Foreign Affairs
Ukraine’s War of Endurance
The Fight for Advantage in the Conflict’s Fifth Year
Michael Kofman
February 16, 2026
Ukrainian soldiers near Chasiv Yar in the Donetsk region, Ukraine, January 2026
Oleg Petrasiuk / Ukrainian Armed Forces / Reuters
MICHAEL KOFMAN is a Senior Fellow at the Carnegie Endowment for International Peace.
On February 24, the full-scale Russian invasion of Ukraine will reach a grim milestone, grinding into its fifth year. For Ukraine, this war is a continuation of Russia’s 2014 invasion. For Russia, what was branded as a “special military operation” has now gone on longer than even the Soviet Union’s “Great Patriotic War” from 1941 to 1945 and has cost hundreds of thousands of lives. The 2022 invasion started as a failed Russian attempt to quickly subjugate Ukraine but has become Europe’s largest conventional conflict since World War II. A war initially defined by maneuver, in which Russian forces tried to leverage speed and surprise, turned into one of prepared defenses, advances measured in meters, and lengthy sieges. Since 2023, it has taken on a positional and attritional character. Now, it is increasingly a war of adaptation, endurance, and exhaustion, as both sides struggle to break out of the prevailing battlefield dynamic.
Ukraine’s goal is to make the war futile for Russia by minimizing territorial losses, pushing Russian casualties higher than the numbers Moscow can recruit, and increasing the economic costs such that the war is unsustainable. With advances in its long-range strike capabilities and a scaled-up strike campaign against Russia’s energy export infrastructure, Ukraine seeks to make 2026 the year when Russian finances reach a breaking point and Moscow must substantially revise its demands at the negotiating table. Moscow hopes that sustained offensive pressure will eventually result in breakthroughs or that its bombardment strategy against Ukraine’s critical infrastructure will make it difficult to sustain the Ukrainian economy and force people to flee Ukrainian cities. Yet Russian offensives have consistently fallen short of their aims and although Moscow hoped it could exhaust Western political will, Western support for Ukraine has proved enduring.
Ukraine performed well in 2025; it even ended the year arguably better than it did 2024, when Russian forces were advancing at an accelerated rate. The situation today is far from dire, although Kyiv entered 2026 in a difficult position. Cities are rationing electricity, and the military continues to suffer from manpower shortages. Russia’s offensive pace slowed briefly over the winter, but as of late January, it was picking up. Kyiv spent much of the past year realigning its relations with Washington and establishing mechanisms to sustain Western support. Ukraine’s drone advantage has diminished. Still, its position is not desperate. Russia cannot achieve its political goals by military means alone—it takes Moscow considerable time to capture even small pieces of territory, and doing so comes at a steep cost. The fighting is also about attaining negotiating leverage. Russia retains battlefield advantages, but they have not proved decisive, and more and more, time is working against Moscow. Yet ending the conflict on terms acceptable to Ukraine will not be an easy feat, either. It will require targeted Western support to provide Ukraine advantages in intelligence and technology, continued adaptation by Ukraine’s military to neutralize Russian advantages, and much greater economic pressure by Western countries on Moscow.
THE EARLY YEARS
Perceptions and expectations change throughout a war. In February 2022, Ukraine seemed to be on the precipice of disaster. U.S. intelligence made clear that an unprecedented Russian military buildup on Ukraine’s borders was the first stage of an operation to seize most of the country and install a pro-Russian regime in Kyiv. Yet Ukraine’s government remained skeptical that a large-scale invasion would take place until the final days; key U.S. allies, too, had a different interpretation of the intelligence. Much more could have been done to prepare and organize the country’s defense. But Washington assumed that Russia would succeed in the initial conventional phase but struggle to occupy the country. The Russian plan was heavily premised on faulty assumptions: the belief that Russia’s forces could quickly isolate Ukraine’s forces, encircle Kyiv, and shock the Ukrainian leadership with several days of strikes. Russian intelligence believed it had set the conditions for a short military campaign. Fortunately, none of these assumptions proved true. The Russian military ran headlong into resistance and was unprepared for a major conventional war and the casualties it would entail, while Ukraine rallied Western countries to its cause.
Russian forces were defeated in Kyiv and in Ukraine’s south, but they redeployed and began leveraging their remaining firepower advantage. As Ukraine’s ranks swelled with volunteers, Western intelligence and advanced capabilities increasingly helped the Ukrainian army exhaust the Russian offensive effort by the summer of 2022. Ukraine launched two successful offensives, in Kherson and in Kharkiv, with the latter leading to a major Russian rout. Yet these gains set outsize expectations for a speedy Ukrainian victory. Moscow soon launched a partial mobilization, sending hundreds of thousands of troops to the front, and began making major investments in expanding defense industrial production—essentially committing to a long war. The costly battle for Bakhmut, in the Donetsk region, from August 2022 to May 2023 signaled that the fighting ahead would be difficult.
Ukraine’s focus on Bakhmut, and the casualties it took there, ultimately cast a shadow over its plans for a decisive summer offensive in 2023. The West hoped for such a breakthrough, making few preparations for a prolonged conventional war after the offensive. But at this point, Russian forces were dug in, with a well-established reserve, and there was no element of surprise to the attack. Ukraine’s summer offensive failed. Recriminations between Washington and Kyiv followed. Afterward, Russia sought to retake the initiative, but like Ukraine, it could not overcome a prepared defense backed by mass precision—the increasingly prevalent sensors and strike drones that made it difficult for traditional mechanized assaults to achieve a breakthrough. The battlefield had changed. Drones largely prevented forces from concentrating or maneuvering near the frontline.
Ukraine’s goal is to make the war futile for Russia.
Going into 2024, Russian forces increasingly switched to assaults by small groups of infantry, while Ukraine compensated for its lack of manpower and artillery ammunition by investing more and more into expanding its drone units. The conflict, previously defined by artillery and mechanized formations, evolved into one of precision strike capabilities, electronic warfare, and drones. Ukraine’s will to fight and battlefield innovation proved critical to holding back Russian forces. Western support has also been essential, although Western capabilities have often trickled into the war rather than being deployed at scale and have been poorly timed with the needs of Ukrainian operations, reducing their impact. There has been a host of missed opportunities over the course of the war.
By late 2024, drones and drone units were not just a way for Ukraine to compensate for its deficits, but central to how its forces were fighting across a broad front. The Russian military, too, came to adopt these approaches, often copying Ukrainian innovations and at times doing a better job of scaling solutions on the battlefield. Yet despite the touted promise of a drone-based “revolution in warfare,” both Russia and Ukraine continue to deal with the typical problems of war: manpower, munitions, force generation, command and control, and defense industrial mobilization. Prepared defenses, mines, and artillery remain important factors on the battlefield. Defenses force attackers into narrow assault corridors, mines require breaching vehicles to clear and make it difficult for mechanized formations to advance, and artillery suppresses the attacking units or forces them to disperse. Drones inflict many of the losses, but the fighting is routinized and relatively static because of the numerous defensive works and minefields in place. For all the ways technology has shaped this war, the challenges both forces face are deeply familiar to those who have studied wars of the past. For a brief moment, Ukraine’s 2024 Kursk offensive seemed to restore maneuver to the battlefield, but it failed to change the prevailing dynamic and turned into an extended defensive battle.
Whereas the initial period of the war featured speed and maneuver, the current prolonged conventional war is defined more by cycles of adaptation, attrition, and reconstitution. From a distance it may not seem like much has changed in the last two years, but because of technological innovation and new tactics the battlefield changes and evolves every three to four months. Ukraine has leveraged Western intelligence, materiel, capital, and technology to help offset Russian advantages. Moscow has mobilized its resources, including a large reserve of equipment inherited from the Soviet Union. And it would not still be in the war without the support provided by China, North Korea, and to a lesser extent Iran.
THE FIGHT TODAY
The current battlefield dynamic is one of porous lines. Ukrainian forces’ forward positions are pickets with large gaps in between, and Russian forces try to infiltrate past them. This makes it hard to tell who controls what, and the contact line is more like a gray area of overlapping engagement zones, roughly ten to 12 miles from the frontline, that both sides refer to as the “kill zone.” The name is apt; given the high concentration of strike and reconnaissance drones, mechanized attacks are easily defeated and the small number of infantry that try to infiltrate through the zone are hunted relentlessly by drone units. Amid the relative deadlock, 2025 saw a brutal tug of war for superiority in the kill zone. The year began with the zone squarely positioned over Russian forces, which gave Ukraine a considerable advantage. Over time, Russia’s elite drone formations such as Rubicon, expanded drone units, and sheer numbers enabled it to move the zone more evenly across the battlefield, reducing Ukraine’s advantage. This year will see a replay of that contest, because superiority in drone capabilities is now dictating initiative on the ground.
The locus of the fighting has shifted from forward positions to the drone units and artillery providing fire support. Ukrainian units increasingly report higher casualties among support and logistical positions than among combat infantry. Ukraine has therefore used uncrewed ground vehicles more and more, to minimize losses in logistical roles and casualty evacuation. The expanding kill zone has also made it difficult to concentrate forces. Behind it, both sides employ precision strike capabilities and one-way attack drones against high-value targets. Roads are covered with counterdrone nets, every vehicle has electronic warfare systems mounted on its roof, and armored fighting vehicles look like giant hedgehogs strewn with nets and branches to add protection against first-person-view drones.
Yet the way Russia has been fighting, using small groups of infantry or lightly motorized troops to bypass Ukrainian positions, simply doesn’t generate enough momentum to turn a breach into a breakthrough. As a result, the Russian military has not been able to exploit cases in which it enjoyed localized superiority in drone units. The Russian offensive has become nearly a year-round slog, difficult to exhaust but also unsuited to achieving rapid advances. Since 2024, Russian forces have been grinding their way through the front, conducting small-scale operations across a 750-mile frontline. Although Russia’s priority remains capturing the rest of Donetsk, at any given time it has multiple axes of advance intended to pressure Ukrainian forces. This approach, however, disperses the Russian effort, enabling Ukrainian forces to hold Russia to incremental gains.
After a Russian airstrike in Kramatorsk in the Donetsk region, Ukraine, February 2026
Iryna Rybakova / Ukrainian Armed Forces / Reuters
In a war defined by attritional and positional fighting, territory changing hands is often a lagging indicator and only one way to evaluate combat efficiency. Analysts disagree about how to assess territorial control because much of the frontline is a gray zone. According to one measure by Finland’s Black Bird Group, for example, Russian forces advanced 1,930 square miles in 2025, including their counterattacks in Kursk, compared with 1,620 square miles in 2024. This includes roughly 1,780 square miles of Ukrainian territory seized in 2025 versus 1,350 square miles in 2024. These advances represent a very small percentage of Ukraine’s territory, however, and given the incremental nature of the gains, Russian forces would still have a long struggle ahead of them just to capture the rest of Donetsk. This is undoubtedly why Putin wants Ukraine to cede the region in negotiations, to avoid the lengthy fight.
With the exception of pushing Ukrainian units out of Kursk, 2025 for Russia was a year marred by operational failure. The Russian military claimed successes it had not actually achieved, and most of its advances were not along the axes it had prioritized for offensive operations. Yet although Ukraine has held on to the remnants of Donetsk, it has done so at the expense of Russian gains elsewhere in the Dnipro and Zaporizhzhia regions. Donetsk is easier for Ukraine to defend, but those regions have economic and industrial importance. In 2026, as Russian forces continue to try to push into Donetsk, the concern for Ukraine is that focusing its defense there could allow Russian forces to make accelerated gains in other regions where Ukrainian units are weaker.
A TALE OF TWO STRIKE CAMPAIGNS
Both sides have expanded their strike campaigns against critical infrastructure and defense industrial production. Russian strikes against Ukrainian infrastructure and cities, already a regular occurrence, have been particularly brutal in this year’s much colder winter. Ukraine’s hobbled electric grid is under growing pressure from regular Russian strikes on substations. Rolling blackouts have been common in Ukraine since October, but the situation has now grown so dire that residents of Kyiv received electricity for only an hour and a half or two hours some days in February. Despite Western sanctions and export controls, Russia has increased production of various types of missiles considerably since the start of the war. The growth in its production of long-range one-way attack drones has been near exponential; these now form the bulk of Russian strike packages. Whereas Ukraine faced hundreds of drone strikes per month in 2024, by 2025 it faced thousands, in combination with cruise and ballistic missiles. The latter are particularly draining on advanced Western air defenses. Ukraine has sought to address this problem with innovative approaches, scaling up its use of cheap interceptor drones and tactical radars to compensate for its shortage of air defense. But some of these solutions don’t work very well in poor weather, which is prevalent during the winter.
Ukraine’s strikes against Russian energy infrastructure have also proved effective in disrupting refined fuel supplies and in suppressing Russia’s ability to generate revenue from energy exports. Ukraine has ramped up its own drone production, and even though most drones are intercepted, growing numbers get through—Russia’s short- and medium-range air defense, tasked with intercepting drones, is increasingly strained as it races through ammunition. With the right technology transfers from Western countries, such as guidance systems and rocket motors, Ukraine could significantly expand its production of ground-based cruise missiles, too. By 2025, Ukrainian strikes were starting to make a visible impact on Russian refining and energy export infrastructure.
Ukraine’s strikes are largely oriented toward sapping Russia’s ability to sustain the war financially over the medium term. Russia faces economic stagnation, a growing deficit, regional budget crises, low oil prices, and declining oil revenues because it has needed to offer steep discounts to sell oil at all. There is growing pressure on the shadow fleet, the network of vessels Russia uses to evade sanctions and continue exporting its oil. Russia is not about to run out of money, but the economic foundations of its war effort look increasingly shaky. Regional administrators must wince as they are told their annual quotas for military recruits, given the budgetary pressures they already confront. Even Russia’s military production, the main source of industrial output over the past few years, has been leveling off. It’s unclear how long Moscow can continue spending 40 percent of the government budget, the equivalent of close to eight percent of GDP, on its military and the war.
THE CHALLENGES AHEAD
Both Russia and Ukraine face challenges in 2026. Despite Russia’s tactical adaptations, its combat efficiency is not improving. The Russian military, essentially, is preserving equipment but suffering much larger losses of manpower. From 2022 to 2024, it was able to take increasingly high casualties and still expand the force. Recruitment was strong enough that 30 percent of the new personnel could be used to build new formations. The Russian military grew from close to 900,000 before the invasion in 2022 to about 1.3 million in 2025. But almost all of Russia’s recruitment in 2025—30,000 to 35,000 enlistees per month—was to replace combat losses. By December, unrecoverable casualties (those killed and seriously injured) began to exceed monthly recruitment, which also dipped. The upshot is that the Russian military can’t expand at the current pace of offensive operations. Individual Russian units will increasingly suffer from lower manning rates and internal imbalances as it becomes more difficult to replace combat losses.
Although Russia still enjoys a considerable manpower advantage over Ukraine, the negative trends are only likely to get worse. Many Russians who were willing to take money to fight in the war have already done so, and Moscow must now try other means of gathering recruits. It has begun using reservists to guard infrastructure, for example, to free up more manpower for the front. The quality of the personnel recruited is also declining, which has contributed to climbing rates of desertion in 2025. All of this does not mean that Moscow is running out of men. Past predictions that Russia would exhaust its supply of manpower, ammunition, and equipment have proved wrong. Yet if current casualty rates hold, Moscow might have to reduce offensive intensity or the number of axes it tries to push in 2026. Without significant changes in how Russian forces fight or Ukrainian defensive mismanagement, Moscow’s hopes of achieving breakthroughs will dim.
More and more, time is working against Moscow.
Ukraine is going into the war’s fifth year with a few modest offensive successes—it has not spent all its time defending. Some units have developed an effective, systematic approach that uses drones to isolate an area and steadily degrade Russian forces there, allowing infantry to steadily take the area back. A good example of this approach was the slow-paced counterattack at Kupiansk, in the Kharkiv region, in the fall of 2025, in which Ukrainian forces eventually retook territory and cleared most of the city. Although it happened on a secondary front, that operation showed how Ukrainian units can use tactical innovations, rather than adding assault regiments to plug gaps or launching costly counterattacks, to retake terrain. The Ukrainian armed forces have consistently used technology, too, to offset their manpower disadvantage.
The challenge for Ukraine is maintaining the force’s combat strength at the front. Drone units often expand by recruiting within the military rather than outside it. Despite advances in autonomy and artificial intelligence, most systems in Ukraine remain crew-operated and require maintenance, logistics, and enabling technologies. In brief, drone warfare is still manpower-intensive. Unfortunately, this is where Ukraine faces problems. Thousands of personnel are absent without leave. Soldiers are tired, and in the tougher sectors, those in the infantry spend many months in their positions without rotation. And as the fighting shifts from combat infantry to drone units and specialists, losses become increasingly difficult to replace because people serving in those positions require much more training to develop specialized expertise.
Although its maneuver formations are tactically innovative and well led, Ukraine has struggled with force management. New units are still being formed without sufficient officers, manpower, or equipment, and their creation comes at the expense of reinforcing existing units. With little in the way of an operational reserve, elite units are sent to firefight across the front to counter Russian advances. Newly established corps are supposed to make the fight more cohesive by coordinating the action of subordinate brigades, and in several cases they have succeeded, but commanders are still constrained by micromanagement—they cannot change their positions, for example, without approval from the higher levels of command. A policy of “not one step back,” effectively a prohibition against retreat, prevents brigades from running a mobile defense and leads to the formation of salients, with Ukrainian forces slowly being enveloped by enemy advances. Worse, some commanders simply misreport their positions as defense proves unsustainable in the face of constant Russian assaults. Ukraine will have to address these manpower and force management issues to reduce its losses and stay ahead of the Russian military in the coming year.
THE WAR IN 2026
In 2025, the war took on an increasingly regional character. Russia and Ukraine expanded their attacks against commercial shipping in the Black Sea. Ukraine has also targeted Russia’s shadow fleet in other waters, while Moscow has been brazenly violating NATO members’ airspace and conducting drone flights over their infrastructure. These campaigns are only likely to expand as relative deadlock prevails on the battlefield. But there is always a possibility that gradual transitions will become sudden ones. Forecasting in war often relies too much on extrapolation from prior phases. Yet seemingly small changes can have ripple effects. Ukraine, for instance, has recently blocked Russia’s use of Starlink, which will significantly affect its ability to operate uncrewed ground vehicles and certain types of strike drones—or, most important, force a reorganization of Russian command and control at the tactical level.
In 2026, Ukraine will need to stabilize the frontline, find scalable and affordable solutions to Russian strikes against infrastructure, and use drones and domestically produced cruise missiles to inflict greater economic damage on Russia. Much of this has already been in progress for the past year. But a bigger shift in momentum will depend on whether Ukraine can transition from simply inflicting higher levels of attrition on Russia at the front to controlling the battlespace at greater depth and reclaiming the superiority it once enjoyed in drones. At present, Russian forces enjoy an advantage in strike capabilities beyond 20 miles or so; Ukraine often faces a shortage of cheap and effective means to engage Russian forces at that distance. This asymmetry must be redressed if Ukrainian operations are to achieve effects beyond attrition.
Last year, Russian President Vladimir Putin made two bets. The first was that sustained pressure and attrition would cause a collapse of Ukrainian lines. The second was that Russian diplomacy would turn the United States against Ukraine, eliminating critical American support for the war effort. Washington did stop providing military support as aid, but it set up an arrangement in which Europeans now pay for continued U.S. support for Ukraine’s war effort. Essentially, both of Putin’s bets proved wrong. How the fighting proceeds from here will inform negotiations, and the key question will be which is more sustainable, Russia’s offense or Ukraine’s defense. Last year’s battles suggest that going into the fifth year of the war, Moscow’s military prospects have not significantly improved, while economic strain mounts.
Wars are contests of will and endurance as much as they are contests of systems. Washington is visibly impatient, seeking a settlement by the summer, but an artificial timetable cannot easily be imposed on this conflict. This is not, and was never, simply about land. Moscow aims to impose its will on Ukraine and destroy it as an independent state with a distinct national identity. Ukraine suffers from exhaustion, but not desperation. Although Ukraine faces challenges, time is less and less on Russia’s side, however much Moscow portrays the situation otherwise. Moscow cannot wish away the fundamental mismatch between the military means it has available and the political aims it seeks to achieve.
Topics & Regions: Russia Ukraine Geopolitics Security Defense & Military Strategy & Conflict War & Military Strategy War in Ukraine
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