Contents:1. Corps system: what systemic improvement entails2. Effective kill chain: what modern corps can achieve3. Types of corps: USA, Germany, Poland4. How to implement foreign experience in Ukrainian realitiesThe infiltration of several hundred Russian infantry through Ukrainian defenses along the Dobropillia axis clearly highlighted the shortcomings of the old command system and, at the same time, emphasized the advantages of a corps-based architecture. The First National Guard Corps, Azov, which entered the responsibility zone at the site of the Russian breakthrough, was not merely a “firefighting team.” In practice, it became the locomotive for operational application of the new command model based on army corps.Corps system: what systemic improvement entailsThe transition of Ukraine’s Defense Forces to a corps command system is not a bureaucratic experiment or cosmetic reform. It is a fundamental step without which it is impossible to build a modern army capable of resisting Russia’s war machine. Since 2023, after the 2022 failure of small autonomous battalion tactical group concepts, Ukraine returned to a hierarchical army-division structure. Naturally, one must respond to the enemy, who learns from their failures and improves. The goal is to create a clear command architecture within the Defense Forces that ensures speed, flexibility, and systematic control over all forces and resources in a designated front sector.Until now, Ukraine operated under a structure that could no longer meet the scale and intensity of combat on the Russian-Ukrainian front. Temporary operational-tactical groupings, created “for the mission” (theoretically a modern model of flexible and adaptive operational command), proved ineffective when managing hundreds of control points. Their temporary nature led to a lack of responsibility and efficiency and got bogged down in bureaucracy. This approach provided neither stable command nor accountability for results. In the corps system, however, the corps commander is responsible for everything: the front sector, defense depth, logistics, personnel training, and most importantly, operational outcomes. This represents a qualitatively higher level of responsibility, changing the very logic of warfare.Effective kill chain: what modern corps can achieveAmerican doctrine provides a clear benchmark. FM 3-94, Theater Army, Corps, and Division Operations, specifies that an army corps can effectively manage a front sector up to 100 km wide and 200 km deep. While these standards apply to American-type army corps with brigades and divisions, a Ukrainian corps is brigade-based. Regardless, a corps can integrate all combat and support elements, ensure coordination between organic and attached units, conduct offensive and defensive operations at the operational level, and synchronize actions with aviation and special operations forces.Creating corps allows Ukraine, with a front exceeding 1,200 km, to organize command, assign responsibility zones, and meet the highest operational standards. While this seems like a structural change, it is fundamentally about Ukraine’s ability to win the war. Ukraine cannot defeat Russia in symmetric combat—tanks versus tanks, infantry versus infantry. Relying on numbers alone leads to defeat. Survival and victory require asymmetry: intelligence, technology, and refined command. These factors offset enemy numerical superiority and degrade its offensive potential.On the modern battlefield, victory goes to those with faster, more precise command cycles. The “find-target—decide—engage” cycle, or kill chain, has become decisive. Rapid detection, decision-making, and engagement confer an advantage regardless of force ratios. Ukraine applied this in 2022 with Turkish Bayraktars integrated into a network-centric approach. Today, the same principle applies with hundreds of thousands of FPV drones and robotic systems. However, even the most advanced systems alone do not guarantee victory; they are tools. Without a command system that integrates them into a cohesive whole, ensures coordination, and manages logistics, they remain isolated capabilities.A corps builds such a system, combining intelligence, artillery, drones, engineering, and logistics into a closed kill chain. Corps intelligence instantly provides data to drone or artillery units. Decisions are made locally, and fire is applied without delay. This integration is key to success in both defense and offense. Logistics is equally critical. High-intensity combat demands robust logistics. Brigades alone cannot bear this burden. A corps, with its own rear structures, bases, and depots, manages supply, equipment repair, and medical support, allowing brigades to focus on their missions instead of survival amid supply chaos. This logistical “unloading” enables modern models like DOT-Chain Defence, a digital platform functioning as a marketplace to order and deliver weapons swiftly, bypassing bureaucratic delays.Types of corps: USA, Germany, PolandIn the U.S., a corps is the central land force command, managing multiple divisions and integrating artillery, aviation, engineering, and logistics into a unified operational structure. Corps HQs ensured operational success in Iraq and Afghanistan by rapidly synchronizing combat and support forces.In Germany, post-Cold War corps were largely integrated into NATO structures. Divisions remained, while corps-level functions shifted to multinational command. The Bundeswehr experience shows that in complex operations exceeding a single division, corps-level planning is crucial. Germany is now reviving focus on this level amid rising threats from the east.In Poland, facing a direct Russian threat, the corps system was integrated into NATO through the multinational “Northeast Corps” in Szczecin. This is not merely a national command but a multinational body with officers from multiple NATO countries. Poland is also establishing a corps in its Land Forces modeled after the U.S. Fifth Corps to maximize adoption of American experience.Implementing foreign experience in UkraineFor Ukraine, these examples are particularly valuable. The U.S. shows the corps as a foundational unit for large-scale operations; Germany highlights the risks of abandoning corps structures and the need to restore them under new threats; Poland demonstrates that corps can be national and multinational, opening prospects for Ukraine’s NATO integration.Ukraine cannot confront Russia by relying on numerical parity. Success depends on faster command cycles, an effective kill chain, and integrating advanced technologies into a unified command system. The corps provides this foundation: defining responsibility, integrating forces, ensuring logistics and training, and enabling rapid decision-making.Without a corps system, Ukraine’s army remains fragmented between temporary structures and chaotic management. With corps, it gains a chance to become a modern force capable not only of withstanding but of winning a war where speed and precision, not mass, determine the outcome.This material was prepared in collaboration with the Consortium of Defense Information (CDI), a project uniting Ukrainian analytical and research organizations to strengthen information support and analytical capacity in national security, defense, and geopolitics.