Over the past several decades, the focus of Army operations and training, as well as the accompanying command relationships, was on counterinsurgency and the global world threat. However, the threat has evolved, and doctrine in Field Manual (FM) 3-0, Operations, within the context of unified land operations, recognizes that our focus must shift to readiness for large-scale ground combat against a peer threat. This reality has significant implications for sustainment command relationships.DOCTRINE AND FORCE STRUCTUREDoctrine and force structure have been based on brigade combat team (BCT)-centric, forward operating base-oriented counterinsurgency operations. The Army created and refined a centralized sustainment mission command doctrine built on a sustainment hierarchy with sustainment brigades, expeditionary sustainment commands (ESCs), and theater sustainment commands (TSCs) to effectively provide support to BCT-centric operations, particularly in counterinsurgency operations.The resultant structure of echelons-above-brigade sustainment organizations and centralized mission command removed the fixed capability that the Army previously had in the division support commands and corps support commands. It also moved some support capabilities, such as distribution, water purification, and fuel storage, from the BCT to echelons-above-brigade units to enable commanders at that level to weight support to the force.Although doctrine always has recognized commanders' flexibility to establish command relationships, it prescribed that the TSC would normally be assigned to the theater army, the ESC would be attached to a TSC, and the sustainment brigade would be attached to the ESC. A command relationship in which sustainment units belonged to maneuver units was viewed as the exception.LARGE-SCALE COMBAT OPERATIONSThese sustainment command relationships worked in the operations we were conducting during counterinsurgency operations. However, the operational environment described in FM 3-0, with a re-emerging threat from peer competitors, contested domains, and renewed focus on winning the next fight through large-scale combat operations, poses challenges for that command approach.We will face a chaotic operational environment in the next conflict that includes increased lethality, contested lines of communication, long-range precision fires, mass casualties, dispersed forces, cyber warfare, communications jamming, and other challenges not seen since World War II.In response, corps and divisions will operate as formations, not just as headquarters. The next large-scale ground combat operation will see multiple divisions and potentially multiple corps maneuvering forces on the battlefield. These new roles and responsibilities demand new command relationships for supporting sustainment organizations.Corps and division commanders operating as formation commanders will require command and control over sustainment organizations in order to fully integrate sustainment into planning and operations and to rapidly respond to adaptive threats in very complex environments.NEW COMMAND RELATIONSHIPSFM 3-0 spells out a new set of doctrinal relationships to deal with those situations. It specifies that if a TSC is not deployed or if leaders want to achieve special effects, an ESC may have a command relationship with a corps headquarters. It also says that although "sustainment brigades normally remain attached to the TSC or ESC," they may also have a command relationship with the maneuver headquarters, for example, during high-tempo large-scale combat operations.As we complete the new FM 4-0, Sustainment Operations, we will extend the concept of the command relationships required to effectively support large-scale combat operations. At the corps level, we believe that the ESC should be attached to the corps headquarters in operations and provide general support to forces operating in the corps area and to the divisional sustainment brigades.The ESC will be task-organized with one or more sustainment brigades, each of which will have an assigned special troops battalion (STB). That STB will have an organic signal company, human resources company, and financial management support unit. The sustainment brigade will also have one or more task-organized combat sustainment support battalion (CSSB) attached. A sustainment brigade attached to a corps ESC may also have a petroleum battalion and a motor transportation battalion to support tactical-level sustainment operations.The CSSBs attached to sustainment brigades supporting the corps will normally include a composite supply company, support maintenance company, modular ammunition company, field feeding company, palletized load system truck company, and an inland cargo transfer company.At the division echelon, we are recommending a refinement to doctrine by having the theater army assign a sustainment brigade to a division headquarters. We are also looking at designating such a brigade as a division sustainment brigade (DSB). As directed by the division commander, that brigade would have command and control over all assigned and attached units that provide direct support logistics, personnel services, and financial management to forces operating in the division area of operation.This brigade would enable fully integrated sustainment support to a division operating as a formation. The DSB could also be assigned general sustainment support to field Army and corps units operating in the division support and consolidation areas. Like its counterpart at the corps echelon, the DSB would be assigned an STB with an organic signal company, human resources company, and financial management support unit. It would also be assigned one divisional CSSB (that could be renamed as a maneuver support battalion).At a minimum, that CSSB would include an organic composite supply company, composite truck company, support maintenance company, and field feeding company. As required by the situation, the CSSB could also be task-organized with additional light/medium or heavy transportation companies, cargo transfer companies, petroleum transportation companies, modular ammunition companies, movement control teams, and water support companies.WITHIN THE MEDICAL COMMUNITYWe are also exploring new relationships between medical units in the theater and other sustainment organizations. Currently the Army has a centralized medical mission command hierarchy with medical units commanded by a medical command (deployment support). This command structure may not be effective for fully and quickly integrating medical support with other sustainment during large-scale ground combat.We are investigating a set of command relationships between medical and sustainment organizations to better synchronize support. This includes attached relationships between a medical command (deployment support) and a TSC; between a medical brigade, combat support hospital, and hospital center and an ESC; and between a multifunctional medical battalion and a sustainment brigade. We are also looking at assigning a medical company with medical logistics to a CSSB.Command relationships for medical detachments would remain at the discretion of the medical command (deployment support), which would also continue to command medical units that do not have designated command relationships with sustainment headquarters. These command relationships are still being assessed and would require the addition of medical operations, medical planning, and medical logistics staff sections to existing sustainment headquarters.With the publication of FM 3-0 and the follow-on release of FM 4-0, sustainers are undergoing a dramatic shift in the command relationships of sustainment forces at echelons above the BCT. That shift is a reflection of the new threat and operational environment. The previous relationships did not give warfighters the ability to fully integrate sustainment and rapidly weight the battle in complex large-scale combat operations.There are a number of challenges we are working our way through as we implement these changes, but success in the next fight depends on sustainers being able to effectively employ new command relationships to sustain the battle.-------------------- Maj. Gen. Rodney D. Fogg is the commander of Combined Arms Support Command and the Sustainment Center of Excellence at Fort Lee, Virginia. He holds master's degrees in logistics management and strategic studies, and he is a graduate of the Quartermaster Officer Basic and Advanced Courses, the Command and General Staff College, and the Army War College.Lt. Col. Hugh H. "Hank" Coleman III is a doctrine developer in Combined Arms Support Command's G-3/5/7. He has a bachelor's degree in business administration from Presbyterian College, a master's degree in transportation and logistics from North Dakota State University, and a master's degree in finance from the University of Maryland University College. He is a graduate of the Combined Logistics Captains Career Course and the Command and General Staff College. -------------------- This article was published in the January-March 2019 issue of Army Sustainment.