Over the past two years, Operations Group Sierra at the Mission Command Training Program has witnessed units struggling with command and support relationships. Expeditionary sustainment commands (ESCs) and sustainment brigades participating in warfighter exercises have dealt with their own doubts about command and support relationships as well as those of the corps and divisions they supported.

Throughout various commands and branches across the Army, it is quite evident that a clear understanding of command and support relationships simply does not exist. While there is no doctrinal right answer when it comes to command and support relationships between sustainment units and maneuver commanders, it is important for everyone to understand the pros and cons of each type of relationship.


Commanders drive the operations process and provide planning guidance to staffs as they develop orders and formulate plans for future operations. In order to achieve desired outcomes, staffs organize units by task and purpose, resulting in altered command and support relationships from the corps to the battalion level.

As courses of action develop and wargaming commences, unit roles and responsibilities change by sequence and phase. Annex A (task organization) of an operation order typically highlights these changes by phase, but all too often these nuances get lost in the parallel planning efforts at each echelon of command. Combat support and sustainment units are affected the most by these relationship changes.

The success of any operation hinges on clearly defined and well-understood command and support relationships. Often, units within a particular formation are unclear about the command and support relationships for a given operational phase. This lack of knowledge and understanding is even more pronounced when it comes to sustainment operations that support a maneuver commander. The confusion hinders mission success at a time when it is needed most.

In a briefing to students at the Army Command and General Staff College in August 2017, Maj. Gen. Paul Hurley, the commander of the Combined Arms Support Command, reiterated the trends our combat training centers see at echelons above brigade. He identified the misunderstanding of command and support relationships as a recurring shortcoming among training audiences. Hurley pointed out that units struggle with arraying their forces based on the defined relationship. He said units also struggle with how to effectively visualize the assigned task and purpose of subordinate units and forces they influence within support relationships.

Appendix B of Field Manual 6-0, Commander and Staff Organization and Operations, says that clear command and support relationships are necessary when task organizing for any operation. It goes on to say that command and support relationships establish responsibilities and authorities between supported and supporting units and that knowing what each command and support relationship means allows commanders to effectively organize their forces.

In the most basic sense, Field Manual 6-0 says that command relationships define command responsibility and authority while support relationships define the desired purpose, scope, and effect when one capability supports another. In some cases, a command relationship is not appropriate, and commanders may determine that a support relationship is more beneficial. This might occur when the command-level technical and tactical expertise resides in the supporting unit and not the supported unit. This may also happen when the supporting unit has more than one customer and must internally prioritize support efforts.


There are five Army command relationships: organic, assigned, attached, operational control (OPCON), and tactical control (TACON). (See figure 1.)

ORGANIC. Organic forces are those assigned to and forming an essential part of a military organization as listed in its table of organization. If temporarily task-organized with another headquarters, organic units return to the control of their organic headquarters after completing the mission.

ASSIGNED. Assigned units are placed in an organization relatively permanently. Unless specifically stated, this relationship includes administrative control.

ATTACHED. Attached units are placed in an organization temporarily.

OPCON. OPCON is the authority to perform the functions of command over subordinate forces including organizing and employing, assigning tasks, designating objectives, and giving authoritative direction necessary to accomplish the mission.

TACON. TACON is the authority over forces that is limited to the detailed direction and control of movements or maneuvers within the operational area necessary to accomplish missions or tasks assigned. TACON does not provide authority to change organizational structure or direct administrative and logistics support.


The four Army support relationships are direct support, general support, reinforcing, and general support-reinforcing (GSR). (See figure 2.) There is no command authority in support relationships, and they are normally established when subordinating one unit to another is inappropriate.

DIRECT SUPPORT. Direct support is a relationship requiring a force to support another specific force and authorizing it to answer directly to the supported force's request for assistance. A unit assigned a direct support relationship retains its command relationship with its parent unit, but it is positioned by and has priorities of support established by the supported unit.

GENERAL SUPPORT. General support is given to the supported force as a whole and not to any particular subdivision. Units assigned a general support relationship are positioned and have priorities established by their parent units.

REINFORCING. Reinforcing is a support relationship requiring a force to support another supporting unit. Only like units can be given a reinforcing mission. A unit assigned a reinforcing support relationship retains its command relationship with its parent unit but is positioned by the reinforced unit. A unit that is reinforcing has priorities of support established first by the reinforced unit and then by the parent unit.

GSR. GSR is a support relationship assigned to a unit to support the force as a whole and to reinforce another similar type of unit. A unit assigned a GSR support relationship is positioned and has priorities established by its parent unit and secondly by the reinforced unit.


Despite these explicit definitions, units inevitably will be confused or misinterpret the definitions. And as mentioned before, the relationship between maneuver and sustainment commanders is not explicitly defined in Army doctrine. It is not necessarily about what is right and wrong; it is more about understanding what each command and support relationship means and clearly conveying that to all units involved during planning and execution.

For Operations Group Sierra, the three most commonly used relationships over the past two years have been OPCON, direct support, and general support. As mentioned, OPCON is a command relationship and direct support and general support are support relationships. All three proved equally effective at one time or another, but there were also some hiccups with each along the way. Three examples stick out from the past two years of warfighter exercises.

The first example involved a sustainment brigade in a general support role to a division and the corps enablers located in that division's area of operations. As the division became the main effort during phase III, it ordered the sustainment brigade to relocate two of its combat sustainment support battalions (CSSBs), and make class V (ammunition) and class VII (major end items) the priorities for forward movement.

According to doctrine, when in general support, the parent unit (in this case the ESC) retains the authority to position forces and set priorities. So, while the need to reposition the CSSBs and prioritize class V and class VII made sense to the division and the sustainment brigade's role in supporting the division, it did not fit the ESC's overall concept of sustainment.

The sustainment brigade was in a general support role to the division and still had a general support responsibility to corps enablers. Therefore, the ESC had to be the one to make the call. In this case, repositioning the CSSBs hindered the overall sustainment operation, so the ESC denied it. The prioritization of class V and class VII made sense though, so the ESC published an order making it official for the sustainment brigade.

In another example, a sustainment brigade was in direct support to a division with a general support role to corps enablers in the division's area of operations. During phase III, the division commander wanted to task-organize the sustainment brigade to ensure his combat brigades were adequately supported at a river crossing.

Members of both the sustainment brigade and division staff spent hours developing a plan and producing orders to make it happen. It was not until the plan reached the sustainment brigade deputy commander that they all realized the division did not have the authority to task-organize the sustainment brigade. That inherent responsibility lies with the sustainment brigade's parent unit (again, the ESC). While the plan to task-organize the sustainment brigade seemed logical to those in the sustainment brigade and the supported division, the ESC disagreed because of the general support role the sustainment brigade still had to corps enablers in its area of operations.

In the third example, a corps issued a fragmentary order prior to the start of phase III dictating that a sustainment brigade operate under the OPCON of the division. This effectively established a command relationship between the sustainment brigade and the division, which was different from previous warfighter exercises. This command relationship created efficiencies in the execution of support to the maneuver commander, but it also created unique challenges in the sustainment brigade's relationship with the ESC.

For example, the sustainment brigade was more closely integrated into support area operations in the division support area. At one point, the sustainment brigade S-3 co-hosted the support area command post briefings with the maneuver enhancement brigade S-3 to the deputy commanding general for support. These briefings typically generated synchronized movements in the support area and better security than observed in previous exercises.

Unfortunately, the gains in the tactical arena created gaps and seams in the operational sustainment arena. Authorities and overall visibility of class VII replenishment from the ESC to the sustainment brigade became fraught with misinformation and lacked integration. The collaborative boards, bureaus, centers, cells, and working groups that ordinarily occur between commands with an organic command relationship did not occur with the same frequency in this general support relationship.

In this case, integration with the ESC presented a larger challenge caused by the change from a command relationship to a support relationship. The sustainment brigade concept of sustainment called for echeloning support and synchronizing forward-bounding support areas. While the operation presented issues that stymied the ability to do this concurrently, the division adequately synchronized these moves internally. However, echelon-above-division synchronization occurred in a less predictable, ad hoc way. The division could have benefited from additional ESC touchpoints to synchronize inbound sustainment.

In this same situation, the ESC was under the OPCON of the corps. This relationship was very beneficial in that it helped integrate planning efforts and nest decision points both before and during operations. However, during execution, the ESC had a difficult time seeing the capabilities of its subordinate organizations.

The OPCON relationship between the sustainment brigade and the division also meant that the ESC could not task-organize as it saw fit. This limited the ESC's span of control and left many assets within that sustainment brigade underused and other sustainment brigades scrambling for assets they did not have.

As formal command relationships become less common among sustainment organizations, higher-level headquarters can (and should) leverage policy to clarify requirements for supported organizations.

In all three of Operations Group Sierra's examples, a lack of understanding and knowledge of command and support relationships caused confusion. Staff work was wasted and momentum was lost during operations because of the confusion. If planners and staff members understood their left and right limits when it came to command and support relationships, these incidents may not have occurred.

Going forward, it is important for all commanders and staff officers to understand what each command and support relationship means and ensure the relationships established are appropriate and optimal for the given operation. It may also be beneficial for the Army to take a hard look at what doctrine says and perhaps codify what command and support relationships between sustainment and maneuver commanders will look like in the future.

Lt. Col. Justin M. Redfern is the chief of the Integration Division, Combat Training Center Directorate, Combined Arms Center-Training. He holds a master's degree in global supply chain management from the University of Kansas.

Maj. Aaron M. Cornett is an instructor in the Department of Logistics and Resource Operations at the Army Command and General Staff College. He holds a master's degree in journalism from the University of Kansas.
This is an Army Sustainment magazine product.