ADP 3-90, page 75

The Defense 31 July 2019 ADP 3-90 4-15 4-88. Commanders may need to infiltrate resupply vehicles to reduce detection chances when an enemy force possesses a significant air, satellite, or unmanned aircraft capability. Commanders may also use military deception, camouflage, concealment, and obscurants to help conceal logistic operations. 4-89. Terrain management is a critical consideration when establishing bases and base clusters in the support area. Commanders position each sustainment unit where it can best fulfill its support tasks while using minimal resources to maintain security in conjunction with other units located in an echelon support area. In contiguous operations, commanders position echelon sustainment facilities farther away from the FEBA in a defense than in the offense to avoid interfering with the movement of units between battle positions or the forward movement of counterattack forces. Commanders locate these assets far enough behind friendly lines that likely enemy advances will not compel the relocation of critical sustainment capabilities at inopportune times. However, those sustainment capabilities supporting a unit must be close enough to provide responsive support. In noncontiguous operations, commanders position sustainment assets in bases and base clusters within the perimeters of ground maneuver units to provide security and avoid interrupting their sustainment functions. Commanders distribute sustainment units with similar functions throughout the defensive area in both environments. This distribution allows commanders to designate one sustainment unit to pick up the workload of a displacing second sustainment unit until the second sustainment unit is once again operational. (See ATP 3-91 for a discussion of the use of bases and base clusters within the division support area.) 4-90. A defending commander provides maintenance support as far forward as possible at maintenance collection points to reduce the need to evacuate equipment. The goal of the maintenance effort is to fix as far forward as possible damaged systems that can be quickly returned to a unit in combat-ready condition. Commanders ensure that multifunctional forward logistic elements contain the maximum variety of maintenance personnel with appropriate equipment, such as repair sets, kits, and outfits, to rapidly repair weapon systems. 4-91. Medical support associated with the defense anticipates significant casualties, just as in the offense. Commanders plan to augment available ambulances for mass casualty situations. Units plan for mass casualties and have evacuation plans, including casualty collection points and ambulance exchange points, and account for the use of both standard and nonstandard air and ground evacuation platforms. PROTECTION 4-92. In defensive operations, commanders protect forces and critical assets by synchronizing, integrating, and organizing protection capabilities and resources. Commanders incorporate available protection capabilities as they understand and visualize threats and hazards in an operational environment. Commanders then apply the elements of combat power to prevent or mitigate these threats or hazards from negatively impacting friendly operations. Commanders use decision support tools and analysis to assess a unit’s critical assets and key vulnerabilities. (See ADP 3-37 for additional information on protection.) 4-93. In defensive operations, commanders protect forces and critical assets by performing security operations. Forces providing security in a defense can deter, detect, or defeat enemy reconnaissance efforts while creating standoff distances from enemy direct- and indirect-fire systems. Commanders secure the movement of combat trains and protect cached commodities. 4-94. Commanders clearly define responsibilities for the security of units within the support area. This requires assigning an individual responsibility for defensive planning and risk mitigation in that support area. That individual can designate the commanders of tenant units within support areas as base and base cluster commanders (except medical corps officers). Base and base cluster commanders are responsible for the local security of their respective bases and base clusters. A commander responsible for a support area can also designate protection standards and defensive readiness conditions for tenant units and units transiting the area. Higher protection standards may impact the ability of those supporting sustainment units to accomplish their primary missions to support the operations of maneuver and other forces. The support area commander coordinates to mitigate the effects of performing security operations on the primary functions of units located within an echelon support area. (There are two approaches for arraying base camps: dispersed and consolidated. See ATP 3-37.10 for the strengths and weaknesses of each approach.) 4-95. Troop movements and resupply convoys are critical. Staffs balance terrain management, movement planning, convoy security requirements, and traffic-circulation control priorities. They plan multiple routes