When Russia invaded Ukraine in February, the Kremlin inadvertently put its military forces in an unsustainable position, ordering them to take on more operations than they could bear. It had nearly all its soldiers surge simultaneously and rapidly into Ukraine to fight along multiple fronts. It did so without taking necessary protective measures, such as clearing routes of explosives. It had its forces advance at an unsustainable pace. As a result, Russian troops were vulnerable to ambushes, counterattacks, and severe logistical problems that cost the military enormous numbers of soldiers and equipment.  

That initial error was caused by the Kremlin’s prewar delusions. Moscow was overconfident in its intelligence, in the ability of its agents to influence events and politics inside Ukraine, and in its own armed forces. It underestimated Ukraine’s capabilities and will to fight. And it failed to account for a massive expansion of Western support to Kyiv.

But although Russia has had six months to learn from these mistakes, it appears poised to once again commit its depleted forces to an untenable mission: annexing and holding Ukraine’s Donetsk, Kherson, Luhansk, and Zaporizhzhia Provinces, or oblasts. Holding this territory will require substantial amounts of manpower and armored equipment—particularly given that the regions have contested frontlines and that Russian forces in each experience organized partisan attacks. And Moscow has lost its most advanced equipment, for which it does not have equivalent replacements. The Russian armed forces have also suffered tens of thousands of casualties, including well-trained personnel, and its current strategy for replenishment—recruiting new soldiers from a motley mix of communities and armed groups—will not create a combat effective force. There remains, in short, a mismatch between the Kremlin’s goals for Ukraine and the forces it has to deliver them.  

The Kremlin may continue with its plans anyway, concluding that by annexing these four regions, it can force a rapid end to this phase of the war, stymie Western support for Ukraine, and buy itself time to repair and regenerate its military. If Moscow cannot marshal enough resources to support this goal, however, an exhausted Russian military will struggle to hold a contested frontline of about 620 miles. Even if the Kremlin pulls all levers available, declaring a general mobilization to call up sufficient armored equipment and trained personnel, that process would still take time. Russian forces, then, are likely to face very significant resource constraints in the next year or two. This may provide Ukrainian forces with an opportunity to push back against Russia’s efforts to hold all four oblasts.

RUNNING ON EMPTY

Russia’s invasion of Ukraine began with high-profile losses. As Russian troops advanced toward Kyiv and Kharkiv, they were vulnerable to intense fires and ambush tactics from a committed and increasingly well-supplied Ukrainian military. After the Russian offensive stalled and suffered heavy casualties, Moscow abandoned its plan to capture these cities. Instead, it concentrated its attacks on the Donbas—made up of Ukraine’s eastern Donetsk and Luhansk oblasts—and southern Ukraine, both places where the Russian military has had more success. Today, Russian forces have conquered the entirety of Luhansk, the vast majority of Kherson, and over half of Donetsk and Zaporizhzhia.

Seizing Kyiv was critical to one of Moscow’s key objectives at the outset of the war: fast regime change. When that failed, Russia downsized its plans, and now, the Kremlin’s revised intermediate goal has come into sharper focus. Through a series of policy announcements, leadership statements, and targeted military operations over the last three months, it appears that Russia seeks to illegally annex the provinces it has entirely or mostly occupied, potentially as early as this fall.

Russia has laid the administrative groundwork for such a move. It has installed Russian citizens or officials to administer occupied Ukrainian territories, appointed instructors to teach a distorted pro-Russian curriculum in schools, changed Ukrainian Internet service providers and telephone area codes to Russian ones, and confiscated Ukrainian passports to force Ukrainian citizens to acquire Russian documents. The recently installed puppet governments of occupied regions have announced so-called election commissions that could hold sham referendums on joining Russia. Moscow has created temporary security services offices in Kherson and Zaporizhzhia, nominally to help administer these southern regions but probably to break up partisan networks that could interfere with the annexation process.  

For the Kremlin, annexation would be a means to a bigger end. Should Moscow declare these territories part of Russia, it could then proclaim a cease-fire and paint continuing Ukrainian counteroffensives as attacks on what it defines as Russia. Kremlin officials might also declare that their country’s nuclear guarantees apply to all of what they consider to be the Russian Federation, as Russian President Vladimir Putin did after annexing Crimea in 2014. Such a plan assumes that the threats would deter the United States and Europe from supporting Ukraine, prompting them to curtail or even cut off arms flows to Kyiv over fears of escalation. Over time, the Kremlin hopes, Western interest in and support for Ukraine will fade, allowing Russia to set the terms of the conflict’s settlement. 

Ukraine is highly unlikely to accept any annexation or cease-fire. Ukrainian President Volodymyr Zelensky has declared that “freezing the conflict with the Russian Federation means a pause that gives the Russian Federation a break for rest.” Kyiv will almost certainly also continue to ask for Western assistance. Ukrainian and Russian goals through the end of 2022 are therefore on a collision course: one side is working to prevent the conflict from ossifying along a frozen line of contact while the other works to attain precisely that outcome.  

MUDDLING THROUGH

The Ukrainian and Russian militaries are entering a critical period in the weeks and months ahead, although for different reasons. In some areas, Ukrainian forces are outgunned, outranged, and in critical need of ammunition and certain weapons—thanks in part to Russia’s efforts to disable Ukraine’s defense industry. But in the near term, Ukraine may have a more sustainable position. The country has sufficient personnel, Western support, and a strong will to fight. Russia, meanwhile, has experienced troop and material losses that will be difficult to overcome. According to Western estimates, Russia has suffered between 45,000 and 75,000 wounded and killed personnel, from junior enlisted soldiers to generals. It has lost more than 5,000 pieces of equipment. Russia’s military has learned and adapted at the operational and tactical levels from its early defeats, shifting to new tactics that favor its superior firepower. But such battlefield adjustments are not enough to overcome the early and severe losses.

These deficits will make it hard for Russia to successfully hold the regions it may try to annex. At a minimum, if the Kremlin annexes them this fall, it will be doing so at a time of great vulnerability. To succeed, Moscow will have to replenish personnel and equipment at scale—tasks that will prove extremely difficult.

Consider, for instance, Russia’s shortage of soldiers. So far, Russia is taking an ad hoc approach to replenishing personnel, drawing from at least nine populations: active-duty troops stationed outside Ukraine, reservists, mercenary groups, Kadyrovtsy (fighters loyal to Chechen leader Ramzan Kadyrov), military prison battalions, foreign fighters, the National Guard, direct volunteers, and far-right neo-Nazi groups such as Rusich. This system is far from ideal. The Russian military and mercenary groups may be touting decent combat pay—over $3,000 a month—but they are offering short-term contracts, dropping recruitment standards, and providing only a few weeks of basic training.

Russia could drum up more soldiers by reaching into the border troops or further into the National Guard. But the country’s ability to generate personnel will also probably reach its zenith in the coming months unless it declares a general mobilization and drafts men from across the country. Even in a best-case scenario, however, mobilization would take at least several months to a year to confer an operational benefit. Russia’s mobilization base, made of equipment in long-term storage and reservists with military experience, has been largely dormant for over a decade. Expanding the system nationwide, including by calling up military-age males with no experience, would strain it significantly; thousands of officers and noncommissioned officers needed to command mobilized units are currently fighting or have already been killed in Ukraine.

Russia’s equipment problem is just as difficult to solve. According to U.S. officials, the Russian military has committed 80 percent of its active-duty army, airborne, and marine units and their equipment to Ukraine, and it has already withdrawn additional equipment from long-term storage. Although Russia has thousands more armored vehicles and missiles in storage, they are less capable and more unreliable: gear in long-term storage, for example, is mostly old and in various degrees of serviceability, often kept for years in open fields. Russia’s defense industry still has manufacturing capacity, but with its already bottlenecked and inefficient production lines under heavy Western sanctions, Russia will struggle to mass-produce new equipment on short notice. The Kremlin has taken initial steps to shore up this sector so it can better regenerate lost gear and expand its supply of missiles, but it will take many months to several years before these measures begin to show results.

THE BATTLE AHEAD

Moscow’s troubles, however, don’t guarantee Ukraine’s success. Kyiv has also lost many troops and weapons. In the near term, Ukraine, like Russia, will probably struggle to carry out new large-scale offensives or counteroffensives. Both states could be focused on ad hoc efforts to stave off exhaustion. Ukraine will need to fight hard to deny Russia a meaningful hold on the areas it plans to annex or to contest annexation if it occurs. Kyiv will also need continued Western support to implement its qualitative advantages on the battlefield. It will need to use the momentum of its counterattacks to prevent Moscow from integrating occupied oblasts into Russia.

Kyiv has said its counteroffensive in Kherson is a priority, and it is striking Russian bases at greater distances—possibly including a naval aviation base in Crimea. Russian forces in Kherson were the most vulnerable at the start of the summer, but in recent weeks, Russia has redeployed assets there from the Donbas. Ukraine can complicate Russia’s ability to fortify and annex this vital territory by using a method that worked in the opening phases of the war: inflicting battlefield losses so stark that Russia’s military leadership becomes convinced their forces cannot hold the oblast and that their positions are, or will imminently become, unsustainable. To do that, the Ukrainian military must maintain a contested frontline, attack Russian command-and-control systems, and steadily thin out Russian forces to the point that they are combat ineffective in a particular area.

Russian military planners closely study whether their forces are combat effective, including by looking at attrition rates (also known as “critical loss” in Russian military science). For Russian ground forces, military planners projected before the war that a unit becomes ineffective when it loses 50 to 60 percent of its original strength. They estimate that a regional command-and-control network is permanently broken when 40 percent of its equipment is destroyed. They believe that an air force squadron can no longer operate when it loses 70 percent of its aircraft. If Ukraine can create a highly contested frontline—just as it did outside Kyiv and Kharkiv—with attacks on command-and-control points, high rates of equipment losses, and large Russian casualties, it may again convince Moscow to withdraw. 

But for such a Ukrainian strategy to have the best chance of success, it must be in progress before Russia attempts to annex the territory it holds; that way, Ukrainian attacks can deny Russia a foothold in an area like Kherson. And even if Russia does annex Ukrainian territory and tries to force an operational pause, Kyiv and its Western supporters don’t have to comply. Russia’s overall ambitions for Ukraine, after all, remain intact. Moscow wants to annex large parts of Ukraine, it wants to demilitarize the country so that the government cannot fight against its actions, and it wants a pro-Russian leader in Kyiv. The sad reality is that annexing four regions is unlikely to be the end of Russia’s mission in Ukraine, but just one phase in Putin’s much longer project. Both Ukraine and its backers must be prepared for a protracted war.