ADP 3-90, page 73

The Defense 31 July 2019 ADP 3-90 4-13 4-74. During planning, commanders use intelligence products to identify probable enemy objectives and approaches. From those probable objectives and approaches they develop named areas of interest and targeted areas of interest. In a defense, IPB should be able to determine an enemy force’s strength, COAs, and the location of enemy follow-on forces. IPB products also identify cyberspace activities, cross-domain capabilities, patterns of enemy operations and the enemy force’s vulnerabilities to counterattack, interdiction, electronic warfare, air attacks, and canalization by obstacles. Commanders study an enemy force’s capability to conduct air attacks against friendly forces, insert forces behind friendly units, employ CBRN and explosive weapons or devices, and employ asymmetric or unconventional forces and tactics. The intelligence staff also evaluates how soon enemy follow-on forces can be committed. Defending commanders can then decide where to arrange their forces to defend and shape the battlefield. 4-75. Commanders designate targeted areas of interest and named areas of interest as necessary. Commanders determine the most advantageous area for an enemy force’s main attack as well as other military aspects of terrain, including observation and fields of fire, avenues of approach, key terrain, obstacles, and cover and concealment. (See ATP 3-34.80 for a detailed discussion of observation and fields of fire, avenues of approach, key terrain, obstacles, and cover and concealment.) A defending unit continuously performs information collection tasks during a battle so that the defending commander can make the appropriate decisions and adjustments to the defense. 4-76. Some information collection assets are susceptible to loss. Defensive plans must also address the sustainment, replacement, and reconstitution of information collection assets throughout the execution of a defense. FIRES 4-77. The targeting process ensures the collective and coordinated use of Army indirect and joint fires to gain and maintain fire superiority throughout defensive operations. In the defense, commanders use fires to neutralize, suppress, or destroy enemy forces. Commanders can also use fires to delay or disrupt an enemy force’s ability to execute a given COA and to enhance the effects of massed direct fires or the employment of scatterable munitions. Army Indirect Fires and Joint Fires in the Defense 4-78. A defending force is less effective when an attacking enemy force can deploy in combat formations within the MBA. A defending force is more effective if it can locate and attack enemy forces while enemy forces are stationary and concentrated in assembly areas or advancing along LOCs. To engage enemy forces in vulnerable locations, a defending force must effectively employ available indirect and joint fires throughout its AO. A defending force must be closely linked to target acquisition means, including information collection assets. 4-79. As defensive plans develop, commanders visualize how to synchronize, coordinate, and distribute the effects of indirect and direct fires at decisive times and places. All elements in the fire support chain—from joint fires observers and platoon forward observers in fire support teams to the echelon fires cell, including the supporting tactical air control party and the supporting fires units—must understand the commander’s intent, the scheme of maneuver, and the obstacle plan. A defender’s ability to mass fires quickly and then rapidly reposition forces is a major factor in disrupting the enemy. Commanders place permissive FSCMs as close as possible to friendly positions to enable the rapid engagement of attacking enemy forces by indirect and joint fires. Commanders coordinate the massing of fire effects on enemy targets concentrated at obstacles and other choke points before they can disperse. Proper distribution of fires prevents the massing of enemy combat power at these points and ensures that friendly forces destroy or neutralize high-payoff targets without wasting assets through repetitive engagements by multiple friendly systems. 4-80. Fire support assets continue to target enemy combat units to force them to deploy once an engagement moves into the MBA. At the same time, fire support assets inflict casualties, disrupt the cohesion of an enemy force’s attack, and impede an enemy force’s ability to mass combat power. Commanders take advantage of the range and flexibility of fire support weapons to mass fires at critical points, such as obstacles and engagement areas, to slow and canalize an enemy force to provide better targets for direct fire systems. Fire support systems cover barriers, gaps, and open areas within the MBA.