This slogan is among the Army’s favorites, yet its application at the operational level remains uneven. Brigade combat teams rotate through combat training centers, maneuvering largely in isolation while simulated adjacent formations execute scripted roles that fails to introduce the friction that defines the real world’s battlefields. To compensate for the absence of field training at echelons above the brigade level, the Army increasingly relies on command post and simulation-based exercises. While such exercises are valuable for refining staff processes, they cannot replicate the uncertainty, degraded communications, and cumulative friction inherent in multidivision operations. The result is a training system optimized for confirmation rather than correction.
The Army’s shift toward preparing for large-scale combat operations has necessitated that the combat training centers reorient from training brigades on counterinsurgency doctrine to implementing the Army’s new operational concept, multidomain operations. Doctrine manuals make it clear that divisions and corps are the central maneuver elements under the new concept. To better align with its operational doctrine, the Army developed the Army of 2030 plan to reorganize the force, shifting responsibility away from brigade commanders by allocating additional resources to division and corps commanders, effectively centralizing an increasing number of resources and assets within higher echelons to limit brigade commanders’ span of control.
And yet despite these organizational structure changes and redirection of resources to divisions and above, the Army continues to rely on brigade-sized training exercises to validate its formations rather than prepare them for large-scale combat. If the service seeks to field the most capable force before its next conflict, it must invest in a key aspect of innovation: experimentation. Controlled environments and simulations are not the right venue for testing doctrinal concepts and force structures. Instead, the Army must look to two prominent examples of how to use large military exercises for experimentation and discovery: the Louisiana Maneuvers and Exercise Sage Brush. Both historical case studies demonstrate the utility of executing periodic, extensive field exercises in overcoming the expertise gap that permeates the force during periods of peace. Through these exercises, the Army can use training as a discovery tool to test concepts for fighting sustained ground campaigns in various theaters. Doing so does not require grand infrastructure project or organizational changes. It need not even involve a frequent training requirement. Rather, the Army should treat such exercises as periodic, deliberately resourced events focused on experimentation—designed to test doctrine, challenge assumptions, and expose limitations at scale before they are encountered in war.
Why Simulations Are Not Enough
For decades, the US Army has relied on command post exercises and simulations to help train staffs at echelon from the battalion to the theater Army. Augmenting field training with a virtual environment enabled the Army’s subordinate commands to train their staffs efficiently—minimizing costs while maximizing procedural and repetitive training for inexperienced staff officers. Relying on these virtual environments to train formations for large-scale military exercises made sense after the end of the Cold War. While simulations replaced resource-intensive field exercises during the 1990s, they served another purpose during the post-9/11 wars: supplementing the inability to deploy a large formation for training. The problem with relying on virtual environments to train for large-scale combat is twofold: (1) The simulation is only as useful as the assumptions upon which it is built, and (2) it fails to replicate the friction of combat.
Current simulations are built on the assumption that the Army has a tried-and-tested doctrine that can enable it to fight and win a major conflict. Recent conflicts, particularly Ukraine, challenge assumptions about maneuver, fires, and the role of unmanned systems. In response to changes in the character of warfare, the Army implemented the Army Transformation Initiative, implicitly acknowledging that its previous assumptions about warfare were wrong, yet it has failed to test operational concepts at scale. Simulations built on helping units implement multidomain operations rest on the fundamental assumption that the concept will work and is optimized for the real-world battlefield challenges units will face, an assumption that is unproven and potentially wrong given innovations diffusing from modern conflicts. Remedying this problem requires ground forces to experiment with doctrine and concepts in an environment that most closely replicates reality, one that the Army will not find in a simulated exercise.
Simulations also rely on a highly abstracted world to simplify a complex operational environment filled with friction, making the tool less than useful for experimenting with untested doctrine. Carl von Clausewitz recognized that successfully navigating friction requires experience, preferably gained through combat but realistic training can help fill the void. Few Army leaders have commanded large-scale ground combat operations, and none have done so against a peer adversary. As such, simulations are the wrong venue for effectively training and testing Army doctrine at scale across multiple echelons. Simulated exercises oversimplify and abstract tactical units’ actions, thereby removing potential sources of friction. Command post exercises mitigate or reduce the impact of issues related to span of control, misinformation, logistics, maintenance, and conceptual validity. For example, simulations fail to account for personnel shortages in low-density jobs that can lengthen maintenance timelines, to integrate the impact of terrain on vehicle performance, or to consider the quality of unit maintenance. Only through realistic, large-scale field training can the Army effectively prepare its forces and leaders to navigate the complexity of modern combat.
The Louisiana Maneuvers—Discovery Before War
Before technology-enabled simulations could supplement lived experience, the Army relied on large-scale exercises to experiment and serve as a tool for discovery for inexperienced leaders. In the fall of 1941, as the Wehrmacht utilized doctrinal innovation to sweep over Polish, French, and initially Soviet forces, the US Army brought its forces together across Arkansas, Louisiana, and the Carolinas to test its leaders and prepare them for modern combat. The gathering in the vast maneuver areas included approximately four hundred thousand soldiers, and the centerpiece exercises became known as the Louisiana Maneuvers. The scale itself was part of the experiment. General George C. Marshall, the chief of staff of the Army, sought to accomplish three main objectives: experimentation and experiential learning, strategic messaging, and leader assessment. Each exercise objective and the resulting changes reinforce the value of using field exercises, rather than simulations, as a method of discovery in the face of uncertainty.
First, Marshall wanted to replicate a realistic training environment—with no set outcomes—to experiment with doctrinal concepts and experience the complexity of modern maneuver. In planning the exercise, the Army sought to avoid a scripted, validation-only exercise. Instead, the Louisiana Maneuvers prioritized realism and provided commanders with the opportunity to exercise initiative as they saw fit. As a precursor to modern combat training centers, the Army relied on umpires to adjudicate actions and assess casualties. Despite some abstraction, the Army’s emphasis on realism enabled experimentation with doctrinal concepts and handling the friction involved in coordinating large formations. The event enabled the Army to experience the logistical challenges associated with maneuvering armies, develop procedures for air-to-ground integration, practice paratroop operations, and experiment with tank doctrine. In prioritizing the maneuvers, the Army was able to experiment with novel technologies and techniques, generating the evidence needed to overcome bureaucratic resistance to innovation. Through a willingness to experiment, the Army set the conditions to abandon outdated doctrine and invest in new capabilities—such as mechanized reconnaissance and independent tank units—that would play a critical role in the war to come.
Second, the Army, and General Marshall in particular, sought to convey the urgency of reform and equipment procurement to Congress and the American people. Contrary to the maneuvers conducted the year prior, in May 1940, the Army chose to host the 1941 version across a vast geographic area and with a much larger force package. Doing so enabled Marshall to garner widespread public attention and provide evidence to Congress and the American public of the matériel and doctrinal deficiencies within the US Army.
Lastly, Marshall sought to evaluate the Army’s senior officers to determine those best suited to lead its forces into the coming conflict. Recognizing that the Army would need to expand when war came, Marshall used the exercises to find leaders capable of leading corps and armies. He wanted to identify potential and remove those unfit for command. Marshall used the exercise to evaluate the effectiveness of senior leaders, a characteristic often lacking in modern training. The exercises surfaced future wartime leaders, including Generals Dwight Eisenhower and George Patton.
Sage Brush and the Pentomic Division—Discovery as Conceptual Attrition
Following the advent of nuclear weapons and in line with President Eisenhower’s New Look policy, the Army revised its doctrine and force structure. The resulting reorganization came to be known as the Pentomic Division. Much like current discussions of the modern battlefield, Pentomic-era doctrine prized dispersion, flexibility, and mobility. Unlike the modern Army, in 1955 the service partnered with the Air Force for a large-scale training event, Exercise Sage Brush, to test nuclear warfighting concepts. The policy of massive retaliation in place at the time forced the Army to reconcile its force structure and doctrine, leading to the assembly of eighty-five thousand soldiers at Camp Polk, Louisiana. Though the lessons from Sage Brush were more limited to the organizational challenges posed by limited nuclear use, the exercise once again serves as a useful case study for testing concepts, challenging assumptions, and preparing for an uncertain future.
In many respects, Exercise Sage Brush was a failure, but it failed usefully. One of the main lessons derived from it was that the tactical use of nuclear weapons often escalates into strategic exchanges. The Army and Air Force also failed to walk away from Sage Brush with a clear way forward to fight on a nuclear battlefield. Both services used the experience as a means of discovery, experimenting with how to fight in an environment impossible to replicate. Army leaders identified key lessons to align doctrine with the Eisenhower administration’s policy. Sage Brush revealed that nuclear dispersion demanded mobility and decentralization, but at the cost of cohesion and battlefield exploitation.
Exercise Sage Brush did not kill the Pentomic Division concept, but it provided evidence to show that it was not viable. Subsequent Army leaders would criticize the shortcomings in the doctrine that Sage Brush helped lay bare. The utility of the exercise lay not in delivering a refined and validated product, but rather in the process of experimentation that exposed the assumptions underlying the development of the Pentomic concept and the New Look policy.
Looking Forward: Revisiting the Utility of Mass Exercises
With the benefit of hindsight and case studies, we can now see that the decision to scale back large-scale exercises, driven in part by the mounting costs associated with REFORGER, and transition toward a simpler, more integrated virtual solution was a mistake. No manner of realism in a virtual environment can account for the sheer complexity of combat operations. Within the Army’s virtual simulations rests an assumption that the creator of that simulation knows how the adversary will fight and understands the future character of warfare. Breaking this cycle of confirmation bias will require the Army to return divisions, corps, and theater armies to the field.
Detractors will rightly point out many challenges to doing so. First, they will say that large-scale exercises are too expensive. The objection is understandable—but misplaced. The recently proposed $1.5 trillion defense budget undermines this argument. Add this to claims that the Department of Defense is struggling to determine how to spend the additional money, and the claim becomes less valid. In a defense budget measured in the trillions, cost reflects priority rather than possibility. If the Army is willing to redirect substantial money to the weapons and technologies it believes will enable it to win tomorrow’s wars, then it should be willing to spend enough to test those beliefs.
Additional criticisms would likely focus on the difficulty of resourcing the exercise, given limitations in manpower, operational tempo, and infrastructure. Each of these factors would pose challenges for planners, and that would be one of the exercise’s objectives. Much like the Louisiana Maneuvers highlighted deficiencies in infrastructure and logistics, this exercise would also expose shortcomings in American defense infrastructure. At the same time, the Army must determine how it can respond immediately to a crisis with the forces it has available. If deterrence is to be maintained, the military must credibly demonstrate its ability to deploy sufficient force to achieve its objectives, regardless of time or place.
Reconstituting division- and corps-level field exercises enables the Army to experiment with new doctrine, equipment, and force structures that help it respond to a rapidly changing strategic environment. Modern conflicts are reshaping the character of war. The Army must test its doctrine against those realities. Future training exercises should be used as an opportunity to discover how the Army should fight, not to simply validate that units can implement unproven concepts. Though discovery is the main tool, these intermittent corps-level events—along with other tools—help evaluate the potential of wartime commanders. Additionally, the Army should conduct corps-level maneuvers across multiple existing installations or outside typical training areas to stress test systems, hold leaders accountable, and build the necessary support among Army leaders and policymakers to drive doctrinal and institutional reform.
Unlike combat training center rotations, the purpose of periodic division and corps training events would not be to certify unit readiness. Instead, conducted every three to five years and tied to major doctrinal revisions or force design changes, they would serve as a mechanism to test assumptions about how the Army fights in different theaters and with new operational concepts.
While the scale of such exercises presents real challenges, the Army is not without viable options. No single installation in the United States can routinely support corps-level maneuver, but such training need not occur within a single contiguous area, unless the experimentation objectives require it. Instead, exercises could be distributed across multiple installations and linked through operational movement and mission command, reflecting how forces would deploy and fight in theaters such as the Indo-Pacific. In other cases, the Army could temporarily expand training into adjacent federally and state-managed areas, similar to the historical case studies and exercises such as Robin Sage. Coordinating access to land for such exercises will be challenging, but eliminating bureaucratic barriers and streamlining land management processes makes large maneuver areas available for training. The development of permanent infrastructure would not be necessary as the exercises would be periodic and intended to replicate potential operational environments. Assessing the validity of these approaches indicates that the primary constraint is not geography alone, but prioritization, coordination, and advanced planning.
Reimplementing large-scale exercises will prove challenging, especially when considering how comfortable the Army has become with using simulations as a substitute. If division and corps headquarters will be responsible for implementing multidomain operations on a future battlefield, then simulations should not suffice. The Army still expects brigades to rotate through the combat training centers, but it imposes no such requirement on its higher headquarters, despite the inherent complexity of large-scale combat operations. Periodic, deliberately resourced events tied to doctrinal and force design change can provide the Army with the means to test its assumptions before they are tested in war. An Army that only validates its concepts risks discovering its flaws in combat.
Matthew Revels is an Army strategist who serves as the Modern War Institute’s plans officer and as a senior instructor at the United States Military Academy. He currently teaches courses on military innovation and forecasting and gaming in decision-making.
Eric Uribe is a major in the US Army and a foreign area officer with an area concentration in Europe. He holds a master of arts in security studies from Georgetown University’s Walsh School of Foreign Service with a concentration in international security.
The views expressed are those of the authors and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.
Image credit: Sgt. James Dunn, US Army
