of rehearsals: backbrief, combined arms rehearsal, support rehearsal, and battle drill or
  standard operating procedures (SOPs) rehearsal. Each rehearsal type achieves a different result and has a
  specific place in the preparation timeline. The commander’s imagination and available resources are the only
  limits restricting methods of conducting rehearsals. The BCT commander ensures the integration of attached