History is an imperfect guide, but it suggests wars that endure for more than a year are likely to go on for at least several more and are exceedingly difficult to end. A Western theory of success must therefore prevent a situation in which the war drags on, but where Western countries are unable to provide Ukraine with a decisive advantage.


As the Russian winter offensive reaches its culmination, Ukraine is poised to seize the initiative. In the coming weeks, it plans to conduct an offensive operation, or series of offensives, that may prove decisive in this phase of the conflict. This is not Ukraine’s only remaining opportunity to liberate a substantial amount of territory and inflict a major defeat on Russian forces, but the upcoming offensive may be the moment when available Western military equipment, training, and ammunition best intersect with the forces set aside by Ukraine for this operation. Ukraine is also eager to demonstrate that, despite months of brutal fighting, its military is not exhausted and remains able to break through Russian lines.

Policymakers, however, have placed undue emphasis on the upcoming offensive without providing sufficient consideration of what will come afterward and whether Ukraine is well positioned for the next phase. It is critical that Ukraine’s Western partners develop a long-term theory of victory for Ukraine, since even in the best-case scenario, this upcoming offensive is unlikely to end the conflict. Indeed, what follows this operation could be another period of indeterminate fighting and attrition, but with reduced ammunition deliveries to Ukraine. This is already a long war, and it is likely to become protracted. History is an imperfect guide, but it suggests wars that endure for more than a year are likely to go on for at least several more and are exceedingly difficult to end. A Western theory of success must therefore prevent a situation in which the war drags on, but where Western countries are unable to provide Ukraine with a decisive advantage.

Ukraine may well achieve battlefield success, but it will take time to translate military victories into political outcomes. The West must also prepare for the prospect that this offensive may not achieve the kinds of gains seen during Ukraine’s successful operations in Kharkiv and Kherson. By placing too many bets on the outcome of this offensive, Western countries have not effectively signaled their commitment to a prolonged effort. If this operation proves to be the high point of Western assistance to Kyiv, then Moscow could assume that time is still on its side and that bedraggled Russian forces can eventually wear down the Ukrainian military. Whether Ukraine’s next operation is successful or not, Russia’s leader may have few incentives to negotiate. For Ukraine to sustain momentum—and pressure—Western states must make a set of commitments and plans for what follows this operation, rather than maintain a wait-and-see approach. Otherwise, the West risks creating a situation whereby Russian forces are able to recover, stabilize their lines, and try to retake the initiative.


After successive defeats in Kharkiv and Kherson, the Russian military was vulnerable heading into the winter. But the Ukrainian armed forces also sustained losses and expended ammunition in those operations, which forced them to focus on their own reconstitution. Despite earlier optimism that Ukraine could press its advantage into the winter, the Ukrainian military was not in a strong position to sustain its offensive and achieve further battlefield gains. Mobilization and the successful withdrawal from the right bank of Kherson helped Russia stabilize its lines, build a reserve, and develop a more sustainable rotation for units off the frontline. The Russian military also began building more sophisticated defenses across the frontline in Ukraine with minefields, antitank obstacles, and trenches. By shortening the front and upping the number of personnel deployed, the Russian military also increased the force density relative to the terrain it was defending. What followed was a period of grinding attrition where neither side had a significant advantage.

Fortunately for Ukraine, Russia’s political leadership proved impatient, abandoning a defensive strategy and replacing the more competent General Sergey Surovikin with Valery Gerasimov, the Russian chief of the general staff, as the commander of its forces in Ukraine. Gerasimov launched an ill-conceived and ill-timed offensive across the Donbas starting in late January. The Russian military, still recovering, was in no position to conduct offensive operations given its deficits in force quality, equipment, and ammunition. Moscow had mobilized more than 300,000 personnel, which it quickly used to replenish the Russian forces, but it could not restore sufficient offensive potential. Quantity matters, but a military cannot rebuild its quality in just a few months.

In practice, then, Russia’s winter offensive was dependent on a small percentage of its military, primarily naval infantry and airborne units, which had taken heavy losses throughout the war and were increasingly relying on mobilized personnel as replacements. At Bakhmut, most of the fighting was done by the state-affiliated Wagner paramilitary organization instead of the regular armed forces, which largely played a supporting role. In general, the Russian military demonstrated that it was no longer capable of large-scale combat operations. Instead, it conducted localized attacks with smaller formations and assault detachments.

The Russian military nonetheless attempted to attack along six axes—Avdiivka, Bakhmut, Bilohorivka, Kreminna-Lyman, Marinka, and Vuhledar—hoping to strain Ukrainian armed forces across a broad front. But compared with the battle of the Donbas in 2022, Russia had a weaker advantage in artillery during these campaigns, and this deficiency further limited its offensive potential. Russian forces did regain the initiative through these assaults and fixed Ukrainian forces in place, but despite thousands of casualties, the Russian military gained little territory and the offensive did not result in a significant breakthrough. Instead, Russia’s offensive further weakened its military by expending manpower, materiel, and ammunition. These losses will give Ukraine its best opportunity to launch a counteroffensive. Russia’s attempts to seize the Donbas this year also illustrated that Moscow’s strategy continues to suffer from a mismatch between political aims and military means.


Yet in the battle for Bakhmut, over time, Ukraine’s position became precarious. The Ukrainian armed forces have been partially enveloped since February, and they no longer enjoy as favorable an attrition ratio as they once did. Bakhmut is surrounded by high ground, which gave Russian forces an advantage once they seized the southern and northern flanks in January and February, respectively. The situation looked dire in early March. Although Ukraine stabilized the flanks by committing additional forces, allowing it to secure the remaining main supply route into the city, Russian forces have now captured most of the city. Moscow did not have the forces required to encircle Bakhmut, which could have led to a significant victory, so it instead focused on the more symbolic win of taking the city itself.

Compared with the battle of Vuhledar and other parts of the front during Russia’s winter offensive, Ukraine’s attrition ratio in Bakhmut is less favorable, and a smaller share of Russia’s casualties are from elite units. Elements from Russia’s 106th Guards Airborne Division and other Russian military units are operating along the Bakhmut front, but Wagner is leading the fight, particularly in the city itself. The majority of Russian casualties sustained in Bakhmut are from Wagner, and the majority of Wagner’s losses have been from minimally trained convicts. Those losses matter, but losing convicts affects Russia’s overall war effort much less than losing regular soldiers or mobilized personnel, especially outside settings like Bakhmut. Wagner convicts represent a minimal investment and are not individuals taken out of the economy, and so their losses lack political ramifications. Given Wagner’s heavy reliance on convicts, it is not clear that that approach would have proven effective outside an urban setting like Bakhmut.

During Ukraine’s previous offensives, the backstop for the Russian military was its airborne and naval infantry, not Wagner forces. For Russia, then, it may turn out that the heavy losses sustained among elite units in Vuhledar, such as the 40th Naval Infantry Brigade and 155th Naval Infantry Brigade, were more strategically important than the relative losses in Bakhmut. The losses in Vuhledar could make it difficult for Russian forces to defend against Ukraine’s upcoming offensive. But Ukraine may also find that the forces and ammunition it expended to defend Bakhmut, in relatively unfavorable terrain, will impose a constraint on operations later this year. Furthermore, Wagner’s assaults fixed a significant number of Ukrainian forces over the winter, giving the Russian military time to stabilize its lines and entrench.

Bakhmut is significant mostly for political and symbolic reasons. Strategically, it is a gateway to Slovyansk and Kramatorsk, but Ukraine continues to hold better defensive terrain west of the city. Capturing it does little to help Russian forces further advance, and they may be hard pressed to defend it afterward. But in the end, military strategy is political, as it bridges military operations with political objectives. Ukraine’s leadership is keen to avoid giving Russia any kind of victory which might bolster Russian morale, and it has chosen to continue defending Bakhmut.

It is therefore too early to judge the effect of the battle for Bakhmut on this war. The result will be clearer in hindsight. Ukrainian forces avoided encirclement and managed to inflict high costs on the Russian military, even if most of the losses appear to be among Wagner units. Long term, the significance of the resources both sides expended in the battle will likely be the most important factor. Whether Ukraine could have pursued a better approach in this instance will be a subject for historians to debate.


Ukraine has sought to build a force capable of conducting an offensive on top of its currently deployed formations. Kyiv has assembled three corps composed of mechanized (or motorized) infantry brigades. These new units include roughly nine maneuver brigades armed largely with Western-provided equipment and at least three generated by Ukraine. These brigades will likely consist of newly mobilized personnel, perhaps with a core of experienced soldiers. The units will be backed by several assault brigades, as part of the Ukrainian Ministry of Interior effort to stand up an “Offensive Guard” force in support. But as the offensive draws near, it is not clear what percentage of these units will be completed for the operation, or if the supporting brigades will be assembled in time.

The challenge Ukraine faces is that, despite an influx of Western equipment, its force is largely mobilized, uneven in quality, and training on a compressed schedule. And over the course of the past year, the Ukrainian military has taken significant casualties. Many junior officers, noncommissioned officers, veteran soldiers, and troops previously trained by NATO have been lost in the fighting. This is a very short amount of time for newly mobilized soldiers to master new equipment and conduct combined-arms training as a unit. In general, Ukraine’s advantage has been that as a force it has proven more adaptable, much better motivated, and more rewarding of initiative than the Russian military.

Ukraine has fought the war its own way, with a mixture of mission command at junior levels and at times Soviet-style centralized command at the top. It has placed a strong emphasis on artillery and attrition over maneuver in warfare, while also integrating Western precision and intelligence for long-range strikes. The Western approach has been to train Ukrainian forces in combined-arms maneuver in an effort to have them fight more like a NATO military would, similar to what the West has taught in past train-and-assist programs. The challenge with this approach is that NATO militaries are unaccustomed to fighting without air superiority, especially air superiority established and maintained by American airpower, or at least with the logistics and enabling capabilities that the United States typically brings to the fight. As a result, Ukrainian soldiers must tackle Russia’s prepared defenses without the kind of air support and logistics that their Western instructors have long been accustomed to.

It is up to the loser to decide when a war is over.

Russia’s defenses are not impenetrable, but they could be strong enough to attrit Ukrainian forces over multiple defensive lines, while buying time so reinforcements can arrive. Their defense-in-depth is designed to prevent a tactical breakthrough from achieving strategic effects—in particular, to stop a Ukrainian breakthrough from generating momentum. The upcoming offensive will therefore test the current theory of success in Kyiv and across contributing Western capitals: that Ukrainian forces, trained and equipped with Western systems, can fight more effectively and break through fortified Russian lines.

Both the new Ukrainian formations and the Russian defensive preparations will be largely untested at the start of the offensive, making the course of the coming battles difficult to predict. Similarly, it is unclear whether the West has provided sufficient enabling capabilities for Ukraine’s offensive, such as breaching equipment, mine-clearing machines, and bridging gear. Despite the commonplace focus on big-ticket items like tanks or fighter jets, it is enablers, logistics, and training that often have the largest effect over time.

Russia’s sizable, mobilized force proved to be ineffective at conducting offensive operations over the winter, but it is easier for poorly trained units to defend than to attack. It is unclear what effect attrition in elite Russian units and ammunition expenditure during Russia’s winter offensive will have on Ukraine’s upcoming offensive. Although the Russian military is preparing for Ukraine’s counteroffensive, Russia has misspent valuable resources, and Russian morale may be low—leaving its forces vulnerable. Soft factors and intangibles, which are difficult to measure, are likely in Ukraine’s favor. Nonetheless, the situation is less propitious for Ukrainian forces than it was in Kharkiv in September. Ukraine’s task is daunting. It must not only succeed but also avoid overextension.


The challenge with the upcoming offensive is that, despite being saddled with high expectations, it appears to be a one-shot affair. Ukraine is likely to receive a substantial injection of artillery ammunition ahead of this operation, but this package will offer a window of opportunity rather than a sustained advantage. Western efforts to support Ukraine suffer from short-term thinking, delivering capabilities just in time or as a surge for the offensive operation but with little clarity on what will follow.

Whether successful or not, Ukraine may witness another period of indeterminate fighting after this offensive, comparable to what followed its successes in Kharkiv and Kherson. The reason for this is twofold: Western countries made key investments in production capacity late into this war, and much of the West’s support appears to be focused on the short term—then seeing what happens next. The gap between Western efforts is filled by Russian efforts to stabilize the lines and reconstitute, along with prolonged periods of attrition. Indeed, Ukraine may be forced to fight with less artillery or air defense ammunition late this year than it was expending during the Russian winter offensive.

Yet what has remained constant is that analysts and policymakers who believe that the next weapon system sent to Ukraine would prove to be a game-changer have consistently been disappointed. Conventional wars on this scale require large numbers of equipment and munitions and scaled-up training programs. Capability matters, but there are no silver bullets. Ukraine will likely retake territory in its upcoming offensive and may significantly breach Russia’s lines. But even if Ukraine attains a military victory, or a series of victories, this does not mean that the war would end at that point. It is up to the loser to decide when a war is over, and this conflict is just as likely to continue as a war across the Russian-Ukrainian border.

At this point, there is little evidence that Russian President Vladimir Putin will willingly end the conflict, even if the Russian military is facing defeat. He may seek to continue it as a war of attrition, no matter the prospects for Russian forces on the battlefield. Putin may assume that this offensive represents the high point of Western assistance and that, over time, Russia may still exhaust the Ukrainian military, perhaps in the third or fourth year of the conflict. These assumptions may be objectively false, but as long as Moscow believes that the next offensive is a one-off affair, it may reason that time is still on Russia’s side. Similarly, if Ukraine is successful, then neither its society nor its political leadership will be keen to settle for anything other than total victory. In short, it is unlikely that the coming offensive will create good prospects for negotiations.

Among Western countries, there are competing visions for how the war might end.

That said, Russia does not seem well positioned for a forever war. Russia’s ability to repair and restore equipment from storage appears so constrained that the country is increasingly reliant on Soviet gear from the 1950s and 1960s to fill out mobilized regiments. As Ukraine acquires better Western equipment, the Russian military has increasingly come to resemble an early Cold War–period museum. There are also growing signs of strain on the Russian economy, where energy sale revenues are becoming constrained by sanctions and Europe’s pivot away from Russian gas. Even if Moscow can keep mobilizing manpower and bringing old military equipment onto the battlefield, Russia will face growing economic pressures and shortages of skilled labor.

Russian forces in Ukraine still face a structural manpower problem, and despite a national recruitment campaign, Moscow will likely need to mobilize again to sustain the war. It is desperate to avoid doing so. If the West can sustain Ukraine’s war effort, then despite its resilience and mobilization reserves, Russia may find its disadvantage growing over time. In recent months, European countries have begun making the necessary investments in artillery production and issuing procurement contracts, although some of these decisions are coming more than a year into the war.

Some may hope that a successful offensive may soon thereafter lead to a negotiated armistice, but this must be balanced against the prospect that a cease-fire will simply yield a rearmament period, after which Moscow will likely seek to renew the war. Whether an armistice favors Russia or Ukraine is debatable. Russia will certainly seek to rearm, but the extent of continuing Western military assistance to Ukraine is uncertain. Consequently, the way this war ends could lead to a follow-on war. After all, the current conflict is a continuation of the original 2014 Russian invasion of Ukraine.

Among Western countries, there are competing visions for how the war might end. A defeat for Moscow is not the same as victory for Kyiv, and one does not have to travel widely in Europe to discover that not everyone defines a Ukrainian victory in the same way. Some see the present situation as already a strategic defeat for Moscow; for others, this outcome remains indeterminate. As it stands, what follows the coming offensive will reveal whether Western countries are arming Ukraine to help Kyiv fully restore territorial control or just to put it in a better position for negotiations.

Although the coming Ukrainian offensive will do much to set expectations for the future trajectory of this war, the real challenge is thinking through what comes after. The offensive has consumed planning, but a sober-minded approach would recognize that supporting Ukraine will be a long-term effort. It is time, then, for the West to start planning more actively for the future, beyond the coming offensive. History shows that wars are difficult to end and often go on well beyond the decisive phases of fighting, including as negotiations continue. For Ukraine and its Western backers, a working theory of victory must be premised on endurance, addressing Ukraine’s long-term force quality, capability, and sustainment needs. The United States and Europe must make the necessary investments to support the war effort well beyond 2023, develop plans for successive operations —and avoid pinning their hopes on any single offensive effort.