What’s new? The spring of 2024 finds Ukraine on the back foot as Russian troops advance in the east. After months of delay, the U.S. Congress authorised much-needed aid. But to reach a successful outcome, Kyiv and its partners must apply the past year’s difficult lessons in planning for a long war.

Why does it matter? A victory for Moscow would leave Kyiv facing political subjugation and a larger-than-pre-invasion Russian army close to NATO’s borders. The resulting costs and risks, including the prospect that the Kremlin might test its luck beyond Ukraine, would be substantial.

What should be done? The best hope for meaningful diplomacy and sustainable peace is for Kyiv to hold the line against Moscow. Ukraine should better mobilise and train front-line troops while bolstering defensive positions. Its Western partners should increase arms production and deliveries, with Europe preparing to compensate if a divided U.S. steps back.

A big reason for the reversal of Ukraine’s fortunes was Russia’s own resiliency, and corresponding capacity to bounce back from its 2022 losses, while withstanding the pressure that the West brought to bear with economic sanctions. Moscow has benefited from high energy prices and prudent financial management; the willingness of many states to skirt sanctions and trade with it nonetheless; the successful redirection of its domestic industry to serve a war economy; and a wide-ranging effort to acquire weaponry from places like Iran and North Korea.

At the same time, 2023 underscored significant weaknesses in the hand that Kyiv is playing. One is the contingent nature of the Western support upon which it is fundamentally reliant. Although Europe’s leaders seem solidly behind Ukraine’s defence (not surprisingly, given the implications for continental security), political polarisation makes the U.S. a less dependable partner, not least because former President – and current presidential candidate – Donald Trump appears to be deeply sceptical about U.S. support for Kyiv. If the U.S. cuts back its assistance, Europe will need to fill the gaps. While it is ramping up its capacity to do so, it still has quite a distance to travel. Moreover, Western leaders face tough questions about what kinds of weapons to give Ukraine, with what sorts of caveats, as they both seek to enable battlefield success while avoiding dangerous escalation with a Russia that has threatened and (according to some accounts) internally discussed the possibility of using nuclear weapons as the war continues. 

On the home front as well, Ukraine faces big challenges. Overmatched by Russia’s sheer size, it must keep mobilising more front-line troops and give them the training they need to go confidently into battle – something with which it has struggled to date. While outside supporters supply ample training, it is insufficiently calibrated to battlefield realities. A feeling that troops are unprepared for what awaits corrodes morale and contributes to prospective conscripts desperately trying to avoid service. More broadly, neither the military nor civilian authorities near the front seem to have adequately planned for the moments when they will find themselves on the back foot during a long war.

But while Ukraine does not have the wind at its back, it is far from defeated. The challenge in the coming period will be to slow Russian advances to an eventual halt and then hold the line. For their part, European states will need to accelerate work to adapt their defence industries to produce for Ukraine in the near term and for themselves in the long term. That means overcoming supply chain bottlenecks, coordinating and putting more money into defence procurement, and sorting out the challenges of collective action, such that frustration over some countries doing more and others less does not undermine the broader effort. Although one lesson of 2023 is that ramping up defence production is easier said than done, firms are off to a solid start: one German company will nearly double production in the coming years, and artillery manufacturing in Europe looks set to be a growth industry. 

All the same, getting Ukraine the advanced weaponry it seeks and, in all likelihood, needs will require its backers to walk a careful line. As in the past, the best approach will likely involve continuing to slowly scale up their assistance in kind as well as quantity, although they should improve their internal coordination of this strategy to mitigate delays from deliberation to delivery. Such gradual increases, such that the U.S. is now providing Ukraine with longer-range missiles it would not have considered sending even a few months ago, has proven an effective way to shift Russian perceptions of the threat that aid poses to Moscow. This approach will always involve risk, but experience to date indicates that there is no better way to minimise it.

Kyiv itself will need to ensure that it has the trained personnel it needs to use the weapons provided and a sustainable strategy for the long term. Its partners can help with training, but it is up to the Ukrainians to define their needs and to take stock of how to fix a system that has put perhaps a million people in uniform but struggles to get enough to the front to hold positions. Revamping training to ensure that people are not sent to the front unprepared will help. So, too, will more transparency about rotations and demobilisation as well as better outreach to soldiers’ and veterans’ families. Meanwhile, both military and civilian authorities should prepare for a frequently shifting front line and the tactical, humanitarian and political implications thereof. That means not just building defences and continuing asymmetrical strikes on Russian targets but also putting in place adaptable plans for evacuations.

If Ukraine and its backers do not move fast to fix the problems, Kyiv may have little choice but to strike a deal on Russia’s terms. While such a deal might bring an end to fighting in the near term, it will do so at tremendous cost not just to Ukraine, but also to European security, increasing the risk of additional bloodshed for years to come. If they can hold the line, however, they stand a chance of arriving at a reasonable agreement with Moscow that preserves Ukraine’s security and autonomy, while allowing European governments to begin to put in place arrangements that help make the continent more stable over the long haul.

Kyiv/London/Washington/Brussels, 28 May 2024

If the first year of full-scale war in Ukraine was one of tectonic shifts, the second revealed a more gruelling reality that has left Kyiv struggling. After Russia’s multi-front invasion in February 2022, Ukraine surprised observers with its resiliency, while Russia’s poor preparation defied expectations of a powerful Russian military machine. Russia failed in its paramount objective – to quickly remove Ukraine’s political leadership and replace them with people beholden to Moscow. In the autumn of 2022, after Kyiv recaptured substantial territory in the Kharkiv and Kherson regions that Moscow had occupied in the early days of its campaign, the rosiest scenarios had Ukrainian victory in sight.[1] 

2023 was a very different year. Hopes that Ukraine might mount a counteroffensive capable of retaking more territory, including breaking the land bridge connecting Russia through south-eastern Ukraine to Crimea, were soon dashed. Ukraine’s troops had trouble piercing Russia’s formidable defensive lines, spurring recriminations in Kyiv that echoed debates between Ukraine and its backers preceding the counteroffensive. Some among Ukraine’s supporters voiced concerns that Kyiv had begun the offensive too late; that it misallocated forces along the front line; and that it failed to strike boldly enough in the south.[2] The U.S., which at least for the present is Kyiv’s key arms supplier, struggled to overcome domestic political roadblocks that slowed crucial military aid. As 2024 dawned, it seemed that Russia’s much larger population, productive capacity and enduring trade relations might give Moscow a decisive battlefield edge. 

Washington threw Kyiv something of a lifeline in April. The U.S. House of Representatives – the lower chamber of the U.S. legislature – overcame internal divisions to approve a $61 billion aid package for Ukraine and the Biden administration rushed to move materiel out the door. It announced a first $1 billion tranche of assistance and teed up rapid deliveries of ammunition, air defence munitions and armoured vehicles – some pulled from stocks in Europe.[1] It then announced a further $6 billion package, some of which will take time to work its way through the pipeline.[2] The White House has also sent long-range Army Tactical Missile Systems to Kyiv, setting aside earlier qualms about supplying long-range weaponry.[3] Senior Western officials are looking through their inventories for Patriot long-range air defence missile systems that are at the top of Ukrainian President Volodymyr Zelenskyy’s wish list – with U.S. Defense Secretary Lloyd Austin urging allies to give up batteries they might prefer to keep for their own defence.[4] But Western moves to add to Ukraine’s arsenal run real escalatory risks that will require careful calibration. 

As May draws to a close, fighting remains fierce, and Russian troops continue to creep forward while Kyiv and its backers hope that the influx of new weapons will halt the Russian advance, if not reverse it immediately. While behind closed doors, both Ukrainian and Western officials have long accepted that success does not require that Kyiv regain all its territory by force of arms, no one presently seems to see space for negotiations that could allow at least a pause in combat. The reason is rooted in Russia’s insistence that it will negotiate only for Ukraine’s surrender and demilitarisation, as well as curtailment of Western support for Kyiv, at least for the near term. It seems confident that, eventually, Kyiv will have no choice but to accept those terms. But until it is either proven right or its confidence wanes, war will continue. 

This report seeks to draw the key lessons of the setbacks that Ukraine and its partners faced in 2023, suggesting how these can be applied to hold the line before Russia’s advance so as to make meaningful diplomacy possible. It is based on dozens of interviews with Ukrainian, Russian, European and U.S. officials, civil society figures, aid agency employees and defence experts over the past year. The report also relies on government documents and news articles from Ukraine, Russia, Europe and the U.S. from the same period, as well as past Crisis Group writing and research on Russia’s war in Ukraine.[5]

The first several months of 2023 saw Ukraine and its Western partners preparing for the launch of a major counteroffensive against Russian forces amid soaring expectations.[1] Those with high hopes appeared to include President Zelenskyy. He reportedly brushed off arguments from people within his government that to get ready for what was shaping up to be a protracted fight, Kyiv should take time to build defensive lines rather than pressing the attack at the earliest opportunity.[2] Beyond a surfeit of confidence, other reasons militated in favour of moving quickly. Kyiv may have felt it had to show major gains to maintain Western public support for the war and counter those who argued that the conflict was becoming a quagmire. Behind closed doors, U.S. politicians admit that making the case for military aid was much easier when Ukraine appeared to be winning.[3]

Even so, many of those closest to the fight anticipated trouble. As the counteroffensive began in June 2023, some Ukrainian leaders and generals tried to temper expectations, fearing that Ukraine would have difficulty making strategic gains as Russian forces were well entrenched.[4] Then-Defence Minister Oleksiy Reznikov told the Washington Post in early May that “most people are … waiting for something huge”, which he said could lead to “emotional disappointment”.[5] In Washington, senior officials also sounded a cautionary note, with Defense Secretary Austin warning that “Ukraine's fight is not some easy sprint to the finish line”.[6]

The sceptics proved correct. By all accounts, Ukraine’s losses in the first days of the counteroffensive, as tanks and troops met dense minefields guarded by watchful Russian drones and attack helicopters, sent shock waves through the top brass.[1] Ukraine switched tack, reverting to a familiar attritional strategy: it would rely more heavily on long-range firepower to disrupt Russian supply lines and destroy its logistical hubs, while probing for weaknesses along three axes of the more than 1,000km front. The fighting that followed was slow and bloody. By the end of 2023, Ukraine had gained only a few hundred square kilometres of territory. In the first months of 2024, it lost more than it had gained in the year prior.[2] 

The costs of attrition fell disproportionately on Ukraine. In Russia, the war economy enabled easier ramp-ups of weapons and soldiers (and bombs were not falling on its munitions factories). In contrast, Kyiv increasingly had difficulty getting the trained troops it needed to the front. As for resources, Kyiv had been heavily reliant on successive U.S. packages of assistance, which dried up just as the counteroffensive fizzled. While both the White House and a majority in Congress supported a $61 billion aid package put forward in the fall of 2023, a small but powerful group of allies of former President Donald Trump in the House of Representatives obstructed it for months.[3] In January, the Biden administration announced that it could make no further deliveries until it received new funding (although it did find a way to supply a $300 million package in March).[4]

Ukraine’s European backers tried to make up the difference in arms deliveries, but they struggled to execute. By March, the EU had sent less than a third of the one million artillery shells it had promised.[5] To plug the gap in Kyiv’s near-term needs, they belatedly scrambled to obtain ammunition from around the world, in an initiative developed by the Czech Republic and financed by its European allies – but those items, too, were slow to reach the front lines.[6] After highly damaging Russian barrages prompted desperate pleas from Kyiv, Germany launched the Immediate Action on Air Defence initiative, calling on European allies to find and finance more air defence systems.[7]

Ukraine did have successes in 2023, almost entirely thanks to asymmetric tactics. It downed a variety of Russian aircraft and struck targets inside Russia. Its Black Sea strikes, some with homemade drones and others with missiles supplied by the UK and France, had Russian boats avoiding the sea’s western half by late 2023.[1] By the spring of 2024, Ukraine estimated its forces had disabled or destroyed a third of Russia’s Black Sea fleet, leading to week-long spans when no Russian vessel left port.[2] This campaign also enabled Kyiv to resume grain shipments via a route hugging the Black Sea’s western shore, which had been halted when Russia pulled out of the deal that had made commercial maritime traffic possible, despite the war, until the summer of 2023. Kyiv claims that ports in Odesa and nearby were exporting almost as much grain in January 2024 as they were before the full-scale war began.[3]

But these successes did little to offset frustration with the ground counteroffensive. The rancour came to a boil in a late 2023 quarrel between Ukraine’s top military commander, Valerii Zaluzhnyy, and President Zelenskyy when the former described the war as a “stalemate” in The Economist, only to be contradicted by the latter.[4] The next February, Zelenskyy replaced Zaluzhnyy with his ground forces commander, Oleksandr Syrskyy, and Ukrainian troops began falling back to defensive positions, having been forced to give up the strategic town of Avdiivka. Although slowly and at high cost, Russia continued to seize more territory even as Ukraine dug new defensive lines. Meanwhile, until the April breakthrough with the aid package in the U.S. House of Representatives, Ukrainian generals were unsure if they would have enough ammunition to keep fighting in the months to come.[5]

Russia’s resilience over the last year has surprised its adversaries. Despite far-reaching sanctions imposed by the U.S. and its European allies, Russia’s economy and war machine have increasingly seemed invigorated rather than destroyed by the war in Ukraine. “They are still producing more weapons and they still have more friends than we had hoped”, a senior European official said.[1] 

Moscow has stayed strong in part through effective fiscal management honed over years of earlier Western sanctions, many put in place for its earlier encroachments upon Ukrainian sovereignty, but also because its trade did not evaporate as Western states thought it would.[2] Russian budget revenues were up by more than 50 per cent in the first quarter of 2024 compared to 2023, thanks to high energy prices and changes in taxation of oil companies.[3] With many countries unwilling to abide by sanctions they had no role in defining, Moscow kept exporting. China has replaced the EU as Russia's main trading partner.[4] A Western bid to cap oil prices at $60 per barrel hurt Russian sales somewhat in the first half of 2023, but Russia was soon selling at higher prices, with India and China buying up supplies.[5] Russia has also found ways to use banks and intermediaries in the Gulf Arab states, Türkiye and the Eurasian Economic Union to procure sanctioned goods.[6]

Moreover, even where sanctions worked – for example in depriving Russia’s arms industry of sophisticated components – Moscow has proven nimble, making do with less advanced weaponry and being creative about where it gets parts.[7]After the full-scale invasion began, Russia started looking for Soviet-standard arms and ammunition wherever it could, both in post-Soviet countries and farther abroad.[8] In addition, like other sanctioned goods, materials needed to build weapons are passing through China, Türkiye and Gulf Arab countries, as well as Central Asian states.[9] Russia has also pummelled Ukraine with ballistic missiles and shells from North Korea and drones bought from Iran.[10] 

Putin has put the Russian economy on a war footing, with a third of the national budget spent on defence.[11] With factories running around the clock, Russia has gone from making some 40 long-range missiles per month to about 100.[12] As for artillery munitions, a NATO intelligence estimate put Russian production capacity at 3 million a year – far surpassing Europe’s current capacity.[13]“Russia has this ability to kickstart the military-industrial complex to produce”, a senior European government official said. “I mean, they’re ahead of us now”.[14] Russia understands that its productive capacity gives it a leg up over Ukraine, where the arms industry is growing but faces frequent bombing and which would be lost without the Western aid it depends on.[15] The Ukrainians have “no weapons industry of their own, no money of their own, and so no future”, said Putin expansively (if inaccurately) at a December Kremlin ceremony. “But we do”.[16] 

Finally, there is the issue of troop strength. With a population more than four times that of Ukraine, Russia has maintained a flow of soldiers to the front despite reportedly huge casualties. According to independent calculations at the end of February, some 75,000 Russian soldiers may have been killed in two years of war in Ukraine, although the casualty rates seem to be declining.[1] In the meantime, according to official figures, Russia mobilised about 300,000 troops in 2022 and recruited about 590,000 more in 2023-2024.[2]It has kept the ranks full by increasing payments to soldiers and recruiting from the poor and prison populations. It has also pressured conscripts to sign contracts. In exchange for a variety of benefits, the contracts require young men to serve longer than the single year conscription mandates and make them eligible to be sent into combat. 

These moves seem to have helped Russia overcome the challenges of low morale, fatigue and discord within the armed forces about how to wage the war, which perhaps reached a peak in the summer of 2023, when the late Yevgeny Prigozhin led his Wagner paramilitary forces on a march to within 200km of Moscow before agreeing to turn them around.[3] Stories of soldiers serving on the front for over a year and bribing commanders to get leave have faded.[4] A movement of mothers and wives demanding that soldiers be sent home was met with repression.[5]

Looking to the future, Moscow has issued new regulations to make mobilisation easier.[6] These increase the number of men subject to compulsory military service by raising the maximum age at which it could call them up from 27 to 30.[7] It has digitalised draft notices following a spate of fires that destroyed paper documents at mobilisation facilities in 2022. It has also banned draftees from leaving the country, as hundreds of thousands did when Russia began a large mobilisation in the autumn of 2022, and imposed stiffer penalties on those refusing to serve.[8] 

As the war’s tide seemed to turn in its favour over the course of 2023, the Kremlin’s confidence increased. While many experts argued that its battlefield gains would be minimal, as Ukrainian defences were too strong, some speculated that Russia might try to mount offensives while it knows Ukraine is struggling to fill its ranks and arsenals.[1]

As of now, it seems to be doing just that. Russia’s military progress until April was mainly in Donetsk, part of eastern Ukraine’s Donbas region. Just as some analysts had forecast, and perhaps in a bid to draw Ukrainian forces away from the front in the east, in May Russia reopened an offensive to the Kharkiv region, where Ukraine had proudly recovered the vast majority of what Russia had grabbed in 2022, enabling it to mount attacks on nearby Russian border regions.[2] It is possible that, if successful in Kharkiv, Russia will press ahead there (including in Kupiansk), in Donetsk and in the neighbouring Sumy region.

Still, Russian manoeuvres thus far are small-scale and not necessarily groundwork for a larger operation, which would require far more soldiers. Should Putin attempt a major offensive, Western defence officials and Russian sources say, it could go badly, costing Russia much in blood and treasure.[1] Moscow may be hoping to wear Ukraine down before it takes the plunge: “We are expecting two very difficult months for both Russia and Ukraine, but if Ukraine doesn’t hold out, things could start moving fast”, a Kremlin adviser told Crisis Group.[2]

The stakes go beyond Moscow’s territorial control, however. Moscow’s paramount objective is political – ie, to subjugate Ukraine by demilitarising it and limiting its foreign support. Russia will continue seeking battlefield gains but simply as a means to this end.[3] “The Kremlin is waiting for Ukraine to wear itself out and make an offer to initiate negotiations”, said a Russian political strategist with close ties to the Kremlin. “There is no alternative strategy at the moment”.[4] While a Kremlin adviser told Crisis Group that “Putin is absolutely serious when it talks about negotiations to bring the war to an end”, the pose is misleading, coming as it does with the caveat that talks must begin with Ukraine accepting “new realities”.[5] By this phrase Moscow refers not just to Russian control of parts of Ukraine, but also to its claims to Ukrainian land it does not hold but purports to have annexed. More recently, Russian officials have also spoken of a “sanitary zone” reaching further into Ukrainian-controlled territory.[6]

The narrative created by this open invitation to join negotiations, however self-servingly framed, feeds the Kremlin’s efforts to cultivate the good graces of countries loath to take sides in the conflict and those looking for reasons to oppose the West. It allows Moscow to paint itself as a force for stability and Kyiv as intransigent while also lending fodder to sceptics in the West, who believe Kyiv should be strong-armed into negotiating with the threat of withdrawing support.[7]

For the most part, Kyiv’s Western backers continue to believe that a Moscow that attains these gains in Ukraine will pose a growing threat. They point to Russia’s proposals of late 2021 – made amid last-minute Western diplomatic efforts to ward off its full-scale invasion – which would have hamstrung NATO’s capacity to defend its eastern members from future attack by keeping allied forces off their territories, suggesting that Moscow’s goals have not changed.[8] Indeed, Russia’s foreign policy “concept”, issued in 2023, centres a global confrontation with the U.S., whose alliances the Kremlin aims to weaken.[9]

Thus far, Russia’s attack on Ukraine has boomeranged on that front, notably with Finland and Sweden joining NATO, but that is hardly reason for Russia’s neighbours or the alliance as a whole to be sanguine. Ukraine’s defeat and demilitarisation would leave countries outside NATO exposed. Moldova and Georgia, which have received EU candidacy status but lack security guarantees from Western states, would be exposed to tremendous Russian pressure. A Moscow further emboldened by successes, still on a war footing and with a much larger army, could even look to test NATO’s wherewithal by encroaching on an alliance member’s lands, if not in the immediate future, then in the years to come.

This new Russian approach, and indeed this new Russia, may or may not be sustainable. Russia has battled persistent inflation, and it will likely have to raise taxes on businesses and trim social welfare programs to maintain record levels of defence spending. Although it has succeeded in evading many sanctions, it has felt a weapons squeeze.[1] While it has seemingly been able to keep soldiers flowing to the front, a large-scale mobilisation, such as that needed to launch a substantial offensive, would still be difficult for Moscow. Furthermore, Russia has miscalculated in the past, including in launching the February 2022 invasion with inadequate personnel, equipment and planning. It may do so again. 

That said, Russia does not need to convince its adversaries that it can keep going forever: it only needs to persuade Ukraine and its backers that it can last longer than they can, even as Kyiv attempts to do the reverse.

Over the course of 2023, the notion that Western supporters would provide war-sustaining assistance to Kyiv indefinitely yielded to a more complicated reality, at least in Washington. In the early days following Russia’s all-out invasion, U.S. and other Western leaders, committed, in the oft-repeated words of President Joe Biden, to back Ukraine “as long as it takes”.[1] But toward the end of 2023, Biden, speaking alongside the visiting Zelenskyy, instead said the U.S. would offer support “as long as we can” – and underlined that it was impossible to keep doing so without supplemental funding.[2] This money was held up in the House, highlighting a new divide: aid for Ukraine has become a fault line separating a core group of Trump supporters from the mainstream political establishment.

Trump’s allies on the populist right disagree fundamentally with the administration’s approach both to Ukraine and the trans-Atlantic partnership that has united Western nations behind it. They have insisted that money spent supporting Kyiv should instead be allocated to what they regard as more pressing tasks, especially stemming irregular migration to the U.S. A prominent Trump surrogate in the 2024 election campaign, Senator J.D. Vance, a Republican from Ohio, also argues that the U.S. lacks the productive capacity to arm Ukraine at the same time that it meets Israel’s, Taiwan’s and its own needs.[3] More broadly, the Trump-Vance wing of the Republican Party envisages a reconfiguration of the trans-Atlantic security partnership that reduces the U.S. role and enlarges that of Europe, which these politicians contend can do much more to fend for itself.[4]

How precisely this division will play out with respect to support for Ukraine is not fully clear. Trump himself did not vocally oppose the April aid package, reportedly because Republican supporters of the bill lobbied him hard and included face-saving measures – in particular, structuring part of the package as a loan – that the former president favoured.[5] But Kyiv cannot relish the idea of a second Trump administration. Trump’s threats to withhold military aid from Ukraine unless Zelenskyy gave him political dirt on Biden was the basis for his first impeachment in 2019, and it is hard to imagine that he would be a reliable supporter were he elected in 2024.[6] Indeed, Trump has said he would take no more than 24 hours to hammer out a peace deal between Moscow and Kyiv – which Ukraine and its friends understandably presume would mean pressure on them to settle with Russia on unfavourable terms.[7] Regardless of whether he wins, Trump’s scepticism about both aiding Ukraine and trans-Atlanticism will shape the politics of these questions as long as he remains a force.

European backing, while not militarily of the same scale as U.S. aid, is arguably on firmer political ground, though as the war drags on it will likely also face challenges, especially if far-right parties pick up seats in national legislatures and the European Parliament. Over the last two years, member states have been keen for Europe to assume greater responsibility for continental security, including by ramping up arms production, though they continue to debate what that means. Talk of a more integrated defence union has surfaced, but even its proponents have trouble articulating what it would look like. Should the far right gain traction amid a protracted conflict, discussions about military, financial and humanitarian assistance to Ukraine could become more polarised within and among EU member states. 

For right now, the EU’s Ukraine supporters are doing what they can to lock in assistance for the long term. They overcame Hungary’s threatened veto on 1 February to agree upon a €50 billion, four-year aid package – the first tranche of which was released in March.[1] They have also stepped up military assistance, with combined (military plus other) European aid overtaking the U.S. total in 2023.[2] The UK, France, Italy, Denmark, Latvia, the Netherlands, Germany and Finland have signed agreements with Ukraine for continued weapons shipments and other security assistance. Similar deals with Norway and the EU as an institution are under negotiation. These pledges are meant to signal that support will remain steadfast.[3]

But Ukraine’s needs will remain substantial for as long as war lasts, and its most urgent requirements for arms and other materiel are not yet something that Europe can meet on a sustained basis. The gap between EU commitments and allocations remains large.[4] Nor is the new U.S. aid package in itself adequate to keep Ukraine going into the future: the funding should guarantee about a year’s worth of U.S. help, although some components will run out earlier and others arrive later.[5] Especially if the U.S. does not follow up with additional large-scale aid, Europe will need to shoulder more of the burden. 

The West has encountered other challenges as well in its efforts to assist Ukraine. In considering whether, when and how to ramp up aid, partner governments have been constrained by several factors above and beyond the political considerations described above. These include limited availability of the materials in question, bureaucratic hurdles and fear that certain weapons or tactics might cross Russia’s red lines.[1] Among the scenarios of greatest concern to Western powers is that NATO troops might be drawn into direct conflict with Russian forces, creating an escalatory dynamic that would be hard to contain and could even lead to nuclear use.[2] Western leaders have also worried that providing weapons that Ukraine then uses to strike deep into Russia might be seen by Moscow as tantamount to direct NATO involvement.[3]

Such fears have resulted in much deliberation and a piecemeal approach to the provision of new weapons systems to Ukraine. The slow pace brought benefits: it bought time to assess Russian responses and mitigated the escalation risks in the war’s most uncertain early months.[4] Intentionally or otherwise, it may have allowed the West to provide more advanced armaments over time: had the same items, in the same numbers, been sent sooner, Russia might have reacted more aggressively. 

But incrementalism also created anomalies and costs. Western states (often including the U.S.) repeatedly ruled out providing a weapons system only to succumb to pressure to do so months later. Repeatedly, Ukraine’s non-U.S. partners tested the waters by sending a new system first, and the more cautious U.S. later followed suit.[5] For example, President Biden long withheld Army Tactical Missile Systems (ATACMS), which have a maximum range of 300km, from Ukraine for fear of crossing Putin’s red lines and amid scepticism that these missiles were the best means of hitting Kyiv’s targets (eg, supply nodes and air bases).[6] But the White House changed its mind, transferring a small number of older missiles of the same type with a maximum range of 165km, after Ukraine had been firing British Storm Shadow and French SCALP missiles, which are similar, for months. In the spring of 2024, amid talk that the U.S. would finally decide to send longer-range ATACMs to Ukraine, reports emerged that it had already done so in secret.[7]

A related issue is the caveats that Western countries put on their long-range systems. Until recently, U.S., French and British missile shipments were all contingent on Ukraine using the projectiles to hit targets in Russian-held parts of Ukraine but not in Russia itself.[8] (Kyiv has used Ukrainian-made weaponry to strike targets in Russia.[9]) The UK is now lifting this restriction, but the U.S. and French have kept it in place.[10]

Ukraine, not surprisingly, would like as much freedom to use long-range weaponry as it can get. In 2022, Kyiv was able to leverage U.S. HIMARS rocket launchers to strike deep in Russia’s rear to disrupt supply lines. It would like to do so again, but with Russia having dispersed supply lines precisely to avoid such attacks, Kyiv would need to be able to fire on Russian territory.[1] Its strikes in Russia to date have hit high-profile targets – military sites and oil facilities – to demonstrate capacity. These operations are risky, however: Russian experts argue that Moscow’s devastating assaults on Ukrainian energy infrastructure in the spring of 2024 are at least partly a response to the latter attacks (they added that Kyiv would reject a deal to eschew energy infrastructure strikes, declining to say if Moscow would consider it). Escalation risks are, of course, certain to inform Washington’s thinking (as well as that of other Western partners) about whether, when and how to follow London’s lead in loosening use restrictions.[2]

Kyiv and friends express frustration with U.S. incrementalism, arguing that it creates delays with battlefield costs.[3] Some say excessive deliberations meant that Leopard tanks and Bradley infantry fighting vehicles arrived after Russia had dug in behind minefields, too late for the new gear to make a great battlefield impact.[4]Relatedly, critics argue that Washington overreacted to Moscow’s perceived threats to resort to nuclear use in 2022, when Russia was on the back foot militarily, suggesting that the U.S. is still too easily bluffed by the Kremlin.[5] They worry that the Biden administration thinks that if Ukraine gains a decisive upper hand it could spook Putin and risk dangerous escalation – leading the U.S. to give Ukraine enough to survive but not enough to win.[6] Biden administration officials, however, categorically deny that such is their approach.[7]

The bottom line remains that the stakes of a war with a major nuclear power on one side and three major nuclear powers backing the other are tremendous. U.S. intelligence analysis, meanwhile, reportedly indicates that Russia has considered nuclear use during the conflict, casting doubt on arguments that all of Moscow’s nuclear talk is bluff.[8] Meanwhile, Moscow will certainly persist with its unnerving efforts to make its threats more credible. Putin’s 6 May announcement of tactical nuclear deployment drills as a response to what the Kremlin perceived as menacing moves by Western officials is a case in point.[9]Thus, careful risk assessment and incrementalism will likely continue to be the best approach to the delivery of new weapons systems given the risks at play.

Ukraine and its backers thus approach the summer of 2024 in a less than ideal but still viable posture. They face the simultaneous challenges of stopping Russia’s immediate momentum and girding themselves for a fight that could extend well over the horizon. The goal, though rarely if ever articulated so starkly, remains what it has been since the beginning: they want to head off a scenario in which Kyiv is forced either to surrender or to negotiate with Moscow from a position of such weakness that any deal would undermine not just Ukraine’s security but that of Europe as a whole.[1] Such outcomes remain avoidable. But Kyiv and its partners will almost surely need to make changes to enable Ukraine to fight on and puncture Russia’s confidence. The following six areas require particular attention.

For as long as the war continues, Ukraine will need ammunition and air defences. When its counteroffensive began, Ukraine was firing up to 7,000 artillery shells a day and Russia about 5,000.[1] In April, Zelenskyy said Russia is now able to fire ten times more artillery rounds than Ukraine.[2] Just how close Ukraine was to running out of ammunition before the U.S. Congress agreed to send more aid is not clear, but concerns about scarcity appear to have hindered its resistance of Russia’s advances in the counteroffensive’s wake.[3] Nor is a paucity of artillery shells Kyiv’s only problem. Russia has been pounding Ukrainian positions with thousands of glide bombs (dated munitions retrofitted with wings and guidance systems and fired by warplanes a safe distance away), taking advantage of Ukraine’s dwindling store of anti-aircraft munitions. 

The U.S. aid that is on its way will help replenish both Ukraine’s air defence munitions and artillery stocks, providing relief but leaving open the question of what will happen when they next run low, if Washington does not summon the political will to act. Given the headwinds that the 2024 aid package faced and the openly sceptical signals that Trump and his allies have sent about the value of the NATO alliance, Europe needs to actively hedge against two possibilities. One is that the U.S. will not come through next time for Ukraine. The other is that it will give less weight to the trans-Atlantic partnership. 

For Europe to both support Ukraine and hedge against the possibility of a less engaged U.S., it must fill substantial gaps. It will have to overcome hurdles from supply chain bottlenecks to shortages of explosives to the impact of inflation on defence spending. It must also surmount structural issues to develop sustainable EU-level coordination in procurement and defence industry activity.[1] Despite showing unprecedented unity since Russia’s full-scale invasion, Europe remains fragmented when it comes to aid and investment, with some countries spending more than others on defence – both at home and farther afield – and some giving more to Ukraine than others.

Trend lines are generally positive. European states are making progress toward increasing defence production. For instance, German manufacturer Rheinmetall, one of Europe’s most forward-leaning, expects to hike its annual throughput from 450,000 rounds up to 600,000-700,000 by 2025.[2] In March, the EU put €500 million toward making artillery shells in member state territories.[3] On 23 January, NATO signed a $1.2 billion contract to enable purchase of 220,000 155mm shells.[4] European states have also sought to address Ukraine’s need for air defence interceptors and replacements for weapons that have been worn down by use. The EU has revamped its multi-billion euro fund, the Ukraine Assistance Fund, to subsidise joint procurement from European defence firms.[5] 

But while Europe has made progress in contracting more arms, its states are not yet producing near the point where they can satisfy Ukraine’s needs and restock their own warehouses. These states will need to keep pushing to develop domestic capacity, coordinate better, level up defence spending and make hard decisions about when to entertain arms purchases from the U.S., even beyond systems such as Patriots, which only the U.S. can supply. (Buying more U.S. arms is, after all, probably a useful contingency, as well as a means of keeping Washington engaged.) Maintaining all these efforts amid the push-pull of domestic politics and as attention waxes and wanes will likely remain a challenge for the continent’s political leaders.

Striking the right balance with respect to the provision of advanced weapons systems to Ukraine will be another conundrum. On one hand, the goal of Western support is to help Kyiv persuade Moscow of the futility of its aggression; here, better weapons can only help. On the other hand, notwithstanding the criticism it has attracted, Western caution about sending more advanced weapons systems to Kyiv has been well advised. The potential for catastrophe in the event of escalation is not something to take lightly, and President Biden and his team have been – and should continue to be – guided by recognition of this reality.[1] The key to good decision-making will be dynamic assessment of escalation risks that incorporates lessons learned over the past two-plus years and close monitoring of what Russia’s internal discourse reveals about its threat perceptions.

Over the past two years, Russia has engaged in nuclear sabre-rattling both to prevent NATO’s direct participation in hostilities and to coerce Ukraine’s backers to cease their aid.[2] Against this backdrop, Western governments have had to use careful judgment in discerning when Moscow’s tough talk is bluster and where it is more than that, even as they recognise that Russia itself may not always know.

Western states would surely have behaved cautiously even without Moscow’s signalling because they are familiar with longstanding Russian doctrine that permits nuclear weapon use if Russia’s existence, or that of its nuclear arsenal, is at risk. A direct war with NATO members, which would create expectations of (if not actual) immediate strikes on Russian infrastructure and command and control, would likely be hard to contain at a level below that perceived threshold.[3] 

But divining Russia’s red lines when it comes to measures short of direct NATO participation in the conflict is more difficult. Moscow, of course, wants it this way. It has tried – through hints, threats and concrete actions – to convince Ukraine’s backers they are flirting with danger not just if they send troops into the fight, but also by dint of arming Kyiv. One component of its approach lies in reminders of its nuclear capacity and backing away from deals that constrain its behaviour in that realm. These include announcing that Moscow would cease observing the New START arms control treaty and de-ratify the Comprehensive Nuclear Test Ban Treaty (although it remains below the limits of the first and has not moved to carry out nuclear tests).[1] The Kremlin also said it would deploy nuclear weapons to Belarus and even allowed a lively civilian analytical debate about nuclear use, spurred by an expert’s proposal of nuclear strikes on Poland to bring Western states to their senses.[2]

Most recently, in May, Moscow cited Western “provocative statements and threats” when it announced non-strategic nuclear weapon exercises. In addition to these comments, Moscow threatened the UK conventionally, stating that if its weapons are used to hit targets on Russian soil, Moscow might well go after British facilities in Ukraine or elsewhere.[4]

Kremlin spokesman Dmitry Peskov later specified that Russia was especially frustrated with comments by French President Emmanuel Macron, British officials and “U.S. Senate” representatives.[5] Moscow is upset with Macron’s refusal to rule out direct French military involvement, which is best understood as performative ambiguation intended to keep allies cognisant of the stakes, French voters aware of his strong position and the Kremlin on its toes (just as Russia’s threats are meant to keep Ukraine’s backers nervous).[6]The Kremlin is also angry about British official statements in effect withdrawing opposition to Ukrainian use of UK-provided weapons to strike Russian territory. In the third case, the reference may be to House (not Senate) Democratic leader Hakeem Jeffries, a representative from New York, who said in an interview that a Russian win could lead the U.S. to send troops to Ukraine.[7] (Jeffries was speculating about what might happen if Russia emerges victorious and, in any case, was not speaking for the administration.)

So, how should Western powers think about Russia’s rhetoric? First, that Moscow cited the Macron (and perhaps Jeffries) comments underlines its own worries and strong desire to avoid direct war with NATO.[8] Here, its own record makes that even clearer. Despite early threats, the Kremlin has not, in fact, used a nuclear weapon. Had it used one, it would have been a spectacularly reckless move that would have unsealed the decades-long taboo against the use of atomic weaponry and opened the door to world-ending conflagration. (At the very least, it would have provoked a devastating response from the West and caused considerable upset with China and other partners.) Indeed, until now, it has also refrained from strikes, overt sabotage or cyberattacks on the territory of the alliance’s members.[9] Given that the Western powers fully grasp and appear aligned with Russia’s preferences when it comes to keeping NATO and Russian troops away from each other – whatever Macron and Jeffries may have said – Moscow has little to fear on that front, with or without threats. 

As concerns longer-range weapons, however, the calculus is less clear-cut and will likely be clarified only as all involved test one another. While Russia would like all Western military aid deliveries to Ukraine to cease, it is particularly worried about longer-range systems for two reasons. First, it is concerned about how such weapons might enhance Ukraine’s ability to do Russia harm in the future, regardless of how they are used now.[1] Secondly, and immediately, it frets that these weapons could do real damage to Russia’s military machine in the present war. With its new conventional threat against the UK, Moscow is sending the signal that it would see their use against its territory as cause to retaliate against a NATO member state (though it would likely start with the weapons supplied to Ukraine). Russia seems genuinely worried about the implications of these developments for its war effort. 

Another wrinkle here is that some of the weapons in question require donor state troops to accompany and operate them in Ukraine. Apparently, Germany’s bunker-busting Taurus missile is one such weapon. Germany’s concerns about providing Ukraine with the Taurus (which Kyiv sought for its superior capacity to destroy infrastructure, likely with thoughts of doing severe damage to the Kerch bridge connecting Russia to Crimea) had echoed the U.S. discussion of ATACMs, focusing on the escalatory risks inherent in Ukrainian strikes on targets in Russia and Crimea.[2] But in March, amid mounting pressure on German Chancellor Olaf Scholz, including from his own defence minister, to send these missiles to Ukraine, a Russia-leaked conversation between German officials indicated that Berlin fears it cannot provide them absent German military personnel. Scholz thinks that dispatching personnel would make Germany a combatant and invite dangerous escalation.[3] The Russian threats against the UK may suggest Moscow believes that missiles it provides are operated by British military personnel. 

There is no easy answer to the complex problem of managing the risk of providing advanced weapons systems. While the record suggests that Moscow does not mean all it says, there is no reason to think all its threats are empty. At the same time, giving Moscow a full veto over supplying Ukraine the weapons it needs to succeed on the battlefield is not a reasonable way forward. Western governments should thus continue to look for responsible ways to give Ukraine what it needs and strive to better coordinate among themselves as they adapt their policies. 

Although no policy, save capitulation, can entirely remove risk from these dynamics for any party, the lessons of the first two-plus years of conflict suggest that incrementalism helps leverage the Kremlin’s own risk aversion to enable further deliveries. Should Western arms suppliers decide to move forward with lifting caveats, sticking with a calibrated approach would be prudent. Western powers might thus get rid of some restrictions, but keep others in place, for instance limiting Ukrainian strikes in Russia to unquestionably military targets (rather than, for example, infrastructure) and communicating this policy to Moscow. Careful deliberation, and methodical analysis to anticipate Russia’s response, will require paying a price in the form of delay and the political fallout that results. But, given the stakes, this way ahead is the most prudent. 

Moscow, meanwhile, will continue trying to coerce changes in Ukrainian and Western behaviour, but its specific actions will also provide evidence of its real capabilities and risk tolerance, which could help Ukraine and its backers calibrate their own next steps. For instance, if the UK and Ukraine do test Russian wherewithal, Moscow’s response will help elucidate its true red lines. 

Another potential tactic for risk mitigation relates to Russia’s insistence that its concerns are not just about the present conflict, but also about the arsenal Ukraine is building for the future.[4] If this worry is indeed significant in Russian officials’ minds, there may be a way to quietly signal to Moscow that, if and when talks to end the war commence, limits on this sort of weaponry could be on the table. Of course, if Russia dictates terms, Ukraine would lose these weapons. But even if it does not, Ukraine might consider limits in exchange for concomitant restrictions on Russia. While it is unclear if sketching this prospect would mitigate Russia’s present-day threat perceptions, it could only help and seems worth trying. 

No amount of weaponry, advanced or otherwise, will do Ukraine any good if it lacks the soldiers to wield the arms. Kyiv is struggling to mobilise and adequately train front-line troops to replace the dead and wounded and spell those exhausted by long stretches of combat.[1] While Zelenskyy announced in late February that Ukraine had lost 31,000 soldiers in two years of fighting, this number reflected only the casualties whose deaths in combat and identities were confirmed.[2] U.S. officials estimated that 70,000 Ukrainian soldiers had been killed as of the summer of 2023.^[3] The challenge goes deeper than finding new fighters: it also has to do with the morale, physical fitness and training of conscripts, who in many cases fear that they are being shuffled off to battle without sufficient support for them and their families. “The military now no longer recruits the people who want to fight but those who do not want to refuse”, a former senior defence official said.[4]

Coming up with a new mobilisation framework that corresponds to current reality has proven complicated. In late 2023, Ukraine’s armed forces said they needed half a million new recruits.[5] But a government bill to reform mobilisation, introduced around the same time but not geared to any specific number, was stuck in parliament for months before finally being signed in April 2024. The new law, which entered into force on 18 May, was proposed by the defence ministry, but has been much amended in the course of parliamentary debate.[6] It seeks to widen the pool of recruits, including by obliging conscription-age men to update their data and reassessing the “unfit for service” status of some men previously rejected.[7] Prior to its passage, Zelenskyy signed an older bill into law which lowered the minimum age for mobilisation from 27 to 25.[8] The high mobilisation age was an artefact of Ukraine’s now irrelevant conscription regulations, under which men are subject to be drafted until the age of 27 and those over that age to be mobilised. 

The mobilisation bill moved slowly for several reasons. Zelenskyy and his team worried that provisions broadening the pool of people subject to serve would be unpopular.[9] The president has also asked the military to explain why it needs so many fighters and highlighted the risk that large-scale mobilisation could aggravate labour shortages.[10] A member of Ukraine’s parliament furthermore told Crisis Group that legislators felt the new mobilisation law could not widen the aperture too much, for instance to even younger men or more women (women in a lengthy list of professions are subject to being drafted on paper, although they are rarely if ever called up), in order to leave space for future expansions of the force.[11] 

The president’s worries about unpopularity are surely rooted partly in wide-spread reports of draft evasion. Crisis Group has for months heard accounts of men failing to respond to mobilisation notices.[1] Reportedly, somewhere between tens and hundreds of thousands of military-eligible men have fled the country, although the wide range reflects how difficult it is to get an accurate count.[2] According to a BBC investigation, those who flee bribe border guards to ignore the exit ban for men between the ages of eighteen and 60, or to give them papers saying they have a disability.^[3] “If you have hands and feet, you end up paying a bribe at every checkpoint [to avoid being drafted]”, a businessman complained.[4] To fill their billets, recruiters have been accused of using coercive tactics, sometimes illegally detaining men and compelling them to enlist. Units have also taken to freelancing, recruiting personnel directly into their own ranks with promises of good support and treatment.[5] 

Corruption is recognised as a problem. Ukrainian media regularly report corruption cases involving mobilisation officers and medical commissions.[6] The army command recently ordered an investigation into a senior secret service officer, who tried to use a draft notice to silence a journalist working on a story about the officer’s surprising wealth.[7] President Zelenskyy also cited corruption in August 2023, when he fired every regional recruitment chief.[8] 

Zelenskyy was also right to ask the military to explain its needs. It is hard to get a sense of just how many military personnel Ukraine has and what they are doing. Accounting is certainly inadequate, and indeed one of General Syrskyy’s early administrative acts was to commence an audit of the armed forces.[9] Ukrainian officials and experts told Crisis Group that despite the draft dodging, the country has some one million people in uniform, if not more. But while the number is high, the military’s fighting strength is insufficient to hold the front line. Support units, they say, are well staffed; it is combat forces that face persistent troop shortages.[10] Although units may look good on paper, they may not have their full reported complement because they have been pressed to accept mobilised personnel who were not, in fact, ready to fight for health or other reasons.[11] Attrition then takes its toll. Some front-line battalions are down to a fraction of their previous strength, with one commander telling the Washington Post his unit dropped to 40 from 200.[12]

According to both officials and experts, prospective soldiers avoid service in general and front-line service in particular because they fear that they will not be adequately trained and equipped. They also worry that, if they are wounded, they will not get battlefield and further medical care and that, if the worst happens, their families will not get help. These are not idle concerns. Training gaps are very real, and as discussed below, battlefield medicine reportedly continues to struggle. Crisis Group has heard of families facing great difficulties trying to learn the fate of loved ones.[13]

Defence ministry officials have talked of shifting from a system of mobilisation to one of recruitment. They do not want to end mobilisation, but to make signing up, whether when called or voluntarily, more appealing. They will need to enhance the benefits available to soldiers and their families, ensure that they get care and attention when they are wounded or otherwise need support, and, while providing a revamped training to everyone, offer volunteers more options regarding where and how they serve.[14] A transparent system of rotation in and out of the most dangerous combat zones and clarity about who is allowed to leave the army could also ease fears among prospective recruits. The military command and government removed provisions for clearer troop rotation and demobilisation frameworks from the mobilisation bill just before it came up for a vote.[15] These should almost certainly be revisited and resuscitated.

Even if officials commit to it, rolling out a new approach will take time, and Ukraine needs front-line fighters now. Ukraine’s plans underline its challenges: rather than pulling from the better-staffed rear units to reinforce the front lines, an official said Kyiv will likely draw on other uniformed services.[1] So far, there is no evidence it has done so, but it may take this step soon. It is does not seem that Syrskyy’s audit has turned up much in the way of trained units languishing untapped in the rear. 

Kyiv will undermine its own goals rapidly if it proceeds with mobilisation without fixing the problems of service. In the very near term, it may have little choice but to muddle through, although some measures, including more transparency with both servicemembers and their families, can be taken rapidly. Indeed, even the promise of a better way forward may make it easier for soldiers to serve. 

When it comes to training Ukrainian forces, the problems are twofold. One is that not everyone sent to the front gets more than a cursory version of the preparation they would optimally receive. Crisis Group has heard tales of people sent into battle with only days of training.[1] “Mobilised troops receive very little training because they are desperately needed on the front”, said Konrad Muzyka, a Poland-based defence analyst. “It is a vicious circle. … Poor training results in more deaths, which results in more fragmentary mobilisation”. Some pay for their own first aid classes ahead of deployment.[2] Others join basic training courses for civilians provided by municipalities. Anecdotally, the vast majority of participants in these courses are women, some of whom intend to enlist. Others may want to be better able to protect themselves and their families with the men away.[3]

The second problem is that even longer-term training in its current form may not be adequate to Ukraine’s needs. Not surprisingly under these conditions, knowledgeable Ukrainians in and out of uniform point out that not only are there gaps in combat preparation, but that units in the rear are also consistently unprepared to fight, limiting their capacity to backfill combat units and to hold on if Russian forces break through Ukraine’s lines.[4]

The gap does not stem from lack of support from outside partners. Ukraine is getting substantial training assistance. All but three of the EU’s 27 members, plus Norway, Türkiye, Australia, North Macedonia, Iceland, Albania and Serbia, have offered training or instructors.[5] The EU’s Military Assistance Mission expects to train some 35,000 troops by the end of 2024.[6] The U.S. had drilled some 19,000 by early 2024, and the UK has prepared some 30,000 in Britain, with another 10,000 planned for the first half of 2024.[7] 

The problem is more the training’s content and pace. The core of what friendly states provide is a five-week, NATO-style combined arms course.[1] But the fighting itself is simply different – and more brutal – than the course assumes. Ukrainian recruits complain of long PowerPoint presentations and lectures on safety regulations that preclude realistic training.[2] They also say the curriculum fails to capture battlefield conditions in Ukraine. For example, it does not appropriately account for lack of air support and the proliferation of drones and jamming equipment.[3] Military experts say training has been too brief for the rank and file and too slow for higher-level staff.[4] One adviser to Ukraine’s armed forces told Crisis Group that while foreigners drill Ukrainians abroad, up to 60 per cent of its own trainers sit idle.[5] Experts and journalists report that units often carry out their own training, some of it better, some worse.[6]

Ukrainian military advisers and senior staff have proposed alternative approaches. Among the ideas worthy of consideration is a division of labour under which foreign training would emphasise developing non-commissioned officers (NCOs), who carry the military’s administrative burden, as well as imparting skills in leadership, military medicine and specific weapons that Ukraine has lacked.[7] Ukrainian trainers could then design courses that reflect battlefield conditions. Further, military advisers have suggested that Ukraine’s trainers should have their own rotation system, so that they can develop skills and get needed breaks.[8] A retired senior Western military official said Kyiv might consider having Ukrainian trainers also rotate into combat duty, so that they have recent firsthand battlefield experience.[9] Importantly, Western trainers and their Ukrainian counterparts should establish mechanisms to ensure they learn from each other.[10]

For the long term, Ukraine needs a training plan that is not only better adapted to what troops will face when they get to the front but also begins to prepare the fighting army Kyiv and its backers hope to build over the next two to five years. NCO training will be critical to both. But so will training on weapons that will require long lead times, such as F-16 fighter jets, which Ukraine has sought from the start of the full-scale war and are now expected to enter combat later in 2024, after pilots have been trained abroad.[11] “We could have started training pilots a year ago”, a German official said in September 2023, shortly after training had begun. “We knew we would get there at some point”.[12] Of course, with debates proceeding, one cannot really know where, exactly, Ukraine’s backers will get. But where agreement has been reached to provide weapons (or when it seems very likely) the training should surely begin as soon as possible. 

In the spring of 2024, in the face of Russian advances and Ukraine’s constraints, Ukrainian forces rushed to build defensive fortifications along key stretches of the front in what Zelenskyy described as a “new phase” of the war.[1] A variety of military and civilian observers within Ukraine and without understandably bemoaned the military’s failure to beef up such lines sooner.[2] Because that was not done, they argued, forces falling back under Russian pressure might have nothing to fall back to.

While Ukraine has now reportedly made substantial and rapid progress on defensive lines, gaps remain.[3] Filling them is crucial, as Kyiv will almost surely find itself in a defensive posture for some time to come. Its supporters are encouraging it to focus on holding the territory it has now, to put it in a stronger position to keep inflicting losses on Russian forces and to guard against the risk of a Russian offensive while it regroups. A Western official prescribed a strategy of “active defence”, whereby Ukraine keeps probing for weak spots and steps up its missile and drone attacks.[4] This idea seems the most plausible forecast of what Ukraine will do, assuming it can hold the line, until it is able to go on the offensive once more.

Ukraine will also, of course, do all it can to keep the pressure on Russian forces, even when it cannot break through their lines. The successes of its asymmetric warfare tactics in 2023 continued in the first part of 2024. In the first months of the year, these have included the use of naval drones to destroy a Russian missile boat on 1 February, sinking a patrol vessel on 5 March and damaging three ships moored in Sevastopol port on 23 March using cruise missiles. The Ukrainian air force also downed a Russian spy plane on 15 January and likely destroyed six fighter jets in a 5 April drone attack on an airfield in southern Russia.[1] The UK’s defence ministry said losing one of its eight A-50 spy planes, most likely to a Patriot missile, will likely require Russia to think twice about reconnaissance flights near Ukrainian-controlled airspace.[2] 

But Kyiv must prepare for what fighting defensively will mean and, anticipating a long war with Russia, plan for both defensive and offensive operations in the future. It must also recognise, and not just rhetorically, that its tactics will not always work. It needs to integrate undesired contingencies into its planning and not just prepare defensive lines, as is now under way, but also ramp up planning for civilian evacuation and support. While local authorities Crisis Group spoke to in eastern Ukraine in March took pride in the systems they had in place to support evacuees, they did not seem to be laying groundwork for ramped-up efforts if Russia takes more territory.[3] Nor were many humanitarian groups thinking about potential relocation needs (which in the past have required evacuations of civilians under fire) or the challenges of continuing to provide assistance if things grew more dire.[4] In May, as Russian troops moved forward in the Kharkiv region, the humanitarian response indeed struggled to keep up.[5]

Thus, for all the lessons of the past months, a certain amount of wishful thinking appeared to remain part of the calculus in Kyiv and among its partners. Sustainability will require a more clear-headed approach, as well as for Ukraine and its backers to hash out a coordinated strategy, in which aid and training schemes align with Ukraine’s military planning and a variety of possible contingencies.

While real peace talks are implausible under current conditions, Ukraine and its backers should also be thinking about how to help shape the battlefield to make them more likely in the future. This task will not be easy, with Russia seeming bent on continuing the war and gaining from it. But should the Kremlin cease to see quite so much advantage in further fighting, it would be more likely to cut a deal that does not undermine Ukrainian, European and global security.

To date, Kyiv’s diplomatic strategy vis-à-vis Moscow has emphasised accountability and international legal mechanisms rather than deals. That is to say, Ukrainian officials have pressed their backers and partners to pursue charges against their Russian counterparts in international courts, agree to use frozen Russian assets to aid Ukraine and raise questions about the legitimacy of the Putin government (which has, after all, repeatedly changed the Russian constitution to remain in power). It has also focused on broadening global support for Ukraine, including through the series of summits and senior leadership meetings convened around the world to discuss the Ukrainian government’s “peace plan”. Kyiv hopes the next meeting on 15-16 June, hosted by Switzerland in the lakeside resort town of Lucerne, will gather heads of states in a show of support. But the participation of key countries remains unclear with less than a month to go.[1]

That these meetings do not, of course, include Russia and that the plan is a plan for Russian retreat and acceptance of defeat is intentional. Kyiv’s target with this engagement is not Moscow, but capitals around the world. As such, outreach that underlines Russia’s violation of Ukraine’s territorial integrity in contravention of a cardinal principle of modern international law as memorialised in the UN Charter indeed finds sympathy globally.

But Ukraine risks losing some of the global good-will it has by pressing on in this way, if only because the results are so minimal, and few leaders want to attend meetings for the sake of doing so. Moreover, Ukraine is far from the only deadly conflict on the planet, and frustration with the outsize attention it continues to draw has only grown over the last two years. Previous meetings have revealed divisions over perceived double standards (with Gaza getting frequent mention), the lack of Russian participation and, in the words of a European official, Ukraine’s approach of “pushing too hard, as usual”.[1]

At the same time, Kyiv does talk to Moscow, even if not at these summits. Although the UN- and Türkiye-brokered Black Sea grain deal lasted less than a year, it did underline that common interests could keep the parties talking, even as they fought. Ukraine and Russia have met to discuss exchanging prisoners of war and remains of dead soldiers. They have also arranged for the return of Ukrainian citizens from Russian territory, including children.

These discussions are not groundwork for a broader deal, by any stretch. But they demonstrate that mitigation of some of the war’s damage remains possible. In principle, the parties could also discuss rules of the road for warfare, such as avoiding strikes on energy infrastructure. Although at this point both Ukraine and Russia have much to gain from strikes on Russian oil industry and Ukraine’s overall grid, respectively, at a later time, they might consider agreeing to step back.

Ukraine’s backers also talk to Russia. Here, they cannot by any means make a deal on Ukraine’s behalf. But they can remind Moscow that deals on Ukraine that Kyiv can live with open the door to broader discussions of European and global security. Finding a way to make what looks set to be a long standoff between Moscow and Western capitals less unstable and less expensive would serve all parties' interests.

Despite the U.S. Congress’s recent show of unity, Moscow has reason to look back at the last year with satisfaction and the sense it is on the right track. Even with the resources that the U.S. is now putting into the assistance pipeline, the Kremlin’s battlefield gains can only reinforce confidence in its staying power – and that is just part of the picture. The Kremlin tightened its grip at home following the would-be revolt by Wagner forces, and it is doing so again in the wake of the deadly ISIS attack at the Crocus City Hall concert venue in late March.[1] Mass anti-war protests are unlikely, and if they come will almost certainly be met with crackdowns, not policy shifts. U.S. elections are only months away; polls suggest that Trump has at least even odds of returning to the Oval Office brimming with animus toward Zelenskyy and scepticism about support for Kyiv. Even if Biden prevails, it is possible that Washington will grow fatigued with propping up a far-away protagonist in what some commentators already describe as another “forever war”.[2]

Equally importantly, if Ukraine and its supporters cannot both adapt and maintain their resolve, Kyiv will almost surely continue to lose lives and territory. It will then eventually have little choice but to cut some sort of deal. A Moscow in a position to dictate terms will certainly look to deny Kyiv’s capacity to rebuild its military and defend itself in the future – or to get help from partners. The Kremlin may well also demand European commitments to limit promises to defend (much less extend NATO or EU membership to) not only Ukraine, but also other states in Moscow’s crosshairs, notably Moldova and Georgia. At best, its own losses may render Russia sufficiently chastened not to trot out demands it made in late 2021, prior to its full-scale invasion, when it sought to constrain NATO’s ability to station forces to defend allies who had joined the alliance since the Cold War ended. But NATO members near Russia’s borders fear it will do all it can to undermine their security and the alliance’s unity.[1] 

While any negotiated deal that ends the war will give Russia concessions, if it emerges with the appetite for greater aggression because of the scope of its success, the result will be a Ukraine and a Europe prone to instability. A Russia with a larger army than before the war and able to bend Kyiv to its will could well press its advantage, most likely first against Moldova and Georgia but eventually perhaps, as many NATO members that border Russia fear and believe, against their own territories.[2] Threats that draw closer to the alliance’s eastern flank will likely be met with recriminations among NATO and EU allies faced with hard questions about these institutions’ credibility when it comes to mutual defence. Some will insist on more forceful responses to new Russian aggression, military or political, than those of the last two years, increasing escalation risks. If the U.S., perhaps under a second Trump administration, shows waning seriousness about its commitments to European security, the risks for the region will be even more dire.

Russia’s big bet on aggression is most likely to fail if Ukraine and its backers learn the lessons of the past year as Kyiv prepares to fight for its future. The U.S. will need to summon the political will to provide the support that only it can offer. European countries will need to step up to ensure that their assistance can help Ukraine survive the U.S. stepping back, even as they do what they can to prevent that from happening. All will need to work together to position Ukraine as strongly as it can be to defend its territory – with the right weaponry, troop strength, training and field posture to hold the line. 

Ukraine, meanwhile, will need to dig in as it fixes its broken recruitment and deployment system, revamps its approach to training and prepares its population for a continuing war even as it signals its openness to meaningful diplomacy. The strongest card in its hand is asymmetric tactics, such as its strikes in the Black Sea, that chip away at Russia’s capacity to do harm and perhaps its morale. Moscow’s return to nuclear threats in May suggests that it is not as pleased with the state of affairs as its rhetoric suggests and is genuinely worried about the implications of greater Western assistance. It will be for the Western governments and their intelligence services to assess perils associated with delivering advanced weapons systems, but those risks should not be dismissed out of hand. All involved should embark upon the next months of war clear-eyed and prepared to mitigate dangerous contingencies even as they look to take advantage of openings to end the war on more favourable terms should these appear.

Finally, even as Ukraine prepares for a long war, Kyiv and its backers should keep front of mind that the end goal of their efforts remains diplomacy, which implies compromise and long, painful negotiations. That means keeping the fight going until Moscow is interested in a deal that not only ends the shooting, but limits Russian capacity for future aggression, perhaps in exchange for constraints on Ukraine and its backers’ capacity to do Russia harm. It is worth preparing for this eventuality, with all parties assessing their true red lines, even if behind closed doors. Signals of willingness to mitigate the damage, such as through mutual agreement to refrain from attacking energy infrastructure, could also be valuable in the meantime. While such initiatives may fail, an openness to creative solutions that undermine neither party signal that both smaller and larger deals remain possible, even if, for now, peace talks involving the genuine give-and-take required to end the war in a way that does not create more danger seem out of the question.

Kyiv/London/Washington/Brussels, 27 May 2024