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Reconstituting Combat Power in Large-Scale War

A Layered Approach

 

Col. Chad M. Pillai, US Army
Lt. Col. Sam Rosenberg, PhD, US Army
Lt. Col. Brandon Schwartz, US Army
Maj. Phillip J. Hoying, US Army Reserve
Capt. Justin Senecal, US Army

 

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For the past twenty years, the US Army has built its force around predictable rotations and limited wars. Large-scale combat operations, with their corresponding high casualty rates, received limited attention. But Russia’s invasion of Ukraine changed that. It revalidated that modern combat consumes people, materiel, and munitions at rates that can break formations. It reminded the world that armies can break under pressure, and they must find ways to rebuild while fighting, a process called reconstitution.

Reconstitution has long been an Army doctrinal concept, but in practice, it is rarely planned or resourced in advance. Despite publishing new reconstitution doctrine in 2021, the US Army lacks a clear operational-level model for reconstituting formations during combat.¹ The core challenge is how theater armies generate, restore, and integrate combat power while sustaining momentum against a peer adversary.

To address this gap, US Army Europe and Africa (USAREUR-AF) developed a theater-level reconstitution concept that serves as the foundation for this article. The concept emerged from recent operational planning and exercise analysis and represents the first detailed framework in decades focused on rebuilding combat power during large-scale combat operations. Designed for theater armies, it provides a practical model for regenerating divisions. The concept integrates sustainment, training, personnel, and multinational support into a single campaign function, marking a shift from theoretical discussion toward executable planning guidance for restoring combat power while in conflict.

This article builds on the USAREUR-AF concept and offers a layered model of reconstitution, grounded in historical US experience in Europe and informed by modern lessons from Ukraine. It is written for planners and commanders who must think through how to keep formations in the fight. Reconstitution preparation cannot wait for the next war. It must be part of how we prepare now.

Doctrinal Shortfalls

Doctrine is the foundation of organizing, training, and educating units and soldiers for the next fight. The Army formalized its approach to reconstitution with the publication of Army Techniques Publication (ATP) 3-94.4, Reconstitution Operations, in May 2021. This manual reimplemented and updated previously rescinded reconstitution doctrine, which was last published in Field Manual (FM) 100-9, Reconstitution, in 1992. ATP 3-94.4 defines reconstitution as “an operation that commanders plan and implement to restore units to a desired level of combat effectiveness commensurate with mission requirements and available resources.”² It recognizes that large-scale combat will cause losses far beyond what the Army has experienced in generations and emphasizes the importance of planning for reconstitution to enable commanders to retain the initiative. The manual covered a significant gap in Army doctrine and effectively introduced clear terminology, reconstitution principles, major elements of reconstitution, and considerations for planning and executing reconstitution operations. The publication of ATP 3-94.4 also represented an important step in the Army’s approach to describing how to execute multidomain operations.

However, ATP 3-94.4 is still insufficient to meet the Army’s doctrinal needs for reconstitution. The manual lacks echelon-specific guidance and contains no sections describing reconstitution responsibilities at the division, corps, or theater army levels. This gap might be acceptable if echelon manuals addressed reconstitution elsewhere, but associated ATPs and FMs barely reference it. As a result, while ATP 3-94.4 effectively introduces principles and terminology, echelons division and above are left to develop ad hoc concepts and techniques for reconstitution operations.

Second, ATP 3-94.4 does not include a holistic concept of reconstitution during large-scale combat operations. Doctrine would benefit from having an integrated concept that describes how reconstitution simultaneously occurs across echelons over the entire period of a conflict, overlaid on the strategic and operational frameworks. It should include echelon responsibilities, functions, key tasks, purposes, and dedicated force structures arranged by time and space. This detail is entirely absent from ATP 3-94.4. There are no figures, tables, or sections to illustrate or describe this holistic concept. There is virtually no mention of the strategic or operational frameworks, or examples of a soldier or piece of equipment moving through the process. There is also an absence of a discussion about routine reconstitution, as opposed to surge requirements. This gap in doctrine results in insufficient knowledge across the institutional and operational Army of how the multitude of disparate Army enterprise commands synchronize to reconstitute combat forces during conflict.

Third, ATP 3-94.4 describes unrealistic expectations about the security conditions of regenerating units. Regeneration is “the rebuilding of a unit through large-scale replacement of personnel, equipment, and supplies, including the reestablishment of essential command and control and the conduct of mission-essential training for the unit.”³ Regeneration is the most complex of the elements of reconstitution, and it is the focus for reconstitution planning at corps and theater army echelons since it is the most challenging problem. ATP 3-94.4 states that “regeneration usually occurs … out of contact with enemy forces,” and that “units cannot successfully regenerate while in direct or indirect fire contact.”⁴ It also states that “planners integrate security for regeneration actions into the overall rear operations plan [emphasis added].”⁵

While these are ideal conditions, it gives Army forces the false impression that regeneration activities must occur in relative sanctuary, out of contact with enemy forces and in the rear area. In reality, the US Army has historically conducted regeneration along the front line, often because of a lack of replacement divisions or corps to allow for a complete withdrawal. For example, the 28th Infantry Division regenerated along the front line after the Battle of Schmidt in 1944, simply moving to a quieter sector while continuing to conduct defensive operations.⁶ Army doctrine should reflect the reality that commands must plan for regeneration near the forward line of troops, potentially exposed to all forms of contact.

Army doctrine should focus on the theater army as the key headquarters for synchronizing reconstitution of Army forces in a combatant commander’s area of responsibility. The theater army is best positioned to do this because of its unique set of responsibilities, authorities, and capabilities. The theater army’s primary role is Army Service component command for their supported combatant command.⁷ In that role, the secretary of the Army delegates many service-related legal obligations and executive agent responsibilities to the theater army commander through administrative control authority.⁸ This includes the responsibility and authority for organizing, supplying, equipping, and training all Army forces operating in an area of responsibility, all of which are key elements of reconstitution operations. To do this, the Army provides theater armies unique capabilities and formations to ensure their ability to meet their service obligations. Examples include the theater sustainment command and the theater gateway personnel accountability team.⁹

Theater armies are also ideal for synchronizing reconstitution because they conduct force tailoring. When force tailoring, they determine the right composition and deployment sequence of Army forces, which allows them to organize theater-level reconstitution capabilities.¹⁰ Additionally, as the highest Army echelon in an area of responsibility, theater armies routinely coordinate with the joint force and the broader Army enterprise, all of which must be synchronized to support reconstitution operations. It is this unique combination of responsibility, authority, and capability that allows the theater army to receive and integrate replacement personnel and equipment, secure and organize them, train the personnel, and transport them to subordinate tactical formations for their employment.

At USAREUR-AF, we built on the foundational ideas in ATP 3-94.4 and addressed some of its shortfalls to develop a theater-level reconstitution concept. This concept integrates reconstitution into operational plans and enables phased regeneration across echelons. It is beginning to shape how subordinate commands train, exercise, and prepare. While doctrine offers an important starting point, evolving threats and operational realities demand a more expansive model that treats reconstitution as an essential function supported by military, civilian, and multinational capabilities.

Defining Layered Reconstitution

Reconstitution is a continuous wartime function related to administrative control authority. Layered reconstitution provides a model that spans echelons, timelines, and authorities.

Layered reconstitution can be visualized as a sequential flow model, as depicted in the figure. In this process, “Initial Military Degradation” (the input) is processed through five distinct layers to create “Restored Military Strength” (the output). These layers are tactical reconstitution, operational reconstitution, multinational support, industrial and civilian mobilization, and national mobilization. Each successive layer represents a broader scale of effort and authority required to regenerate combat power. While depicted sequentially as a flow, these layers can be activated in parallel and must reinforce one another to be effective.

Tactical reconstitution. The first layer is military reorganization. It occurs at the tactical level of warfare and is directed by division and corps, usually at echelons below brigade. At the tactical level, reconstitution focuses on restoring combat power rapidly under pressure. It primarily employs reorganization techniques—realigning command and control, redistributing supplies, and combining degraded elements to sustain the fight—and includes redistribution and incremental regeneration, where individual personnel and items of equipment are replaced in small numbers to maintain combat effectiveness. These efforts often occur near the forward line of troops and depend on subordinate initiative and local sustainment. Commanders use this layer to stabilize formations and retain combat effectiveness to maintain tempo.

Operational reconstitution. The operational layer expands the scope of effort to division, corps, or theater levels. Here, reconstitution involves full-scale regeneration, from brigades through divisions. Unique to the theater army is the Army support to other Services requirement that could require the Army to support the joint force reconstitution efforts for items like ground vehicles, basic armaments, and certain helicopters.¹¹ This process requires protected time, space, and logistics to be effective. It includes integrating replacements, retraining leadership teams, and restoring collective proficiency. Operational reconstitution also encompasses the synchronization of fires, sustainment, and replacement flows to ensure regenerated units return to the fight as combat effective formations. When properly sequenced with tactical actions, this layer transitions reorganization and incremental fixes into structured regeneration of combat units.

Multinational support. This layer enables reconstitution through allied and partner contributions. These may include donated equipment, partner-led training programs, access to staging or maintenance areas, or the backfilling of coalition missions. Ukraine offers a powerful example of this approach. NATO partners have supported Ukraine’s regeneration through modular training hubs, logistics corridors, and direct materiel support.¹² In a future conflict, the United States may depend on partners in similar ways. Nations such as Poland, which have procured large numbers of tanks and built advanced maintenance infrastructure, could expand reconstitution capacity within Europe. Rather than returning damaged equipment to the United States, the Army could leverage European facilities—whether Polish, German, or other NATO allies operating Abrams or similar systems—for forward maintenance, repair, and regeneration. These arrangements should be built into planning, exercises, and foreign military sales. This layer broadens the reconstitution base, reinforces legitimacy, and distributes burden across the coalition.

Industrial and civilian mobilization. The next layer includes the defense industrial base, commercial logistics, medical systems, and civilian infrastructure-and-technology partners. It also encompasses societal contributions such as nongovernmental organizations, humanitarian organizations, private donors, and host-nation institutions that sustain rear-area operations. In Ukraine, this layer has taken the form of widespread public engagement, from civilian crowdfunding for drones and vehicles to private-sector production of critical components. These efforts extend state capacity and sustain combat power over time. This layer recalls World War II, when the United States became the “Arsenal of Democracy,” rebuilding vast military capability through total industrial mobilization.¹³

For the United States and NATO, effective reconstitution at scale will depend not only on industrial output but also on society’s ability to mobilize through preestablished contracts, legal authorities, and civil-military coordination. This layer provides endurance in protracted conflict and depth when traditional systems are stretched.

National mobilization. The last layer broadens reconstitution to the strategic level. It includes activating reserve components, expanding training pipelines, reallocating prepositioned stocks, and implementing emergency personnel policies. These actions are directed by Headquarters, Department of the Army (HQDA), and national-level institutions and often require interagency coordination. Mobilization must be anticipated and synchronized with campaign design to ensure that fresh formations arrive in time to sustain operational tempo. This layer rebuilds the depth of the force and provides the strategic resilience necessary to absorb losses over time.

Linking the Layers of Reconstitution

While the individual layers define the “what” and “where” of rebuilding combat power, the operational challenge lies in the “how,” specifically how these disparate efforts are synchronized across time, space, and authority. Each layer within the reconstitution framework operates on its own timeline and under different command authorities, yet they are interdependent. Tactical reorganization and incremental regeneration depend on operational synchronization, partner contributions, industrial throughput, and national replacement pipelines. The system must be planned and visualized as a whole. Its value lies in its depth, flexibility, and redundancy. When integrated into plans, exercises, and operational design, the layered model enables the Army to restore combat power in time, under pressure, and at scale. Reconstitution is therefore an ongoing system of interconnected functions rather than a single event. A layered approach provides a practical framework for sustaining fighting strength in protracted conflict.

Technology and Agile Sustainment

To enable this integration, the Army must leverage the connective tissue of modern capability. Optimal layered reconstitution will depend on how effectively the Army harnesses emerging technologies to create an agile sustainment enterprise. Predictive logistics enabled by artificial intelligence can anticipate demand, prioritize recovery and repair, and optimize resupply in near real-time. Advanced command-and-control tools can synchronize sustainment flows with operational tempo, providing commanders visibility on when and where regenerated forces will reenter the fight. Additive manufacturing, automation, and data-driven maintenance can accelerate forward repair and reduce dependence on extended supply lines. Together, these technologies enable faster coordination across tactical, operational, industrial, and national layers.

Historical Case Studies in Reconstitution

While the layered reconstitution model provides a conceptual framework, its value rests on whether it explains real outcomes in war. The following historical cases test the model against operational reality. Each case illustrates how access to, or isolation from, different layers of reconstitution shaped a formation’s ability to recover combat power while fighting. Together, they demonstrate that reconstitution success depends less on national capacity alone than on the ability to connect tactical forces to operational, national, and industrial systems under pressure.

The historical record demonstrates this problem across eras. The cases that follow examine the 28th Infantry Division’s incremental regeneration under fire, the 7th Armored Division’s operational recovery after Saint Vith in the Battle of the Bulge, and Ukraine’s contemporary multinational effort to regenerate combat power at scale.

28th Infantry Division at Schmidt (1944): Incremental regeneration under fire. By autumn 1944, the 28th Infantry Division, a Pennsylvania National Guard formation, had endured months of attritional fighting across France and Belgium. After a brief rest and refit, the division received several thousand replacements to rebuild from losses sustained during the Normandy breakout. In early November, V Corps ordered the division to seize the village of Schmidt in the Hürtgen Forest, an operation meant to open the route to the Roer River dams. The forest, however, was steep, heavily mined, and saturated with preregistered German artillery fire that nullified US advantages in armor and airpower.¹⁴

Although reinforced on paper, the 28th was not truly reconstituted. Replacements were integrated individually without retraining or team rebuilding. When the attack began on 2 November, the division’s three regiments advanced along narrow trails that funneled movement and communications. Within days, the 112th Infantry Regiment was isolated and surrounded in Schmidt, while the 109th and 110th Regiments struggled to maintain contact and resupply. Division headquarters attempted incremental regeneration, pushing new personnel forward and redistributing ammunition and supplies under fire.¹⁵ These actions preserved a temporary defense but did not restore cohesion or combat rhythm. By mid-November, the 28th had lost nearly half its strength—over six thousand soldiers—and was withdrawn from the line.¹⁶

This outcome was not due to a lack of national capacity. In 1944, the United States was fully mobilized with massive replacement depots, industrial output, and a functioning strategic sustainment base. Yet the tactical situation of the 28th—fighting in dense forest without relief or maneuver space—prevented it from accessing higher layers of reconstitution. The division could not rotate units for retraining, receive replacements in mass, or leverage industrial repair support. Its isolation confined it to the tactical layer alone, attempting to rebuild while under fire.

The 28th Infantry Division’s dilemma illustrates the limits of incremental regeneration when only the tactical layer is active. Without sufficient operational or national linkage during this particular engagement, replacements and supplies could not generate true combat power. Even within a fully mobilized nation, the absence of protected time and space for the division prevented higher layers from engaging, resulting in tactical exhaustion and organizational collapse.

7th Armored Division after Saint Vith (December 1944–January 1945): Operational regeneration and systemic recovery. When Germany launched its Ardennes counteroffensive, eventually known as the Battle of the Bulge, on 16 December 1944, the 7th Armored Division, commanded by Brig. Gen. Robert W. Hasbrouck, was ordered south from the Netherlands to block the German advance at Saint Vith, Belgium. Arriving piecemeal, its combat commands fought dispersed defensive actions against superior German armored forces. For nearly a week, the division held successive positions under intense pressure from multiple panzer corps. Supply routes were cut, communications were intermittent, and weather precluded air support. Despite heavy losses and partial encirclement, the division’s delaying actions disrupted the German timetable and bought critical time for Allied reinforcements to organize along the Meuse River. On 23 December, with encirclement imminent, Hasbrouck executed a disciplined withdrawal westward under fire, preserving the nucleus of the division for regeneration.¹⁷

After executing this breakout from Saint Vith, the 7th Armored Division withdrew west of the Salm River.¹⁸ The division had maintained its command structure and 70 percent of its personnel, but the “Lucky Seventh” and its supporting units suffered steep losses during the battle. Historian Hugh Cole notes the division lost fifty-nine medium tanks, twenty-nine light tanks, and twenty-five armored cars.¹⁹ The 814th Tank Destroyer Battalion, a key 7th Division attachment, lost fourteen of its thirty-five destroyers.²⁰ When accounting for all forms of attrition, including disease and combat wounds, the division suffered nearly 20 percent casualties.²¹ Because these losses were concentrated in the fighting ranks, the division entered January with only 70 percent of its adequate combat personnel and 56 percent of its authorized medium tanks.²² For the next month, the division undertook one of the most successful operational-level reconstitutions of the European campaign.

Upon reaching assembly areas near Spa and later in northern France, Hasbrouck and his staff reestablished command and control, initiating a phased regeneration plan. The division’s subordinate tactical units, known as Combat Commands A, B, and R, were reorganized into provisional training groupings, allowing subordinate leaders to rebuild teams while maintaining accountability of personnel and materiel.²³ In total, the First Army, who organized much of the logistical work required to reconstitute the 7th Armored Division, brought a total of 168 Sherman tanks into full operational service, bringing the division up to better than 100 percent strength.²⁴

Replacement flows from US depots in Normandy began arriving by early January. These were integrated not as individuals but as complete tank crews, gun sections, and infantry squads—an early recognition that cohesion mattered more than raw numbers.²⁵ Short, high-intensity retraining cycles emphasized gunnery, maneuver in snow and mud, and rapid combined-arms coordination. Within three weeks, the division had regained near-full combat strength.²⁶ On 20 January 1945 it reentered the line, spearheading the counteroffensive to retake Saint Vith, symbolically completing its “redemption,” as historian Gregory Fontenot describes.²⁷

The division’s rapid recovery was made possible by the depth of the Allied replacement and sustainment system. Ordnance depots in France accelerated production of spare parts; rail and truck convoys from Antwerp delivered tanks and artillery drawn from national prepositioned stocks. Reinforcements flowed through the replacement and training system that linked continental US training bases with European Theater depots, exemplifying national-level mobilization feeding operational recovery. Industrial capacity ensured that every vehicle lost at Saint Vith could be replaced within weeks.

The 7th Armored Division’s experience after Saint Vith demonstrates how operational, national, and industrial layers can align to regenerate a division within an ongoing campaign. Tactical reorganization during the defense preserved the nucleus of leadership; operational planning after withdrawal rebuilt subunits as coherent teams; national and industrial systems replenished equipment and personnel. The synchronization of these layers turned near-destruction into renewed offensive capability within a month. The case illustrates that even in a fully mobilized war, success depended on the ability to translate national capacity into operational effect through flexible command, protected time, and disciplined sequencing.

Ukraine (2022–Present): Layered reconstitution at scale. The United States does not need to rely solely on reconstitution case studies from World War II but can instead turn to a modern example in Europe. Ukraine’s defense against Russia since 2022 represents the most comprehensive example of layered reconstitution in modern warfare. Facing enormous attrition across multiple fronts, Ukraine has repeatedly rebuilt combat power through a blend of tactical adaptation, multinational assistance, industrial improvisation, and effective, albeit severely restricted, national mobilization.

At the tactical level, Ukrainian brigades have demonstrated significant adaptability while in contact. Rather than conducting full-scale withdrawals for reconstitution, commanders frequently task-organize: depleted battalions are cross-attached to holding units, and mobilized personnel are integrated directly into veteran formations to maintain forward combat power. Units maximize short operational pauses for local recovery and refresher training to reconstitute fighting teams.

At the operational level, Ukraine relies heavily on multinational support to regenerate forces. Partner nations have established a distributed training architecture outside Ukraine that provides protected time and space for unit regeneration and skill development. This includes the United Kingdom’s Operation Interflex, the US-led Security Assistance Group–Ukraine and Joint Multinational Training Group–Ukraine in Germany, and the European Union Military Assistance Mission operating across Germany and Poland.²⁸ These initiatives provide modular training, leader development, and collective task preparation at scale. In parallel, NATO, through the establishment of the NATO Security and Assistance Training Ukraine, has expanded its security assistance and training framework to enable sustained logistics support and coordination across the alliance.²⁹

At the national level, Ukraine has conducted successive mobilization waves but now faces mounting constraints. In April 2024, Ukraine’s mobilization reforms reduced the minimum mobilization age to twenty-five, while the government has also pursued programs to recruit younger volunteers (eighteen to twenty-four) under contract.³⁰

Legal and political limits on recruitment age have narrowed the available pool of trained personnel and contributed to an aging fighting force with an average age of over forty years old.³¹ As manpower pressures grow, the state increasingly depends on civilian and industrial surrogates to fill capability gaps. Civilian engineers and entrepreneurs have developed unmanned systems; field-repair workshops; and crowdfunding campaigns that deliver drones, vehicles, and critical components to frontline units.³² These initiatives represent an emergent form of industrial and societal reconstitution, expanding endurance even as the human base contracts.

Technology has played an important role in linking these layers of reconstitution. Digital command-and-control tools, commercial satellite communications, and distributed data networks have allowed tactical units in contact to remain connected to operational headquarters, multinational training pipelines, and logistics nodes outside the country. These networks enable near–real-time transmission of battlefield requirements, damage assessments, and personnel needs, allowing higher echelons and external partners to prioritize training rotations, equipment repair, and replacement flows. At the industrial and societal level, civilian-developed software tools, unmanned systems, and distributed manufacturing and repair networks have shortened the cycle between battlefield loss and restored combat capability. Rather than constituting a separate layer, technology in Ukraine functions as connective tissue across the system, translating multinational, industrial, and societal capacity into tactical combat power.

Despite these innovations, friction persists in Ukraine’s reconstitution effort. Replacement training remains uneven, equipment delivery timelines lag, and continued losses among experienced soldiers degrade unit quality faster than it can be restored.³³ Absent further mobilization, Ukraine faces growing difficulty sustaining its defensive capabilities over the long term.

At the same time, Ukraine’s experience activates all five layers—tactical, operational, multinational, industrial and civilian, and national mobilization—simultaneously. This integration has allowed Ukraine to sustain combat power longer than initial assessments predicted. Yet restrictions on manpower mobilization create asymmetry across the system. While industrial and multinational support remain robust, the national layer’s human component is stretched thin. Ukraine’s approach demonstrates both the feasibility and the limits of layered reconstitution under the extreme conditions of modern high-intensity warfare.

Across these three cases, a consistent pattern emerges—effective reconstitution requires a layered approach leveraging all layers. The 28th Infantry Division was confined largely to the tactical layer by operational conditions and lacked access to higher-level reconstitution mechanisms, preventing meaningful recovery. The 7th Armored Division engaged three layers and achieved rapid regeneration through operational initiative and national depth. Ukraine activates all five layers, demonstrating how a modern state can sustain combat power through distributed, multinational systems even under severe strain. The lesson is clear: reconstitution is most effective when all layers are planned, linked, and exercised together.

Recommendations and Implications

The Army and the joint force should treat reconstitution as a function at each echelon, planned and practiced in advance. To achieve this, the institution should pursue six mutually reinforcing lines of effort: update doctrine and regulations, wargame and experiment at scale, connect the layers through technology, build multinational and industrial capacity, mobilize and train personnel differently, and institutionalize command and control for reconstitution.

1. Update doctrine and enforce regulations. The Army should revise ATP 3-94.4 and ATP 3-93 to define layered reconstitution as a continuous wartime function that spans tactical, operational, national, and industrial domains. This update should assign the theater army formal responsibility for planning and synchronizing reconstitution across personnel, equipping, and training pipelines. Doctrine should expand to cover civilian and industrial mobilization, multinational repair and training networks, and the integration of emerging technologies.

Future doctrine must also prepare commanders to rebuild units under conditions of shortage. When tanks, infantry fighting vehicles, or key components are unavailable, commanders may need to regenerate units as hybrid combined-arms task forces that integrate available systems, unmanned platforms, and autonomous logistics. The focus should be on restoring combat effectiveness and adaptability rather than replicating prewar structures.

The Army also needs to enforce reconstitution-related regulations. In particular, Army Regulation (AR) 500-5, Army Mobilization, identifies the Army G-3/5/7 as the enterprise integrator for reconstitution. It specifically assigns responsibility for “policy, guidance, and planning assumptions for the … reconstitution of Army forces.”³⁴ Theater armies do not have the authority or expertise to develop reconstitution plans that involve the entire Army enterprise, creating a dependency on the Army G-3/5/7’s execution of its AR 500-5 responsibilities.

For example, while a theater army can establish sites to refit armored units, it lacks the authority to surge production within the organic industrial base or redirect the global flow of major end items. Furthermore, while USAREUR-AF can synchronize the retraining of its own brigades, only the G-3/5/7 has the enterprise-wide visibility to prioritize those requirements against the needs of other combatant commands. This structure allows theater armies to focus on the operational art of reconstitution while leveraging the G-3/5/7’s authority to mobilize and allocate resources at scale.

2. Wargame and experiment at scale. Doctrine alone cannot prepare the force to regenerate while fighting. Reconstitution must be practiced in exercises, simulations, and theater-level experiments that stress commanders and staffs.

At the HQDA level, the Army should lead a campaign of learning that tests reconstitution as an operational function integrated with strategic commands and capabilities. Measures of effectiveness should include time to rebuild a brigade, percentage of combat systems recovered, and degree of unit cohesion retained. At the theater level, exercises such as DEFENDER Europe should include realistic reconstitution injects—losses, replacements, industrial surges, and partner support—to test decision-making and synchronization under pressure.³⁵

These events should involve industry, combatant commands, the Defense Logistics Agency, NATO’s Support and Procurement Agency, joint enabling commands (e.g., Transportation Command), and national sustainment commands. Practicing these interactions in peacetime will reveal friction points in authorities, contracting, and information sharing before a crisis occurs.

3. Connect the layers through technology. The Army should invest in technologies that make layered reconstitution faster and more reliable. Predictive logistics powered by artificial intelligence can anticipate demand and prioritize recovery and repair efforts. Additive manufacturing and automated construction can produce parts and facilities forward, reducing dependence on extended supply lines. Autonomous convoys, unmanned resupply drones, and condition-based maintenance systems can move materiel and sustain readiness while limiting risk to personnel.³⁶

These tools will reach their potential only if they are integrated through a secure, data-centric sustainment network. The Army should build government-owned data architectures that connect sensors, depots, and decision tools across echelons and allied networks. This would allow commanders to visualize reconstitution as a dynamic system that aligns people, equipment, and time to restore combat power more quickly than an adversary.

4. Build multinational and industrial capacity before the fight. Effective reconstitution during war depends on relationships established in peace. The United States and its allies should prenegotiate maintenance and logistics arrangements that allow forward repair and regeneration across borders. Polish, German, and other European maintenance hubs operating US equipment could serve as central nodes for coalition-wide reconstitution. Framework contracts, shared stockpiles, and emergency authorities established beforehand would allow immediate action once losses occur.

Exercises should also test the role of partners and industry in reconstitution—how they deliver spare parts, train replacement crews, or assume coalition missions while US units rebuild. Building this network in advance strengthens deterrence by showing that NATO can regenerate as well as fight.

5. Mobilize and train people differently. Regeneration depends on cohesive teams as much as on materiel. The Army should emphasize replacements by crews, squads, and teams rather than individuals to preserve leadership continuity and proficiency. Reserve Component maintainers, medics, and transporters should be identified for rapid mobilization, while emergency authorities should allow civilian technicians and allied contractors to support sustainment operations.

Training pipelines should become more flexible, using modular and short-duration courses to requalify personnel for hybrid organizations that combine legacy and modern systems. These adjustments will help the Army restore human capability at the same pace as materiel recovery.

6. Institutionalize command and control for reconstitution. The Army should reestablish echelon above corps reconstitution force structure. Over the preceding decades, the Army periodically eliminated dedicated reconstitution force structure to harvest positions for use in more tactical formations. Over time, those individual decisions accumulated into the nearly complete removal of reconstitution-dedicated formations. This currently leaves theater armies with the requirement to develop ad hoc reconstitution force structure to manage the various reconstitution nodes. Reestablishing part of the eliminated reconstitution force structure would prepare theaters to handle the demands of large-scale combat operations.

In particular, the Army should reestablish replacement battalions. During World War II, in the European Theater of Operations, the US Army created a replacement command to synchronize, integrate, and manage all the various replacement (i.e., reconstitution) activities occurring in theater. The backbone of this system was the replacement battalion, which provided command and control over the activities at a particular reconstitution site. Replacement battalions were task-organized to purpose and generally included capabilities for node command and control and corresponding expertise for the purpose of the site, such as training or reception, staging, onward movement, and integration. They were then augmented with additional capabilities, such as postal, finance, and legal, to manage the flow of replacement personnel.

The current Army solution for replacement node command and control is the regional support group. The regional support group does not have the appropriate capability to organically run reconstitution nodes. They also do not have the associated mission essential tasks, which means they do not train for the reconstitution mission. Reestablishing replacement battalions, even at a reduced capacity, would greatly aid theater armies by having reconstitution-trained formations to manage individual nodes.

Conclusion

Reconstitution is a continuous function of warfighting that begins in contact and extends across the depth of the theater. Commanders who plan for it early preserve combat power, sustain tempo, and retain the initiative.

The layered model presented here provides the Army with a framework to do this systematically. It connects tactical reorganization, operational regeneration, national mobilization, and multinational-industrial support into a coherent system of endurance. When paired with emerging technologies—predictive logistics, additive manufacturing, and data-driven sustainment—it allows theater armies to restore combat power on timelines relevant to modern large-scale combat.

Implementing this approach will require institutional change. Doctrine must evolve, exercises must simulate loss and recovery under pressure (and integration of replacements), and partnerships with allies and industry must be formalized in advance. These steps transform reconstitution from an administrative function into an operational capability that strengthens deterrence and ensures resilience in protracted conflict.

Preparing to reconstitute is preparing to win. In future large-scale combat, success will belong to the side that can rebuild faster, smarter, and together.

The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Army, US Army Europe and Africa, the Department of War, or the US government.

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Notes

1. Army Techniques Publication (ATP) 3-94.4, Reconstitution Operations (US Government Publishing Office [GPO], May 2021), https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN32296-ATP_3-94.4-000-WEB-1.pdf.
2. ATP 3-94.4, Reconstitution Operations, 1-1.
3. ATP 3-94.4, Reconstitution Operations, 1-2.
4. ATP 3-94.4, Reconstitution Operations, 1-2, 1-4.
5. ATP 3-94.4, Reconstitution Operations, 3-2.
6. Edward J. Drea, Unit Reconstitution: A Historical Perspective (Combat Studies Institute Press, 1983), 50.
7. ATP 3-93, Theater Army Operations (US GPO, August 2021), 1-1, https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN33322-ATP_3-93-000-WEB-1.pdf.
8. Army Regulation (AR) 10-87, Army Commands, Army Service Component Commands, and Direct Reporting Units (US GPO, 2017), 2, https://armypubs.army.mil/epubs/DR_pubs/DR_a/pdf/web/ARN2541_AR10-87_WEB_Final.pdf.
9. ATP 4-93, Theater Sustainment Operations (US GPO, May 2023), 2-1–2-10; ATP 1-02, Theater-Level Human Resources Support (US GPO, January 2017), 3-6–3-10.
10. ATP 3-93, Theater Army Operations, 6-2.
11. Field Manual 4-0, Sustainment Operations (US GPO, March 2026), 22, 23, https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN46157-FM_4-0-000-WEB-1.pdf.
12. “NATO Security Assistance and Training for Ukraine,” Supreme Headquarters Allied Powers Europe, NATO, accessed 8 May 2026, https://shape.nato.int/nsatu. NATO operates exclusively on Allied territory and is not a party to the conflict.
13. Franklin D. Roosevelt, “Fireside Chat 16: On the ‘Arsenal of Democracy’” (speech, Miller Center, University of Virginia, 29 December 1940), https://millercenter.org/the-presidency/presidential-speeches/december-29-1940-fireside-chat-16-arsenal-democracy.
14. Thomas G. Bradbeer, Major General Cota and the Battle of the Huertgen Forest: A Failure of Battle Command? (US Army Command and General Staff College, 2023), 9–13.
15. Drea, Unit Reconstitution, 36.
16. Williamson Murray and Allan R. Millett, A War to Be Won: Fighting the Second World War (Harvard University Press, 2000), 461.
17. Hugh M. Cole, The Ardennes: Battle of the Bulge, United States Army in World War II (US Army Center of Military History, 1965), 393–422.
18. Robert W. Hasbrouck, “Distinguished Unit Citation [Recommendation for 7th Armored Division], June 27, 1947,” in The Seventh Armored Division in the Battle of St. Vith (Seventh Armored Division Association, 1948), 58.
19. Cole, The Ardennes: Battle of the Bulge, 422.
20. Gregory Fontenot, Loss and Redemption at St. Vith: The 7th Armored Division in the Battle of the Bulge (University of Missouri Press, 2019), 355, Kindle.
21. Fontenot, Loss and Redemption at St. Vith, 355.
22. 7th Armored Division, After Action Report, 7th Armored Division, Period 1-31 January, 1945, 2.
23. Cole, The Ardennes, 422; Donald P. Boyer, St. Vith: The Seventh Armored Division in the Battle of the Bulge, 17–23 December 1944: A Narrative After Action Report (Seventh Armored Division Association, 1947), 83, https://www.7tharmddiv.org/docrep/X-7AD-PUC.doc; “814th Tank Destroyer Battalion, ‘After Action Report December 1944,’” quoted in Fontenot, Loss and Redemption at St. Vith, 356, 384; 7th Armored Division, After Action Report, 7th Armored Division, Period 1-31 January, 1945, 1.
24. Fontenot, Loss and Redemption at St. Vith, 372.
25. Fontenot, Loss and Redemption at St. Vith, 369.
26. Fontenot, Loss and Redemption at St. Vith, 374–77.
27. Fontenot, Loss and Redemption at St. Vith, 384.
28. UK Ministry of Defence, “Operation Interflex Reaches Three-Year Milestone,” Government of the United Kingdom, 26 June 2025, https://www.gov.uk/government/news/operation-interflex-reaches-three-year-milestone; US Europe and Africa, “US Department of Defense Establishes Security Assistance Group-Ukraine in Wiesbaden” press release, 16 November 2022, https://www.europeafrica.army.mil/ArticleViewPressRelease/Article/3219717/press-release-us-department-of-defense-establishes-security-assistance-group-uk/; “Joint Multinational Training Group–Ukraine (JMTG-U),” 7th Army Training Command, accessed 27 April 2026, https://www.7atc.army.mil/JMTGU/; “Mission and Tasks of the Bundeswehr,” Bundeswehr, accessed 27 April 2026, https://www.bundeswehr.de/en/about-bundeswehr/mission-and-tasks-bundeswehr/germany-eumam-ua; “EU Military Assistance Mission in Support of Ukraine,” European Union, accessed 27 April 2026, https://www.eeas.europa.eu/eumam-ukraine_en.
29. “Joint Press Conference by the Chair of the NATO Military Committee, Admiral Rob Bauer, the Supreme Allied Commander Europe, General Christopher Cavoli and the Supreme Allied Commander Transformation, Admiral Pierre Vandier,” NATO, 16 January 2025, https://www.nato.int/en/news-and-events/events/transcripts/2025/01/16/joint-press-conference?selectedLocale=.
30. Hanna Arhirova and Samya Kullab, “Ukraine Drops Its Conscription Age to 25 to Replenish Huge Troop Shortfall,” PBS Newshour, 3 April 2024, https://www.pbs.org/newshour/world/ukraine-drops-its-conscription-age-to-25-to-replenish-huge-troop-shortfall.
31. Andrew S. Bowen, “Ukrainian Military Performance and Outlook,” CRS In Focus IF12150 (Congressional Research Service, updated 2 March 2026), https://www.congress.gov/crs-product/IF12150.
32. Jahara Matisek et al., “Ukraine’s Other Allies,” Foreign Affairs, 19 July 2023, https://www.foreignaffairs.com/ukraine/kyiv-ukraines-other-allies; Jahara Matisek et al., “More than a Hobby: Informal Security Assistance to Ukraine,” War on the Rocks, accessed January 2026, https://warontherocks.com/2023/04/more-than-a-hobby-informal-security-assistance-to-ukraine/.
33. For an analysis of these systemic challenges, see Serhii Filimonov, “The Flaws in Ukraine’s New Brigades and Foreign Training Programs,” Kyiv Independent, 17 January 2025, https://kyivindependent.com/here-are-the-flaws-in-ukraines-new-brigades-and-foreign-training-programs/; Yurri Clavilier and Michael Gjerstad, “Combat Losses and Manpower Challenges Underscore the Importance of ‘Mass’ in Ukraine,” Military Balance (blog), International Institute for Strategic Studies, 10 February 2025, https://www.iiss.org/online-analysis/military-balance/2025/02/combat-losses-and-manpower-challenges-underscore-the-importance-of-mass-in-ukraine/; Andrzej Wilk and Piotr Żochowski, “Army at a Crossroads: The Mobilisation and Organisational Crisis of the Defence Forces of Ukraine,” Centre for Eastern Studies (OSW), 14 March 2025, https://www.osw.waw.pl/en/publikacje/osw-commentary/2025-03-14/army-a-crossroads-mobilisation-and-organisational-crisis.
34. AR 500-5, Army Mobilization (US GPO, 2015), 2, https://armypubs.army.mil/ProductMaps/PubForm/Details.aspx?PUB_ID=49627.
35. “DEFENDER: A Legacy of Strength and Commitment,” US Army Europe and Africa, accessed 28 April 2026, https://www.europeafrica.army.mil/Defender/. The acronym DEFENDER stands for Dynamic Employment of Forces to Europe for Deterrence and Enhanced Readiness.
36. While these technologies mitigate traditional logistics friction, they could also shift dependencies rather than eliminate them. The transition from fossil-fuel-based systems to electrified autonomous fleets may reduce the “bulk fuel” burden while simultaneously creating new strategic vulnerabilities related to rare earth element supply chains and the specialized maintenance of advanced battery systems.

 

 

 

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July-August 2026