text: Chapter 6
  attack the enemy, even as his forces are preparing for and executing the defense. As discussed in Chapter 1,
  a characteristic of the FA is to always operate in the spirit of the offense, even when maneuver forces are in
  the defense.
  THE ENEMY ATTACK
  6-30. During offensive operations, enemy forces typically attempt to mask the location of their main effort
  with multiple fixing attacks on the ground while using fires to disrupt critical friendly CPs, radars, and FDCs.
  Generally, enemy forces seek to reinforce success, massing capabilities at a vulnerable point to achieve large
  force ratio advantages to enable a rapid penetration of friendly defenses. The enemy uses mobile forces to
  exploit the penetration rapidly to the maximum possible depth in order to make the overall friendly defensive
  posture untenable.
  6-31. Threat forces can have advantages in both volume and range of fires, so they can simultaneously mass
  fires on the point of penetration to enable rapid closure and breakthrough, fix other friendly elements along
  the FLOT, and target key friendly C2 and logistics nodes along the depth of the defense. Threat forces prefer
  to use fires to move around fixed positions when possible and through destroyed units when necessary. Threat
  forces seek to maneuver tactically to a depth that achieves operational objectives in support of his overall
  strategic purpose.
  6-32. Threat forces may employ ISR, EW, information warfare, SOF, CBRN and other capabilities. For more
  information on enemy attack see FM 3-0.
  COMMON DEFENSIVE CONTROL MEASURES
  6-33. Commanders control a defense by using control measures that provide flexibility needed to allow
  defending commanders to concentrate combat power and the decisive point. Below are defensive control
  measures that every FS leader should understand in order to best support the commander. For more
  information on defensive control measures see ADP 3-90.
  6-34. The security area is that area occupied by a unit's security elements and includes the areas of influence
  of those security elements (ADP 3-90). It may be located as necessary to the front, flanks, or rear of a
  protected unit, facility, or location. FS in the security area engages enemy reconnaissance elements early in
  order to delay, disrupt, or limit the enemy's advance. FS is planned to assist the supported commander in
  moving and disengaging as well as integrating FS and obstacle plans to ensure obstacles are covered by direct
  observation. FS considerations for defensive operations in the security area will be discussed in subsequent
  under reconnaissance and security operations. See figure 6-2.
  6-35. The main battle area is the area where the commander intends to deploy the bulk of their unit to defeat
  an attacking enemy (FM 3-90). Normally, most of the defending force is deployed in the main battle area
  (MBA) to defeat the enemy's main attack. The mission of the MBA forces at corps level covers the entire
  spectrum of operations. Thus, while the corps as a whole may be engaged in defensive operations, units
  within the corps AO (divisions, BCTs, TFs) may be conducting any type of defensive or offensive operation
  in the MBA. FS for the MBA is allocated with the priority to the most vulnerable area which usually coincides
  with the enemy's most likely avenues of approach and main attack. These areas must be weighed more heavily
  with immediately responsive fires such as CAS and DS or (R) FA. Detailed FS considerations for defensive
  operations and offensive operations in the MBA are discussed later in this chapter. See figure 6-2.
  6-36. The forward edge of the battle area is the foremost limits of a series of areas in which ground combat
  units are deployed to coordinate fire support, the positioning of forces, or the maneuver of units, excluding
  areas in which covering or screening forces are operating (JP 3-09.3) See figure 6-2. FS short of the forward
  edge of the battle area consists of close support tasks such as supporting friendly units in contact, supporting
  strongpoints, supporting obstacles, suppressing, and obscuring enemy overwatch positions, supporting
  counterattacks, and coordinating CAS and attack aviation to engage enemy armored formations. See figure
  6-2.
  6-37. The forward line of own troops is a line that indicates the most forward positions of friendly forces in
  any kind of military operation at a specific time (FM 3-90). In the defense, it may be beyond, at, or short of
  the forward edge of the battle area. FS beyond the FLOT acquires and engages enemy reconnaissance