Mykhailo SamusArticle by Mykhailo Samus, Director, The New Geopolitics Research Network
The recent infiltration of several hundred Russian infantry through Ukrainian defenses in the Dobropillia sector exposed the weaknesses of Ukraine’s current command-and-control model based on temporary structures such as Operational-Tactical Groupings (OTUs). At the same time, it underscored the advantages of a corps-based architecture. The 1st Corps of the National Guard “Azov,” which entered the line precisely in the area of the Russian breakthrough, was not a mere “fire brigade” response. Rather, it became a locomotive of combat employment under a new model of command and control – one grounded in army corps.
The transition of Ukraine’s Defense Forces to a corps system of command is neither a bureaucratic experiment nor a cosmetic reform. It is a fundamental step without which a modern army, capable of countering the Russian military machine, cannot be built. Russia itself, after the failure of its small autonomous battalion tactical group concept in 2022, reverted by 2023 to a rigid army–division vertical. Ukraine, conversely, requires a corps-based structure to establish a coherent command architecture that ensures speed, flexibility, and systematic control of all forces and assets across designated sectors of the front.
Until now, Ukraine has operated under a structure that no longer matched the scale and intensity of full-scale war. Temporary OTUs – conceived as adaptive, task-oriented headquarters – proved inadequate in practice. They struggled to manage hundreds upon hundreds of subordinate elements, lacked permanence, and failed to instill clear responsibility. Burdened with bureaucratic inefficiencies, they could not deliver resilience or accountability. By contrast, in a corps system, the corps commander assumes full-spectrum responsibility: for the sector of the front, depth of defense, logistics, training of personnel, and, most importantly, operational outcomes. This represents a qualitatively different level of responsibility that reshapes the very logic of warfighting.
American doctrine provides a clear reference point. According to FM 3-94 “Theater Army, Corps, and Division Operations”, an army corps is doctrinally capable of controlling a frontage of up to 100 kilometers and a depth of up to 200 kilometers. These metrics reflect U.S. corps – structures comprising brigades and divisions. The Ukrainian corps model, by contrast, is based on brigades. Nonetheless, regardless of the building blocks, the corps is the only echelon capable of integrating all combat and support components, ensuring coordination between organic and attached formations, conducting both offensive and defensive operations at the operational level, and synchronizing with aviation and special operations forces. For Ukraine, with a front stretching more than 1,200 kilometers, corps provide the only way to impose order on command-and-control and to allocate responsibility in line with the highest standards.
At first glance, this might seem like a technical restructuring. In reality, it is about Ukraine’s ability to win the war. Ukraine cannot defeat Russia in a symmetrical contest of numbers – tank versus tank, infantry versus infantry. Pursuing quantitative parity is a path to defeat. Survival and victory lie in asymmetry: in intellect, technology, and superior command and control. These factors compensate for Russia’s mass and can dismantle its offensive potential.
On the modern battlefield, victory does not belong to the side with more troops or machines but to the side with a faster and more precise decision-making cycle. The cycle of “detect – decide – destroy,” or what doctrine terms the kill chain, is the decisive factor. Whoever can accelerate this cycle gains the advantage, irrespective of force ratios. This is precisely how Ukraine gained early leverage with Turkish Bayraktar drones in 2022, integrating them into a network-centric approach. Today, the same applies with hundreds of thousands of FPV drones and robotic systems. Yet even the most advanced systems do not guarantee success by themselves. They are tools—nothing more. Without a command system capable of integrating them into a coherent whole, ensuring coordination, sustainment, and synchronized employment, they remain fragmented capabilities.
The corps is the level that provides this integration. It unites reconnaissance, artillery, drones, engineering, and logistics into a closed kill chain where corps-level ISR can immediately feed targeting data to artillery and drone units, decisions are made locally, and fires are delivered without delay. This integration is the key to success in both defense and offense.
Logistics is no less critical. Under high-intensity operations, sustainment becomes decisive. Brigades cannot be expected to carry this burden on their own. Corps, with their dedicated sustainment brigades, bases, and depots, assume responsibility for supply, equipment repair, and medical support. This allows brigades to focus on combat missions rather than survival in logistical chaos. Offloading brigades from excessive bureaucratic sustainment tasks also opens the way for modern models of decentralized procurement – where units directly procure what they need through innovative platforms such as DOT-Chain Defence, a digital marketplace designed to streamline procurement and delivery of weapons systems without bureaucratic delays.
Comparative Perspective: United States, Germany, Poland
In the United States, the corps is the central echelon of command in land warfare. It commands multiple divisions, integrates artillery, aviation, engineers, and logistics, and serves as the connective tissue between tactical and strategic levels. As outlined in FM 3-94, corps are responsible for large operational areas. Corps headquarters proved essential in Iraq and Afghanistan, where they enabled rapid synchronization of combat and support forces across sprawling theaters.
In Germany, after the Cold War, corps structures were largely dissolved into multinational NATO commands. The Bundeswehr emphasized divisions, while corps-level command functions were delegated upward into alliance frameworks. Yet German experience has shown that in complex operations transcending divisional boundaries, the corps echelon is indispensable for unifying planning and sustainment. In the face of renewed threats from the East, Berlin has revived its focus on the corps level.
In Poland, directly facing the Russian threat, the corps system has been embedded within NATO through the Multinational Corps Northeast in Szczecin. This is not simply a Polish headquarters but a multinational command staffed by officers from across the Alliance. It serves as a model of how corps can bridge national and allied defense structures. Moreover, Poland is building a new national corps within its land forces, modeled on the U.S. V Corps, to absorb and apply American operational experience.
For Ukraine, these cases are highly instructive. The American model shows that corps are the indispensable unit for large-scale operations. The German case illustrates the risks of abandoning corps and the necessity of restoring them in light of new threats. The Polish example demonstrates that corps can also be multinational, offering Ukraine a pathway to deeper NATO integration.
Conclusion
Ukraine cannot confront Russia through numerical parity. Its advantage lies in faster command cycles, efficient kill chains, and the ability to integrate advanced technologies into a unified command structure. The corps provides precisely this. It establishes clear responsibility, integrates all components of combat power, ensures sustainment and training, and creates the conditions for rapid and effective decision-making.
Without corps, Ukraine’s army will remain fragmented—caught between temporary headquarters and chaotic management processes. With corps, it has a chance to transform into a modern force capable not only of holding the line but of prevailing in a war where the future is decided not by mass, but by speed and precision.