Two years after Russia’s invasion, Ukraine and its Western supporters are at a critical decision point and face a fundamental question: How can further Russian advances on the battlefield be stopped, and then reversed? After capturing the ruined city of Avdiivka, Russian forces are moving forward fitfully in other areas along the front. Russian advantages in manpower, materiel, and defense production have grown in the past year, whereas U.S. ammunition deliveries have been throttled and are at risk of being curtailed almost entirely because of an impasse over funding in the U.S. Congress. Supplies of critical munitions for frontline Ukrainian units are dwindling, and soldiers are being forced to ration. Some units are experiencing significant manpower shortages.

The current battlefield dynamics have no single cause; they are mostly rooted in decisions that were made since the fall of 2022. When Russia mobilized its war economy, the West did not, and Ukraine could not. When Russia constructed a network of defensive fortifications hundreds of miles long and multiple layers deep, Ukraine did not. Russia obtained more than a million (by some estimates, three million) artillery shells and thousands of drones from its partners, including Iran and North Korea. The West could not match that, having already reached the bottom of the barrel of similar resources. Moscow has gone to great lengths to regenerate personnel and replenish its forces, whereas Kyiv has yet to fully mobilize.

Without a surge in Western military aid and major changes to Kyiv’s strategy, Ukraine’s battlefield position will continue to worsen until it reaches a tipping point, possibly by this summer. On the present course, in which Ukrainian ammunition and manpower needs are not met, Ukrainian units are likely to hollow out, making Russian breakthroughs a distinct possibility. But this is no time for despair; it is time for urgent action. Russian forces have vulnerabilities that can be exploited and advantages that can be eroded over time, but only if Ukraine gets what it needs now.

DAMAGED BUT DANGEROUS

To create an effective strategy that capitalizes on Russia’s weaknesses, Western policymakers and observers need to see the Russian military for what it is now: not the hapless, broken, depleted force that many wished it would be by now but a still dangerous organization advancing in Ukraine. Understanding the current state of Russian combat power means processing contradictory information and answering a number of complex questions. Is the Russian military in decline, reliant on Soviet-era equipment, conscripted convicts, troops who abuse methamphetamines or other drugs, and foreign-supplied drones and artillery shells in order to push forward at high cost? Or is it an increasingly adaptive and well-resourced organization, able to overpower Ukrainian positions all along the frontline?

The trouble is that both descriptions are partly accurate. Perhaps the clearest and most practical view of the Russian military is an anecdote told by Ukrainian soldiers and recently shared with The New York Times: the Russian army is neither good nor bad, just long.

In the opening months of the war, the Kremlin was reluctant to admit that its initial blitz on Ukraine was a failure. By August 2022, damaged Russian units had become brittle, and when tested by Ukrainian forces they collapsed in Kharkiv and retreated from Kherson. But Russia has since come to terms with the requirements and costs of a prolonged conflict. Realizing that its war effort was in peril, the Kremlin did what it had not wanted to do previously: it mobilized 300,000 men, dramatically increased defense spending, and purchased essential weapons from its partners to bridge gaps.

Kyiv now finds itself in a sustainment crisis similar to what Moscow experienced two years ago. But unlike Russia, Kyiv cannot mobilize its defense industry and quickly scale up production; it must rely on Western military assistance. Ukraine also has a smaller population than Russia, which means its casualties are felt more deeply.

When Ukrainian forces are sufficiently manned, supplied, and entrenched, however, they have shown that they can inflict high costs on Russian forces and frustrate Russia’s ability to convert its on-paper advantages into decisive gains. The battle for Avdiivka is the most recent case in point: using frequent airstrikes and committing up to 30,000 men across a dozen units, Russia still needed five months to capture the ruined town. Russia wanted Avdiivka badly, and it got Avdiivka … badly: in the course of the siege, it lost more than 600 armored vehicles and likely thousands of soldiers. The heavy losses underscore that Russia’s offensive capabilities are still deficient when trying to overwhelm prepared Ukrainian defenses.

There are few locations left across the frontline, however, that are as heavily defended as Avdiivka was, meaning that future Russian advances may come more easily. Furthermore, Russian weaknesses will matter very little if depleted Ukrainian units can no longer mount a defense, or if they cannot rapidly replicate the types of defenses that were constructed at Avdiivka over ten years.

THE LAST RIDE OF THE SOVIET ARMY

Russia’s two main advantages are its remaining weapons and manpower, though even these are not as strong as the Kremlin would like its enemies to believe. Take Russia’s vast reserves of armor: since 2022, its forces have lost at least 14,000 pieces of equipment. The Russian general staff has offset some of these losses by exhuming the grave of the Soviet army and refurbishing for use thousands of mothballed tanks and armored vehicles. In 2023, Russia revived 1,200 tanks and 2,500 armored vehicles that were previously in long-term storage while producing only 200 new or modernized tanks. But these stockpiles are not infinite. Some researchers have noted that Russia has already removed between 25 to 40 percent of its strategic reserves depending on equipment type, and the best equipment was probably pulled early on. What remains is likely to be in worse shape or even unsalvageable. If Russia continues at this rate, its remaining inventory will dwindle in the next couple of years, and its future options will be constrained as a result. This depends, of course, on whether Ukraine is resourced to mount an active defense and regenerate its own combat power.

The West has not kept pace with Russia’s ammunition production. Although Russia draws from its older ammunition stockpiles, it has also accelerated new artillery production. It is on track to produce two million 122-millimeter and 152-millimeter artillery shells by the end of this year, and has purchased an estimated one to three million rounds of artillery from North Korea and Iran. If the United States and the European Union hit their production goals, they intend to collectively produce about 2.6 million rounds, and not all of that will go to Ukraine. In early March, the Czech Republic announced that it could broker 800,000 artillery rounds for Ukraine from third parties, but delivery timelines are closely guarded.

Ukrainian air defenders have also had to ration their interceptor missiles. Russian missile attacks have grown more experimental and complex since late 2022, and Ukraine’s interception rates have declined as a result. In early January, Ukrainian officials said that lower-altitude air-defense systems around Kyiv could withstand only a few more large attacks.

The erosion of Russia’s equipment and ammunition advantages will matter very little if Ukraine is not resourced to defend itself in 2024. It will not matter if Soviet-era tanks are less capable and survivable if Ukraine is not given the supplies to destroy them. It will not matter if foreign artillery shells have a higher “dud rate” than domestic versions, if Russian forces can maintain a firepower advantage of around five to one, and Western production and delivery delays continue. It will not matter if Russian long-range precision-strike missile production has reached its zenith—or if, as Ukrainian officials say, Western sanctions are reducing the quality of Russian missiles—if Ukraine is not equipped to defend its skies. In this worst-case scenario, Russian heavy bombers could be used to destroy Ukraine’s cities and critical infrastructure.

HUMAN RESOURCES

Russia’s initial mobilization in 2022 was chaotic, with untrained personnel rapidly deployed to plug holes in frontline units. In the months that followed, however, the Russian military set up a pipeline for regenerating units at training ranges in occupied Ukraine and Belarus. Russia is now regenerating enough manpower to keep its lines stable and launch limited offensive operations through at least the rest of the year. After fending off Ukraine’s counteroffensive last fall, it introduced more troops into occupied Ukraine. For instance, Russian and Ukrainian forces in occupied Donetsk were roughly equal in September 2023; by February, Russia had a two-to-one advantage. Ukrainian commanders noted earlier this year that some Russian forces appeared better trained than they were last year; others still use crude tactics to simply overwhelm or exhaust Ukrainian troops.

Despite Russia’s capacity to recruit more soldiers, manpower is still a constraint on the Kremlin’s ambitions. Russia cannot easily translate its greater supply of men to superiority on the battlefield without risks. Although Russian military officials claim to have 25 million personnel available, they have in practice only what they can generate through volunteer pipelines. Out of concern for domestic stability and regime security, the Kremlin prefers not to call for another round of mobilizations if it can be avoided. Even if the Kremlin wanted to occupy larger swaths of Ukraine by 2026, it is far from certain whether it would be willing to accept the risks of staffing a force large enough to accomplish this aim.

Ukraine and Russia are both having difficulty enlisting sufficient troops in their 20s and early 30s, the preferred age range for infantry. For Kyiv, it is a matter of policy; only men who are 27 and older are mobilized. Although Russia has a larger overall population, its military-recruitment challenges are compounded by labor shortages and the emigration of hundreds of thousands of men since 2022. If Russia were to expand the scope of its offensive operations through 2024 and 2025, its pipeline of volunteers would be insufficient on its own, and the country would likely need more rounds of mobilization.

Russia uses cash incentives and expensive social guarantees to attract volunteers. To meet quotas, authorities also use coercive methods such as conducting raids on factories, dormitories, and even restaurants looking for men to enlist, and pressuring immigrants and inmates. Russia is recruiting foreign fighters—and soon possibly foreign felons—into its ranks as well. Recruiting convicts may have already passed the point of diminishing returns. Before the war, the population of Russia’s prison system was stable at around 400,000 to 420,000. By 2024, that number had declined to 266,000, almost certainly as a result of recruiting by the Russian military and by private mercenary companies such as Wagner.

The remaining convicts may not be available to enlist, either, because Russia typically employs around 100,000 prisoners at any given time to help with persistent labor shortages across the country. Russian authorities estimate a shortfall of 4.8 million domestic workers. These shortages extend across multiple industries and a majority of Russian regions. Labor pools that were tapped to resolve past shortages—migrants, prisoners, students—are now needed for the war or for conscription. Unfortunately, Russia’s looming manpower challenges in 2025 and beyond will matter very little if the brute-force tactics of Russian troops exhaust and overwhelm Ukrainian units in 2024.

HOW SOON IS NOW?

For much of the past five months, Russia’s strategy was to conduct multipronged attacks to deplete and exhaust Ukrainian forces along the frontline. Then it made Avdiivka its main target. Once the city fell, in mid-February, Russia immediately intensified its attacks in that direction and elsewhere. Russian forces have very few reasons not to continue their assaults. By persisting, they maximize momentum before the ground thaws and mud returns, take advantage of understrength Ukrainian forces as they ration equipment, and engaging Ukrainian forces before they have time to fully dig in, all while American aid is stalled in the U.S. House of Representatives.

Overall, it is a bad sign for Ukraine and its supporters that Russia has enough confidence in both its own abilities and Ukraine’s precarious position that it is accelerating attacks in the run-up to the Russian presidential election, in mid-March. These offensives would likely not be authorized if the Kremlin were uncertain about its prospects for success. In other words, Russia is forecasting more battlefield wins.

Russia’s current objectives appear to be advancing to the boundaries of Donetsk and rolling back the results of Ukraine’s 2023 counteroffensive in Zaporizhzhia. In Donetsk, they may be trying to reach the city of Pokrovsk in order to secure key road and rail networks and seize the remainder of the Donetsk oblast, or province, from which they could eventually attack the remaining Ukrainian strongholds near Kramatorsk and Sloviansk. Russian forces will likely try to make headway in the Zaporizhzhia oblast as well, particularly around Orikhiv, where the terrain is open and fewer Ukrainian defensive positions have been prepared. In the north, Russian forces are trying to approach Kupiansk, which could act as a toehold in the Kharkiv region.

A full reoccupation of western Kherson seems unlikely given the difficulty of the terrain there, Russian manpower and force availability notwithstanding; furthermore, the destruction last year of the Kakhovka Dam now limits paved routes over the Dnieper River in Kherson. Nor are there signs that Russia is amassing the forces required to reoccupy the Kharkiv region by the end of 2024. For Russia to attempt a new offensive on the entire region, the rest of the frontline would need to be stable—with Ukrainian forces fixed in place or unable to redeploy—and Russia would need to generate at least another combined-arms army but probably more (50,000 to 100,000 men, depending on the status of Ukrainian defenses). These circumstances do not exist today. But if conditions on the battlefield do not change, and if Russia generates sufficient force, this could be Ukraine’s future.

To hold their positions in 2024, Ukrainian forces need urgent replenishment of ammunition and manpower. If reinforcements are coming, Ukraine can defend the frontline this year and regenerate combat strength while the West’s industrial base ramps up for 2025 and beyond. Western military assistance—specifically American aid—must be approved quickly to sustain critical ammunition supplies and to maintain existing combat systems. Next, Kyiv must generate and train personnel to replenish frontline units. Unfortunately, finding more soldiers will most likely require an unpopular mobilization. Aid delays make Kyiv’s dilemma even worse. Finally, Ukraine must accelerate the construction of prepared defensive positions.

Without these urgent steps, Ukraine’s rationing of ammunition will continue through the spring and summer. Facing continual Russian attacks, undermanned units could become increasingly hollowed out and lose the ability to defend themselves. Unless immediate changes are made, this is the path that Ukraine and the West are on.

The Russian military’s long-term weaknesses will not matter if Ukraine is not supported this year. Ukrainian frontline soldiers are in mounting jeopardy—not because they lack the will to fight or do not know their enemy’s weaknesses, but because of shortfalls in ammunition and manpower. If the West, specifically the United States, does not want to see the frontline in Ukraine continue to bend or—even worse—break, it must urgently approve aid. And if Kyiv wants to sustain its efforts, it has to make difficult choices about how to generate more manpower. Time is running out.