Ukraine And Beyond: Shaping Europe’s Security Future

What’s new? Russia’s full-scale invasion of Ukraine has upended European security and created a reality in which EU and NATO member states, on one side, and Russia, on the other, view each other as fundamental threats, even as the United States is poised to become a less reliable partner for its allies.

Why does it matter? An unstable Europe has economic and security repercussions globally, not least given the nuclear capabilities of Russia, on one hand, and NATO on the other. A deeper understanding of assumptions and threat perceptions on both sides can help key players manage the risks of an increasingly militarised region.

What should be done? Diplomacy and deterrence are both required. Kyiv’s backers should seek a settlement to the war that ensures Ukraine’s continued capacity to defend itself. European allies should reduce reliance on the U.S. and – together with Washington – pursue risk mitigation with Russia through limits on weapons deployments and other activities.

Executive Summary
Three years ago, Russia’s full-scale invasion of Ukraine upended assumptions that underpinned European security for decades – leaving both Ukraine’s fate and Europe’s future in the balance. While the conflict has seesawed, Moscow is now making slow, painful gains in Ukraine’s east. EU and NATO states, convinced that Russia poses an enduring threat, wary of escalation and uncertain of U.S. policy, are backing Kyiv, but lack a clear way forward. Neither side has an attractive path to achieving its objectives – in Ukraine’s case expelling Russia and in Russia’s gaining sway over Kyiv and positioning itself to wield influence beyond. Obstacles to a peace deal or even ceasefire are formidable. Still, a change of U.S. administration might offer a chance to break the deadlock by drawing on Washington’s leverage and that of Ukraine’s European backers. The most durable outcome would leave Ukraine sovereign; Russia chary of the costs of renewed aggression; the European bloc more self-reliant; and all parties ready to discuss how to mitigate risks on an increasingly militarised continent.

Since February 2022, Russian and Ukrainian fortunes have been on a roller-coaster. The surprises began with Russia’s all-out invasion. Initial shock then yielded to that of watching the feared Russian army fail to capture Kyiv and instal a Kremlin-friendly government. But Moscow stuck with its political aims – a pliant Ukraine and a renegotiated European security order – while turning its military focus to scrabbling for territory in the Ukrainian east and south. The seeming stalemate that followed put Ukraine in a bloody fight for its sovereignty, aided by funds and weapons from the West, with the U.S. a key supporter. But, by early 2025, that had changed. Russia is now making hard-won but steady progress. At the same time, Ukraine is short of soldiers, and Donald Trump – who in the past voiced scepticism of support for Kyiv – has returned to the U.S. presidency.

What happens in Ukraine matters far beyond its borders. For decades, Moscow has described the U.S.-led West as a threat to Russian national security, arguing that Western efforts to weaken Russia were reasons for both beginning the war in Ukraine in 2014 and escalating to a full-scale invasion in 2022. Since then, the Kremlin has made clear that it sees war in Ukraine as necessary, but not sufficient to what it believes will be a long-term project of countering its adversaries. NATO and EU members, by contrast, had been divided on the Russian question until 2022, with some (particularly on the bloc’s eastern flank) viewing Moscow as an existential threat and others (including the U.S.) seeing any danger as contained. But since the all-out invasion in 2022, these states have been close to united in perceiving Moscow as a menace that they must be able to deter and, if all else fails, defeat. They also know that U.S. retrenchment – a real possibility as Trump recalibrates priorities – will make that goal a great deal harder.

Leaders across Europe have good reason to see an emboldened Russia as a danger.

Leaders across Europe have good reason to see an emboldened Russia as a danger. Russia’s perception of a West bent on its destruction leads it to view neighbourhood domination as imperative. The boundaries of this vision do not stop at Ukraine. Should Russia achieve its goals there, it could push on to Moldova and beyond. Indeed, countries backing Ukraine worry that Russia could, if more confident, threaten NATO members. Each Russian test of Western resolve could risk a new crisis. Because Russia and three of the countries it counts as adversaries (the U.S., France and the UK) all possess nuclear weapons, each crisis would carry terrifying escalatory potential. Avoiding such crises altogether may not be possible, but Western powers will be best positioned if they work together to contain the risks of a changing security order through a mix of diplomacy and deterrence.

The most immediate diplomatic challenge is trying to settle the conflict in Ukraine, which now crowds out broader discussions. Given Russia’s battlefield momentum and Trump’s scratchy relations with the United States’ traditional trans-Atlantic partners (emblemised by his efforts to coerce Greenland away from Denmark), not to mention the U.S. president’s seeming affinity for Russian leader Vladimir Putin, it is hard to be optimistic.

Yet there is at least an opening for progress. Fears that Trump would cut all support to Ukraine and undermine incentives for negotiation have quieted with the news that his team sees a six-month (some have said 100-day) window for reaching a deal. That time can be put to good use. Trump should take Putin up on his avowed willingness to talk face to face, coming ready to use U.S. advantages. These include Moscow’s desire for a deal with the world’s strongest country and its fear of U.S. capacity to make things worse for Russia, including through additional sanctions, which Trump has threatened. A further U.S. strength is the ability to marshal the support of its European allies. Trump should use this too, coming to the table with their backing and ready to protect their interests. True, thus far there is no sign that Putin will give up on or postpone his goal of vassalising Ukraine, but Moscow has also been waiting to see what Trump will do: if he plays his hand well there may be a chance Moscow will opt for concessions. The most stable settlement would see Ukraine remain politically independent and able to defend itself, even if Russia retains de facto control of territory it occupies.

Regardless of what comes next in Ukraine, Kyiv’s European backers need stronger militaries and a resilient defence industry to deter Russia. While these countries see their security on the line, Trump’s team wants to pull back from Europe and refocus on challenging China for primacy in the Indo-Pacific. The European allies need to face the inevitability of this transition and work, ideally with the U.S., to make it happen – a big but not insurmountable task, especially if Washington recognises its interest in bulking up EU and NATO arsenals.

Finally, even as both sides ramp up in the interest of deterring each other, they need to be aware of the risks of doing so. Heightened by Russia’s long-standing in-security about the West and its European neighbours’ corresponding fear of Rus-sian aggression, the challenges of European security will not go away, however the Ukraine war ends. The region’s countries can be expected to palliate their sense of vulnerability through arms buildups, which are liable to create uncertain deter-rence at the cost of increased risk and expenditures. These can be managed – though not eliminated – by working together to develop arrangements to contain the danger, including escalation, of regional militarisation. Moscow, no less than the trans-Atlantic countries, has a lot to lose from an expensive buildup rife with uncertainty.

This is, admittedly, an aspirational vision for reaching a new European security order but one that, for all its risks, comes to rest at a place of plausible stability. Achieving this vision would require Washington and European capitals to remain reasonably aligned – hardly a foregone conclusion given Trump’s penchant for strongarming allies – so that they can convince Putin the costs of a maximalist approach are for the moment not worth absorbing. Success may also require that the Kremlin is experiencing enough economic and political stress that it opts for deal-making. If these pieces do not fall into place, then the aspirations for peace in Ukraine and a stable future order will take a back seat as, on one side, Russia and, on the other, Ukraine and Europe – with or without U.S. support – gird themselves for a longer war, greater costs and growing escalatory risk. Mapping out the best way to manage those scenarios is beyond the scope of this report, which focuses instead on making the most of the openings that present themselves today.

Kyiv/London/Washington/Brussels, 1 February 2025

I.Introduction
No longer a stalemate, the war in Ukraine has evolved into an attritional conflict in which Russia has the upper hand, but not a clear path to victory. Following the failed Ukrainian counteroffensive in 2023, Russian forces have slowly but steadily gained ground. Yet these advances have come at enormous human cost to the Kremlin: all told, its army has likely suffered over half a million deaths and injuries since the all-out invasion.1 Russia has also paid in other ways. U.S. and EU member state sanctions are taking a bite out of the Russian economy, even if they have not dealt the decisive blow for which Western leaders hoped. A distracted Moscow failed to stop rebels from ousting Russia’s long-time partner in Syria, Bashar al-Assad, at the end of 2024.

As for Kyiv, it is not in a good place. The Ukrainian people are tired of war, and the military is fighting a bigger, more powerful adversary. Ukraine is struggling to mobilise and train the forces it needs, even as a surprise push into Russia’s Kursk region in August 2024 diverted troops from its eastern front, where Moscow is gaining. Ukraine’s defences are not on the brink of collapse, but Kyiv would benefit from a breather, even if most Ukrainian proponents of a respite say they want it not to attain an end to war, but to regroup to fight another day.2

The bigger worry for Kyiv and its European partners will be Putin’s desire to render Ukraine a demilitarised and, in effect, defenceless vassal state.

Enter new U.S. President Donald Trump, who has promised a deal to end the war. Whether he can broker one is anyone’s guess. Fundamental issues separate Russia from Ukraine and its backers. The issue is not so much whether Russia will yield control of the land it occupies. Few, even in Kyiv, expect Moscow to relinquish its hold on this territory, which represents roughly 20 per cent of Ukraine’s total landmass, any time soon.

The bigger worry for Kyiv and its European partners will be Putin’s desire to render Ukraine a demilitarised and, in effect, defenceless vassal state. They do not trust Russia to rest within its boundaries if it sees Ukraine’s political independence available for the taking. Nor do they think Moscow will confine its strategic ambitions to Ukraine, worrying that Moldova could face growing harassment, and beyond that the countries on NATO’s eastern flank. Further complicating the picture, Trump has put the U.S. commitment to allies into question with his insistence that he will either purchase or otherwise “get” Greenland from Denmark, as well as his threats of tariffs on the EU and its members.3

Whatever happens, both European security and Ukraine’s future are being re-defined by this conflict, and both will be shaped by the new surge of diplomacy that is just beginning. Against this backdrop, this report explores the assumptions and threat perceptions that have emerged from and driven the war in Ukraine and that will define the emerging European security order. The report also shares pro-posals for grounding policy in more realistic expectations. As far as assumptions, the report operates from the premise that – for all the disruption of trans-Atlantic relations that flow from the new administration’s recalibration of U.S. foreign policy – the U.S. and its European allies will remain more or less aligned with respect to Ukraine. This assumption could well prove false, and there are myriad other ways in which Trump’s unpredictability or Putin’s intransigence could scuttle efforts to resolve the conflict and bring greater stability to the region. How to manage the challenges that Europe would face if talks collapse, or do not get started at all, is outside this report’s scope.

The report builds on prior Crisis Group reporting on European security and, since 2014, the conflict in Ukraine.4 It draws from over two years of research and dozens of interviews. Among the interviewees were officials, diplomats, parliamentarians, activists and specialists in and representing Austria, Belarus, Belgium, Bulgaria, Canada, Denmark, Estonia, Finland, France, Germany, Hungary, Ireland, Latvia, Lithuania, Moldova, the Netherlands, Poland, Portugal, Sweden, Russia, Türkiye, Ukraine, the UK, the U.S. and other states in the region and the world, as well as representatives of the EU and NATO. The gender breakdown of interlocutors loosely reflected the representation of different genders in security policy in these countries.

II.Misguided Assumptions
The full-scale war in Ukraine that Russia began on 24 February 2022 has been marked by faulty bets and assumptions on the part of those involved. While some have been discarded, others persist and continue to guide behaviour.

A.Off on the Wrong Foot
Start with Russia: in the lead-up to the invasion, Moscow seems to have assumed that a well-prepared Russian military would encounter cooperative regional and local Ukrainian officials and a complaisant Ukrainian population, while Western capitals would be cowed.5 This last was meant to be assured by Vladimir Putin’s public threat, as the invasion got under way, of “consequences … such as you have never seen in your entire history” for anyone who interfered.6

The Kremlin was mistaken on all counts. Ukrainians, who had been at war with Russia since 2014, were primed to resist. The Russian armed forces, though perhaps better trained than they had been previously, had inadequate gear, the result of a system hollowed out by corruption.

Russian soldiers were sent to war with unworkable plans for victory.

In part because their leaders assumed Ukrainians would not fight, Russian soldiers were sent to war with unworkable plans for victory. While some Ukrainian officials may have been inclined to cooperate with Moscow, most were not.7 Western states saw in Russia’s aggression a threat to their own security, and despite Putin’s language, they judged the Kremlin unlikely to escalate to nuclear use if they aided Ukraine. Western leaders took care to avoid actions that might lead to a clash between NATO and Russian forces, reflecting longstanding assessments that such a direct confrontation would hold unacceptable escalation risks. But they also quickly decided to provide Ukraine with intelligence, money, weapons and military training.

If Moscow got its initial assessments wrong, Western and Ukrainian expert circles also misjudged the situation. At first, they shared Moscow’s opinion that it would win, albeit perhaps not as quickly or easily as the Kremlin expected.8 These experts based their analyses on Moscow’s own reporting on its capabilities as well as on its successes in Syria and Ukraine between 2014 and 2022. There were differences among experts: some argued that Western states should be willing to take more risks to even the odds for Ukraine, for instance with the no-fly zone that Kyiv sought.9 Others, including Crisis Group, advocated for (among other things) arms-length aid focused on weapons to assist in Ukraine’s defence.10 But in those early days, experts in both camps generally failed to foresee that Moscow’s onslaught would sputter so haplessly and that Kyiv, assisted by Western weapons and intelligence, would be able to force a Russian retreat.

B.Persistent Wagers
1.Russia: Two big bets
Russia adapted its strategy after many of its best troops perished in a foolhardy multi-pronged drive on Kyiv in the first days of the all-out invasion.11 It is now effectively, if bloodily, focusing on attrition warfare and gaining ground. But its approach to the conflict continues to integrate at least two questionable assumptions.

The first is Moscow’s continued belief that nuclear sabre rattling can yet force Ukraine’s backers to desist. While most Western leaders judged from the start that nuclear escalation would be a real risk if NATO members and Russia were to clash directly, they generally did not view the threat of Russian escalation in the face of military aid as credible, even when it became more palpable. A key moment came in the fall of 2022, when U.S. government analysts assessed that Russia might resort to nuclear use in Ukraine to reverse a series of battlefield losses. Rather than cut off assistance, U.S. officials outlined the consequences Moscow would face if it used a nuclear weapon, which reportedly included the use of conventional weapons to destroy Russian forces in Ukraine, and Russia backed down.12 Nonetheless, Moscow has since repeated the menacing rhetoric and both official statements and Russian expert analyses reveal frustration with its failure to deliver as desired.13

Since 2014, ... the trans-Atlantic consensus on Ukraine – and thus both material support for Kyiv and policies such as sanctions on Russia – has held.

Russia’s second dubious bet is that Western unity in backing Kyiv will fall apart. To be fair, Westerners themselves seem to consistently doubt their ability to hang together and, at times, they have come close to splintering – notably when the U.S. Congress deliberated for months before passing a critical support package in April 2024. But since 2014, when Russia first invaded its neighbour, despite numerous debates and political shifts within countries (including the four years of Trump’s first presidential term), the trans-Atlantic consensus on Ukraine – and thus both material support for Kyiv and policies such as sanctions on Russia – has held. Indeed, it got substantially stronger in the wake of the February 2022 invasion.14

To the extent Russia is still wagering it can outlast Western resolve, it may yet win, but it could also lose. Much of Moscow’s strategy has been to wait to see first whether Trump, long a sceptic of U.S. support for Ukraine, would win the U.S. presidential election in November 2024 – and then how he will shape U.S. policy. Certainly, changes are afoot. But while Trump’s team has indicated that it will lean harder into negotiating an end to the war than its predecessor, the new administration’s view of an acceptable outcome will likely differ from Moscow’s – just as U.S. interests differ from Russia’s – and nothing yet hints that the White House plans to give up the leverage it enjoys before a deal is reached. Indeed, Trump’s late January social media comments point in the opposite direction, though inconsistencies in tone and content make it difficult to distinguish policy plans from off-the-cuff remarks.15

2.Ukraine, its backers and prospective peacemakers: In search of new miracles

In Ukraine, what felt akin to miracles in 2022 may have fed expectations of more wonders in the years that followed – and led to decisions that relied on a combination of wishful thinking and looking past grim realities. Ukraine’s leaders have increasingly berated its backers for not providing more weapons. They have requested weapons systems claiming that these would make all the difference, only to be disappointed when each new addition to the arsenal helped, but did not deliver victory. Meanwhile, the country has failed to mobilise and train an adequate fighting force. Though the Ukrainian army may have as many as a million people formally in its ranks, it has consistently lacked sufficient capable troops at the front.16 Kyiv consistently complains that its partners do not send enough or advanced enough weapons. But Ukrainian failure to build adequate fortifications in the war’s first year, and an August 2024 decision to divert troops to an incursion into Russia’s Kursk region, have likely enabled Russia to capture more territory than it otherwise would have.

Ukraine’s demand for NATO membership (discussed further below) likewise underlines an unwillingness to accept realities regarding its backers’ positions. Because joining NATO would enable Ukraine to invoke the alliance’s mutual defence commitment, it would either compel the Russians to go home or create the direct conflict that Western leaders remain set on avoiding. Washington and Berlin, among others, have remained consistently unwilling to accept that risk. Moreover, even if the White House did support bringing Ukraine into NATO, U.S. Senate ratification – which would be required – has never been realistic.

Other questionable narratives have also held sway at various times in the countries backing Ukraine. If at the start of full-scale war Russia’s victory seemed assured, its early failures led some of Kyiv’s friends to overestimate Russia’s vulnerability.17 Many of the expectations that Russia would run out of steam were (and to some extent still are) predicated on the belief that its transition to a partial war economy would be unsustainable.18 In the early days of full-scale war, Western officials were also sanguine about global support for Ukraine’s cause and confident that sanctions, if not decisive in themselves, would further sap Russia’s capacity to funnel money into its war machine.19

Russia shows little sign of impending failure.

Three years later, however, Russia shows little sign of impending failure. The impact of sanctions has been less than many hoped, in part because of smart fiscal management by Moscow. Incomplete and lax enforcement of sanctions – even by members of the coalition supporting Ukraine – has surely also played a role.20 But more important is that, even looking past Russia’s direct military support from Iran and North Korea, and the economic and other assistance it receives from China, many countries outside Europe, including those sympathetic to Ukraine, have chosen to hedge. They have kept up their ties with Moscow, rather than abide by a sanctions regime that could hurt them financially and which they had no role in defining.21 Russia’s economy, although far from booming, has therefore survived remarkably well.

Would-be peacemakers have also tended to nurture hopes or expectations that have not panned out. China, Brazil and India, as well as South Africa, have come forward to offer peace plans or urge talks. These initiatives have been rejected by Russia, Ukraine and Ukraine’s backers as unworkable or insufficiently concrete, and they are for the most part very broadly drawn.

Plans put forward by officials from outside Europe share several characteristics with those favoured by some in Trump’s circles, at least when he was a presidential candidate.22 A central contention is that the war can be ended through an agreement by which Russia stops attacking Ukraine and, in return, Kyiv gives up lost territory and its hope of NATO membership – that is, a “land for peace” deal.23

But “land for peace” proposals tend to see the war narrowly as a territorial dispute between Moscow and Kyiv, while Russia views it as a war in which it is taking on the entire West in a bid for its security. In Moscow’s view, dominating Ukraine is critical to its defence from a hostile, U.S.-led trans-Atlantic order. This view of the West also leads Russia to have ambitions that extend beyond Ukraine to revising the post-Cold War order in Europe. It thinks it must do so to increase its sway over the continent and weaken U.S. influence.24

The political deal that Russia does want – which would leave it controlling a swathe of Ukrainian territory while extracting a pledge of neutrality and the country’s demilitarisation – would be a step toward Moscow’s broader goals. But neither Ukraine nor any of its supporters seems likely to accept such a bargain.25 The former would correctly see it as a form of vassalisation, made more bitter by the hardships and atrocities Ukraine’s people have suffered during the Russian war of aggression. The latter would worry that an emboldened Russia will menace and seek to assert its influence over more countries, perhaps starting with Moldova, but maybe also trying its luck with others on NATO’s eastern flank. In short, because Russia’s fears and goals are broader than Ukraine, Ukraine-only solutions cannot bring stability.

III.Threat Perceptions: A Fearful Continent
Both accurate and misguided interpretations of the other side’s motives have affected the threat perceptions of Russia, Ukraine and Ukraine’s backers. But if Russia’s views have remained largely static, its full-scale invasion of Ukraine has shaken up most of the rest of Europe. As a result, today, most of the countries on the continent say they see their adversaries as posing an existential threat.

A.Russia’s View: The Threat from the West

Since at least the mid-1990s, Moscow has viewed Western policy worldwide as centred on weakening Russia and coercing it to act against its own interests. To be sure, there have been periods of more cooperation as well as less. Nonetheless, officials in Moscow have consistently decried the growth of the NATO alliance (even as Moscow worked with it through the NATO-Russia Council) and the EU to incorporate countries near and bordering Russia. Russian representatives have consistently contended that NATO enlargement is a threat to Russia, an argument made prominently by Putin himself when he addressed the 43rd Munich Security Conference in 2007.26

But these are not Russia’s only complaints about the West. Others include efforts to promote what Moscow characterises as decadent Western values in Russia’s neighbours and Russia itself. Russian leaders reject efforts to promote civil and political rights, including the rights of women and LGBTQIA+ people, as well as political dissidents. Moscow also condemns EU environmental and regulatory policies that affect trade with Russia and, not surprisingly, NATO and EU member state military activities. This litany of Russian frustrations is not the only factor complicating Moscow’s relationships with EU and NATO member states, but it has been central to the Kremlin’s narrative about the Western threat.27

Russia’s multifaceted sense of grievance is deeply rooted in what it sees as the loss of major-power status when the Soviet Union ... dissolved.

Russia’s multifaceted sense of grievance is deeply rooted in what it sees as the loss of major-power status when the Soviet Union (to which Russia believes itself the rightful successor) dissolved and a sense of vulnerability that flows from having a smaller economic and military capacity than the NATO alliance (and the U.S. alone). Moscow sees the trans-Atlantic countries and coalitions as threats because of the power imbalance. It has emphasised the importance of “regaining” its Soviet-era clout as a means of attaining security.28

Also reflecting the Soviet past, the Kremlin has come to believe that security requires domination of others, particularly neighbours.29 Indeed, Russia’s foreign policy discourse echoes not just that from the Soviet period, but also imperial Russia, leading some scholars to cite the country’s history and geography to explain Moscow’s perennial insecurity and desire to control more territory.30 At the same time, Russian nationalist ideologies tend to see neighbouring peoples as fair game for what is essentially colonial domination and Western rights rhetoric as intrinsically “foreign” to Russia. Meanwhile, scholars have observed that Moscow’s emphasis on the use of force evokes its embrace of a violent, dominant view of masculinity.31

Whatever the source, perceptions of threats from the West are today more integral to Russian policy than at any time since the Soviet Union’s dissolution. In March 2023, Moscow published a new “foreign policy concept” – a document akin to a national security strategy – predicated on the idea that the U.S., which it sees as the real decision-maker in the North Atlantic, wants to “destroy” Russia’s “territorial integrity”. The Kremlin pledges to counter Washington’s aims by undermining the U.S., including by damaging its alliances. NATO and the EU, according to this document, pose a danger to the “security, territorial integrity, sovereignty, traditional values and socio-economic development of Russia”.32

Such Russian formulations do not generally posit that a NATO military assault is imminent and, indeed, discussions of armed conflict with NATO almost always stress the inherent escalation risks, particularly that it could lead to nuclear war – though they sometimes proceed to explore how such a war might go.33 Rather, Moscow sees the alliance as a U.S.-led enterprise that looks to weaken Russia by a variety of means simultaneously. “Russia”, in this usage, refers not just to the country’s territory and government but also to a difficult-to-capture vision of Russianness informed by culture, social mores and ideology. These all have changed drastically over time, and, indeed, in the years since Russia launched its full-scale invasion of Ukraine. The position of Russian strategists appears to be that if the change stems from Kremlin decisions, it is appropriate. If it comes from outside, however, it is perilous. This stance, too, is consistent with the past: generations of Russian leaders have blamed foreign interference for domestic unrest they have seen as a threat to their power.34

Russian officials and analysts frame the war in Ukraine in terms that reflect these perspectives. A 2023 eleventh-grade Russian history textbook explains that Russia invaded Ukraine to prevent the latter from joining NATO. Had Kyiv become a member of the alliance, the textbook argues, it might have tried to retake territory in Crimea or the Russian-backed separatist-controlled parts of eastern Ukraine, which in turn might have led to wider war and “possibly the end of civilisation”.35A Russian analyst argued in the spring of 2024 (prior to the Ukrainian army’s sortie into Kursk) that Ukraine posed a threat to Russia because even small incursions from its territory could undermine Russian stability.36

A prominent Russian expert described the West as inherently dangerous to Russia.

Speaking to Crisis Group in late 2022, a prominent Russian expert described the West as inherently dangerous to Russia, arguing that Moscow has only its nuclear arsenal to deter its adversary. But the perils this expert described were not military. “Russia must keep the U.S. from interfering in domestic affairs”, he said, warning also of “attempts to pull Belarus to [the Western] side and strengthen Ukraine”. He could not explain how nuclear deterrence could prevent these things from happening. Nor could he say how it would stop anything other than direct military attack by NATO, which he agreed was unlikely, saying, “I’m not worried about U.S. missiles and the integration of Finland and Sweden into NATO”.37

At present, Moscow seems to expect the war in Ukraine to end in Russian victory. But nothing indicates that the Kremlin thinks victory will bring a peaceful future. Rather, Russian leaders seem to think, or at least find it useful to say, that the U.S. and its allies will continue to pose a threat comparable to the one they believe exists today. According to Russian experts, Trump’s election to the U.S. presidency has not yet changed this calculus, though the Kremlin may hope that the new president’s vision will align better with its interests. In the meantime, experts say, Moscow is not planning to adapt its approach.38

B.View from the West: A Menace Revealed
If Moscow’s threat perceptions and expectations of the war in Ukraine have stayed remarkably consistent, most of the countries backing Kyiv have shifted their views over the decades.

1.Before the all-out invasion
Prior to the full-scale invasion of Ukraine, the leaders of the three Baltic states and Poland disagreed fundamentally with most of their allies about Russia. The former had sounded alarms for decades that Russia would one day become aggressive. Estonian, Latvian, Lithuanian and Polish officials saw Russia’s 2008 war in Georgia, coupled with its 2014 annexation of Crimea and incitement of separatist rebellion in eastern Ukraine as proof of how dangerous Moscow was.39 Other Euro-Atlantic governments, including those of France, Germany and the U.S., however, judged Russia to be a hazard mostly to itself and to already unstable, non-NATO states near its borders – in short, dangerous, but at a low and manageable level. They saw the events of 2008 and 2014 as evidence of Moscow’s limited appetite and thought its destabilising actions in their own countries, such as spreading disinformation and undertaking covert operations, would be controllable.40

Thus, these countries engaged Moscow through diplomacy and trade even as they imposed various sanctions in response to Russian actions over the years.41 They talked to Moscow about global and regional issues, bilaterally and multilaterally, including through the NATO-Russia Council, established in 2002 to facilitate dialogue between the alliance and Moscow, which continued to meet until January 2022. Regional states, including Russia, participated in the Organization for Security and Cooperation in Europe (OSCE). The EU and NATO countries generally (or at least publicly) agreed that though the OSCE was often hamstrung by divides among members, its foundational premise, that it could enable cooperation in some areas despite substantial disagreements in others, held true.

Thus, until recently the West’s overall approach to Russia was rooted in the idea that the post-Cold War order was sustainable. To be sure, NATO bolstered its force posture, especially in the Baltic countries, starting in 2014, when Russia first invaded Ukraine, but as the accompanying statements illustrated, these steps were meant at least as much to reassure nervous allies, such as the Baltic states, as to deter Russia.42 In the same vein, NATO promised that if Russia attacked alliance members, it would risk a nuclear response.43 The EU, meanwhile, continued both to engage Russia and to develop ties with states neighbouring it, in some cases with an eye to eventually offering these countries membership, but mainly to foster prosperity, economic compatibility and democratic values as the appetite for enlargement dulled.44

2.After the all-out invasion
After the all-out invasion in February 2022, most NATO and EU countries thoroughly reassessed their longstanding assumptions about European security, with the majority agreeing that Moscow posed a threat too great to ignore. Importantly, the invasion led most European leaders to conclude that the Kremlin was not only aggressive, as its earlier incursions in Georgia (2008) and Ukraine (2014) had indicated, but also risk-tolerant. In contrast to 2008 and 2014, when the West did not throw substantial weight behind deterring Russian aggression, before the 2022 invasion Western leaders warned that Russia would face high costs if it proceeded. While Russia’s decision to attack Ukraine anyway did not necessarily mean that it would do something similar to a NATO member, it was an unwelcome signal. In Western eyes, it suggested an imperviousness to time-tested forms of deterrence and magnified fears of a Russian menace.45

Russia’s willingness to ignore warnings was not the only thing that jangled trans-Atlantic nerves. In December 2021, Moscow made proposals to NATO and the U.S., in response to their diplomatic outreach, seeking a commitment from the alliance not to deploy forces on its eastern members’ soil, which would have undermined these states’ defensive capacities.46 As Russian troops prepared to invade, Putin spoke ominously of “consequences … such as you have never seen in your entire history”, intimating that any state backing Kyiv might face Russian nuclear attack.47 Moreover, Moscow consistently slighted the agency of smaller European states, for instance by indicating that Washington could negotiate on behalf of all of NATO. Countries then outside the alliance, particularly Finland and Sweden, felt that Russia’s rhetoric and actions (including its aggression against Ukraine) meant it did not take small states such as themselves, or their sovereignty, seriously.48

Following the all-out invasion, most NATO and EU countries began adapting to what they now described as a concrete, insufficiently deterred and (as stated by many senior officials) existential threat to specific countries and to Europe as a whole from an aggressive, risk-tolerant, unpredictable Russia.49 Finland and Sweden both asked to join the alliance, after decades of avoiding this step, partly because they considered Moscow more dangerous than before and partly because they saw the limits of how much NATO would support a non-ally.50 The NATO member states nearest to Russia’s borders, meanwhile, believed they could no longer count on Moscow’s fear of war with NATO – and the associated threat of nuclear escalation – to fend off Russian aggression. They worried that they would suffer in the interim between a Russian attack and a NATO response, whether or not that response would eventually be adequate to recoup lost territory. Afterward, they called on the alliance to ensure that Moscow would expect any attack on them not only to have terrible repercussions but also to be doomed to failure.51

Against this backdrop, Western governments came to assess that a Russia made weaker by military failure in Ukraine would take this lesson more readily than one whose invasion had succeeded. Thus, when Russian victory did not come rapidly, and Russian soldiers were forced to retreat from large parts of Ukrainian territory in the spring of 2022, Western states saw an opportunity to help Ukraine while at the same time helping themselves by mitigating the longer-term threat from Russia. If Russia failed in Ukraine, perhaps its ambitions beyond Kyiv, or at least its capacity to attain them, might be tempered. In the best-case scenario, Ukraine would win, expelling Russian forces from its territory, and a chastened Moscow would rethink aggression.

A lengthy war in Ukraine carried terrible humanitarian costs and created its own security risks.

To be sure, a lengthy war in Ukraine carried terrible humanitarian costs and created its own security risks, including, in the worst case, of catastrophic escalation. Thus, support for Ukraine put its backers on a narrow path between what they saw as two threats – the one posed by Russian victory and the one that might lead to nuclear war. In the Baltic countries, Poland and (increasingly) France, officials seemed more focused on the first danger, which for them seemed the more immediate; they argued that, as Russia feared NATO, alliance members should ratchet up their support for Ukraine, in effect calling Moscow’s bluff.52 But Germany and the U.S., more worried about the second threat, advocated for gradual increases in assistance in order to limit escalation risks.53 The UK was mainly in the first camp, but it also made both arguments – that Russia presented “the most acute threat” to its security, on one hand, and that the peril of Russian nuclear use was “greater than at any time since the Cold War”.54

Importantly, for all their hopes of weakening Russia, the leaders of almost all NATO member countries, and of the alliance as a whole, do not appear to believe that the war in Ukraine, however it turns out, will in itself be enough to eliminate a long-term military threat from Russia. Nor do they seem confident that nuclear deterrence will be adequate to this task. While no official Crisis Group spoke with argued that a near-term invasion was plausible, many spoke of dangers down the road. In September 2023, a German official argued that even if Russian ground forces were greatly diminished, its navy and air force could do great harm to NATO assets.55 Western intelligence agencies say Moscow could have the capacity to mount a conventional military attack on a NATO member state, leading to potentially protracted war, in six years or less.56 Some officials contend that it could do so even sooner.57

Even after the all-out invasion, some NATO members stand apart from the rest of the alliance when it comes to threat perceptions. Hungary does not want to cut economic ties with Russia and downplays any risk, near or eventual, of Russian attack.58 Slovakia, once a staunch supporter of Ukraine, shifted to a more Hungary-adjacent position after Prime Minister Robert Fico came to power in October 2023.

Türkiye, in NATO but not the EU, also does not appear to view Russian aggression in Ukraine as an imminent threat to its own security, although it does see Moscow’s actions as dangerous to European stability. Officials say Ankara does not want Russia – with which it disagrees fundamentally on a range of issues – dominating the Black Sea; nor does it want the Kremlin tempted to venture further aggression in Europe.59 But Türkiye worries far more about internal actors, notably the Kurdistan Workers’ Party, or PKK, which it (along with the U.S. and EU) terms a terrorist organisation and has fought for four decades.60 Ankara has not aligned itself with the full package of Western sanctions against Moscow. While Turkish officials point to the weapons they have sent to Kyiv, they also say they want Russia to remain a counterweight to the U.S. Lastly, they stress their willingness to mediate in the conflict.61

Finally, the U.S., long NATO’s heavyweight and the source of most of the arms delivered to Kyiv to date, may be poised to shift its stance. If most of Washington’s European allies see an existential threat to their security, the U.S. has always had a bit more distance. As of now, President Trump has yet to clarify his position on the war, beyond saying he expects to attain peace, but it is clear that he sees weapons supplies as a source of leverage over Ukraine that he could wield in seeking to broker a settlement. He is looking to economic measures for leverage over Russia and may be inclined to look for opportunities to find other trade-offs, including in global politics, to reach a deal. But peace or no peace, there is every reason to think that the new administration will do what it can to refocus U.S. priorities on competition with China.62

IV.Fears into Actions?
Whether they preceded Russia’s full-scale invasion of Ukraine or are a product of it, the threat perceptions now held by Russia, on one hand, and the countries making up the trans-Atlantic coalition backing Ukraine, on the other, are now driving policy goals and narratives. Turning these into action is a different matter. As all these countries study how they must adapt their force postures and activities to match their fears and intentions, they are also grappling with the limitations imposed by budgets, politics, partnerships and other priorities.

A.Russia: Nuclear Deterrence, a War Economy and Force Expansion

Moscow has long been preparing for a standoff with Western states. Because Russia continues to rely on its nuclear weapons to cow its adversaries, it has sought to find a way to make its threats more credible, so it can force those adversaries to change their policies and behaviour. At the same time, Russia, which has substantially reordered its society and economy to sustain the war in Ukraine, is preparing to further enhance its conventional military might. In both of these realms, Moscow’s ability to attain its goals remains far from assured.

1.The nuclear card
Moscow makes no secret of its desire to see its nuclear weapons better intimidate its foes. It is frustrated that, thus far, all they have done is prevent direct conflict. Aside from rhetorical threats, Moscow has continued to use delivery vehicles that it can arm with either nuclear or conventional warheads to strike targets in Ukraine, a standing reminder of escalation risks.63 But this tool, like verbal warnings, risks losing its utility over time, particularly given the large number of Russian systems that are dual-capable.

In November 2024, Moscow published a new, amended nuclear doctrine. This text lowers the Kremlin’s stated threshold for nuclear use in an otherwise conventional scenario from a threat “to the very existence of the state [Russia or an ally]” to “critical threats to [Russia’s and Belarus’] sovereignty and/or territorial integrity”. The new doctrine also gives Moscow explicit permission to use nuclear weapons in a conflict with countries that do not have nuclear weapons capability but are aligned with others that do.64 The immediate threat is, of course, to Ukraine, but the broader warning is to all NATO and EU members.

Soon after publishing its new nuclear doctrine, Moscow struck Ukraine with a still-in-development intermediate-range ballistic missile called the Oreshnik. Like much of the Russian weaponry used in Ukraine, the Oreshnik is nuclear-capable. Unlike many of the other systems, it can also reach most (and perhaps all) potential targets in Europe. But while the launch could be taken as more nuclear posturing, Putin himself indicated the opposite, asserting that the Oreshnik’s deployment will bolster Russia’s conventional deterrence, lessening its need to make nuclear threats.65

Putin may well be having it both ways, brandishing the Oreshnik for its nuclear as well as conventional capabilities. While Moscow will likely continue to build nuclear weapons and to rely on nuclear coercion, it also has reason to expand its conventional capacity, so it can threaten adversaries with weapons they might be more likely to believe it will use. Russia has previously sought to build up its conventional deterrence into something more credible.66 But its resort to nuclear threats in 2022 and since then, as well as Putin’s comments about the Oreshnik, indicate that the Kremlin does not think its conventional deterrence is convincing enough. But the risk of escalation to nuclear use will likely remain at the core of any Russian conventional threat to its NATO adversaries. Were Moscow’s non-nuclear capabilities considerably more robust, it might indeed be able to make more believable threats. But even then, it is doubtful that the Kremlin would rely on conventional arms to do the work of deterrence (or compellence) on their own, especially against nuclear-armed adversaries.

2.Society, economy and military
Aside from the risks, building up military capability is expensive and potentially disruptive to society. But for Russia, the process is already well under way. Even before its full-scale invasion of Ukraine, the Kremlin had been actively militarising society, with more emphasis on military education in schools, facilitation of closer relations between the Russian Orthodox Church and the armed forces, and an uptick in militaristic government announcements, advertising and other messaging.67 The pace has only picked up since the full-scale invasion of Ukraine began. The Kremlin has portrayed militarisation to the population as necessary not just for the present war, but for the long-term standoff with the West – a narrative in line with past justifications of similar policies in Russia and elsewhere.68

The shift of Russia’s economy to a partial war footing also seems poised to continue. The state is now officially spending about a third of its budget on defence (the share had hovered at a bit over 10 per cent in the years prior to the full-scale invasion).69 Russia’s munitions factories are working around the clock, with several shifts of workers.70 This stepped-up production, along with high pay for soldiers willing to serve, has invigorated poorer towns where industry had long been closed down and employment opportunities were few and far between. With the help of high energy prices and trade with China and others, Russia’s economy grew in 2023 and 2024.71

To be sure, Russia’s economy also faces tremendous challenges: while the rising tide of war is lifting some boats, it has left others stranded. Western sanctions – despite not having the bite their backers hoped to see – still hurt. As of now, Russia’s economic growth is flattening, prices and interest rates are both up, and employers are struggling to find workers.72 The number of weapons being produced, meanwhile, is insufficient to meet Russia’s needs (Moscow is, after all, receiving substantial amounts of ammunition from North Korea, drones from Iran and electronic subcomponents from China). Further, Russian production relies heavily on refurbishing old weapons rather than building new ones, and Russia is running out of the former.73 But for all the hope among the Kremlin’s adversaries that Russia’s military-first approach will eventually prove unsustainable, the Kremlin for now seems to be making the opposite bet.

As for priorities, the overwhelming focus of Russia’s militarised economy, and a good deal of its weapon production and military preparation, seems to be on victory in Ukraine, rather than over-the-horizon planning for a future conventional war with NATO.74 While Moscow is surely also doing what it can to replenish stockpiles, it has pulled troops from near its borders with alliance member states in order to free them up to fight in Ukraine. This strategy has cost it. Both the rebellion by Yevgeny Prigozhin, the late Wagner Group commander, in the summer of 2023 and the Ukrainian army’s incursion into Russia’s Kursk region the next year demonstrated how little attention Moscow has paid to domestic security and defences. Indeed, Russia accepted Pyongyang’s offer to provide North Korean troops, who are now in Kursk helping Moscow in its efforts to expel the Ukrainians.75

Nor is Moscow able to do all it might once have hoped farther afield. Its military presence in Africa has continued to grow as the defence ministry takes control of the Wagner Group’s private empire, with new outposts in Burkina Faso and Niger. But Russia’s partners globally are surely aware of the limits of its power, particularly after it was unable to prevent its ally Assad from falling, leaving the future of its Syrian bases unclear.

The Kremlin has also boosted the authorised (that is, target) active-duty size of its armed forces three times since February 2022. The last increase, in September 2024, took that number from just over 1.3 million military personnel to 1.5 million, in part, officials said, to ensure the armed forces can counter the threat now presented by Finnish membership in NATO.76 While the true size of the Russian armed forces is classified, it is unlikely that the authorised number will be attained rapidly. Rather, the latest hike betrays the reality that the force has, in fact, been decimated by the war and new mobilisations are, if anything, just making up for the resulting gaps. Further, analysts believe Russia’s training pipeline remains geared to a force of about 1 million people, not more.77

To truly build a larger force, Moscow would have to undertake the massive mobilisation of personnel and resources that it has to date been loath to embark upon.

To truly build a larger force, Moscow would have to undertake the massive mobilisation of personnel and resources that it has to date been loath to embark upon, in part for fear that it would engender domestic unhappiness.78 Peace in Ukraine would help, in no small part because it would stem the loss rate and allow production capacity to refocus on the future. But with Moscow’s plans for a build-up expressed largely in numbers, what it intends for its military in the long run remains unknown, as does what exactly counterbalancing NATO means to the Kremlin.79

Articles in Russian military analytical journals paint a jumbled picture. They emphasise “hybrid” threats, many of which are not military, and the risks of escalation. Analysis that postulates a war with NATO presents it as involving a large-scale multi-domain attack on Russia, which Moscow can deter if it maintains adequate strategic nuclear capacity, perhaps arguing that adequate conventional capabilities would also be useful.80 Other analysts look directly at NATO actions and preparations to assess the dangers those pose, and to ask what Russia might need to do to counter them, from a deterrence or warfighting perspective.81 But as of now, the military literature, too, is silent about what Moscow plans for its future 1.5 million-person military.

B.The West: Supporting Ukraine and Bulking Up as the U.S. Retrenches

The challenge facing North Atlantic strategists since early 2022 has been one of balancing the effort to supply and back Ukraine with that of rejiggering national, NATO and EU capacity to better deter Russia – while at the same time avoiding escalation with Russia that could lead to nuclear use. While threat perceptions and policy lines for the most part converge, there are differences, and political shifts stand to make things harder. Perhaps the most significant such shift to date has occurred in the U.S., where Donald Trump’s election to the presidency creates uncertainty about Washington’s future role and complicates virtually every element of meeting this challenge.

1.Fortifying Ukraine
If Russia sees victory in Ukraine as the first stop on the road to its preferred security order, the West has seen thwarting this design as its first way station to sustainable defence. Arms deliveries and financial support to Kyiv have been at the heart of this effort, with the U.S. providing the bulk of the former for most of the conflict. NATO has sought to make military aid more sustainable by taking on coordination duties, but that arrangement does not guarantee either weapons or funding, both of which are now in question due to the change in U.S. administration. The new U.S. president and vice president have made comments indicating doubts about the value of continued military assistance to Kyiv – at least in the volumes sent to date.82

As gaps appear, the EU will continue to help its members buy more weapons for themselves and Ukraine, including likely from the U.S. Non-EU NATO members, such as the UK and Türkiye, will also continue to aid Ukraine even as they bolster their own arsenals. But while these countries are already doing a great deal, and EU military assistance now rivals that provided by the U.S., Kyiv’s other backers would still have a huge hole to fill if U.S. support shrinks.83 If Ukraine is to continue fighting, it will need a steady influx of weaponry and ammunition (even as Kyiv, itself, will have to be responsible for filling its ranks with personnel).84

In theory, there are other ways to deter Russian aggression in Ukraine. One request that Kyiv has consistently made – only to be rebuffed even before Trump took office – is for security guarantees. Many Ukrainian and European officials and analysts have advocated that NATO grant, or at least promise, membership to Ukraine immediately. Proponents of near-term membership believe that the threat of war with NATO implied in the alliance’s security commitments would force Russia to back down.85 But even beyond the political obstacles, opponents (who have included officials in the U.S., Germany, Hungary, Slovakia and Türkiye) argue that NATO membership for Ukraine could create the very direct war, with all its escalation risks, that alliance members have sought to avoid.86

Analysts and officials have proposed ways to resolve these challenges, such as by extending security guarantees only to government-controlled Ukraine, an idea termed the “West German model” (in that it echoes West Germany’s membership in NATO when the country was divided).87 Some Biden administration officials entertained the idea of extending a promise of membership – mainly as a political gesture – even though such a pledge already exists, first issued at NATO’s Bucharest summit in 2008 and reiterated at summits in Vilnius in 2023 and Washington in 2024.88 Others argue that any guarantees would have to wait until the war is over, given that all Ukraine is currently subject to Russian missile and drone attacks.89 But while such discussions may yet recur, the talk of prospective Ukrainian NATO membership seems to have died down toward the end of 2024. Indeed, Trump’s election may have silenced it for some time to come.

If not NATO membership, then could other useful guarantees be given?

If not NATO membership, then could other useful guarantees be given? Nineteen NATO member states, including the U.S., plus Japan and the EU, have signed bilateral security agreements with Ukraine, all promising continued military support for a decade. But although the agreements pledge this aid to keep Ukraine’s military capable and in some cases are even specific about types of weapon systems, they are not binding treaties, and even if they were, would only provide so much comfort about the volume and quality of assistance, much less any action in Ukraine’s defence.90

To the extent that NATO members do enter bilateral treaties or multilateral arrangements that offer binding security guarantees, these would raise the same problems as NATO membership. If a NATO member state is bound to join the war on Ukraine’s side, and is then attacked by Russia, other members would be obliged to assist it – or risk the alliance’s credibility and future. The same challenges would arise if no binding treaty is signed, but NATO allies send forces to help Ukraine. Whether they do so while it remains at war or after a tenuous peace that breaks down, should those forces find themselves fighting Russia, NATO could very well be drawn in, which, in turn, could lead Russia to strike NATO members and vice versa.

The same problems would come up should NATO member states deploy peacekeepers to the war zone once fighting ends. France and the UK have publicly discussed this possibility, whose logic is partly that these troops would serve as a tripwire, guaranteeing that if war restarts, the countries that sent forces, and their allies, would immediately be involved.91

Finally, the EU’s decision to grant candidate status to Ukraine, Moldova and Georgia also includes the promise of security guarantees, which are enshrined in the EU constitutive treaty.92 The decision marked a shift in the bloc’s more risk-averse approach to enlargement since the 2010s and was intended as a strategic signal of EU support for these three countries as well as opposition to Russia’s efforts to exert influence.93 (Georgia’s candidacy has since been frozen.94)

Because of the security guarantees, membership for a country at war or at risk of war is fraught, for all the reasons discussed above. Further, because of the overlap between NATO and EU members, bringing front-line states into the EU creates new possible mutual defence triggers for NATO as well.95 Moldova is defended as long as Ukraine controls its own south – Russia cannot reach the country by land (and the handful of Russian troops in breakaway Transnistria pose no real threat). But if Russia does attain access to Moldova, the latter’s minute military cannot put up much of a fight.96 Georgia also has limited capacity on its own.97 EU membership could thus be quite a commitment.

2.Building capacity
If Russia professes big plans about countering NATO in the long term, EU and European NATO member state schemes not only to support Ukraine over time but also to bolster their own capacities for weapon production, force generation and deployments have also proven more easily promised than carried out. The increased requirements of such plans coincide with a seemingly eroding U.S. commitment to their security coupled with pressure from the Trump administration to take responsibility for their own defence. To move forward, European countries will have to confront and somehow overcome the inconsistencies between their stated need to deter a large-scale war with Russia and the political challenges inherent in boosting spending and cooperation, as well as sustaining them into the future.

When it comes to spending, the trans-Atlantic bloc states have already done a lot. NATO member states have boosted defence budgets, many quite substantially.98 Twenty-three of NATO’s 32 members are on track to spend a minimum of 2 per cent of GDP on defence in 2024, as agreed at the alliance’s 2023 summit in Vilnius and some are far above this target (in Poland’s case, at over 4 per cent).99 For comparison, only three of the alliance’s then 28 members spent 2 per cent or more in 2014.100 But if the notable increase reflects a real change in threat perception, Trump has called on NATO members to ramp up their defence spending further, to 5 per cent of GDP – more than any alliance member, including the U.S., spends at present.101

Share of GDP is just one metric for progress, however, and it does not cover the waterfront. Neither proportional nor direct defence spending is an adequate measure of preparedness. Budgets can, after all, be spent well or poorly, depending on what is bought and how much is paid for it. Here, the challenges begin.

Europeans have long talked about strategic autonomy in the defence industrial sector.

On one hand, Europeans have long talked about strategic autonomy in the defence industrial sector and the need to be able to “act autonomously when and where necessary”.102 But Europe’s defence industries were not designed for rapid ramp-ups or for mass coordinated production at all. Individual states do their own procurement and purchasing. About half of what they buy, they buy from the U.S., although European firms take part in manufacturing U.S. weapons as well.103 European production, meanwhile, has been dominated by a handful of multinational companies. They and national firms put out a plethora of systems for their European customers, which are not as interoperable in reality as in theory. Ukraine has experienced the implications, as they have seen their European backers send them an eclectic arsenal akin, a senior Ukrainian official told Crisis Group, to what one might see in a video game.104

Since the start of full-scale war, the EU and its executive, the European Commission, have sought to make it easier to ramp up and sustain mass production and to coordinate standards and needs.105 To ease investment, Brussels has changed policies regarding how existing funds can be spent, aiming to help members free up money.106 The EU is also looking into creative ways to raise funds, including by borrowing, perhaps through defence bonds issued jointly by the EU and based on the precedent for common borrowing set during the COVID-19 pandemic.

Bloc members can also reach their goals by pursuing closer defence industrial between EU member states and European NATO members that are not in the EU, like the UK, Norway and Türkiye, and with other states, such as Switzerland or South Korea. To an extent, they are doing so already, albeit not without debate. These options require both overcoming buy-EU arguments and country-specific obstacles, such as the Republic of Cyprus (and sometimes other states) using EU member status and the bloc’s unanimity rules to block defence industrial cooperation with Ankara.

They are also looking to keep the U.S. engaged, partly by continuing to purchase its weapons and partly by convincing the Trump administration of the value of staying committed to Europe.107 The former seems, on the face of it, to be easier than the latter, as Trump has sought to champion U.S. business and U.S. weapons producers are important actors on the U.S. domestic stage. Moreover, given the current levels of European dependence on U.S. production, these countries cannot but continue to buy U.S. arms even as they build their own capacity and seek other partners.108 It seems plausible that U.S. firms will continue to sell as long as European countries are buying, especially given how interlinked U.S. and European defence industries are, meaning that any transition away from large-scale U.S. defence industrial engagement in Europe will almost certainly be gradual. That said, the U.S. defence industry has also struggled to meet the combined demands of Washington and its allies – if these strains mount, Europeans could lose out.

The politics of this balancing act will not be easy for European leaders. Historically, reliance on the U.S., and on NATO as Europe’s security coordinating mechanism, has shielded European countries from political challenges inherent in boosting defence spending and keeping it high over time, as well as coordinating security priorities among dozens of independent countries. But if the U.S. is less engaged, EU and NATO members must find a way to overcome both domestic dissent and their own disagreements. Even if leaders largely agree that the threat from Russia is real, European voters, regardless of whether they concur, may be more concerned with economic security and migration. They may bring to office new governments with different priorities, willing to take their countries along new strategic trajectories.

The consensus-based EU and NATO could thus find themselves hamstrung in efforts to move forward on their security agenda. In theory, member states could change voting rules to eliminate the need for unanimity on key decisions in the foreign policy and defence spheres, thus making it easier to act even if all do not agree. But such proposals have made little headway. Member states are loath to give up sovereign decision-making authority on such critical topics, and changes of this sort are likely to face steep political hurdles, not least because they would require unanimity in their own right.109 Another way forward is for countries to act in mini-lateral blocs with like-minded partners, using EU and NATO machinery where feasible and advantageous. This option has obvious advantages, but it could also prove divisive, particularly if it involves actions on which other member states fundamentally disagree.

3.Force posture
When it comes to force posture, planning, and command and control, how European countries think about their security has indeed shifted, now aiming to prepare, over time, for a large-scale conventional conflict. Further, NATO’s new regional defence plans and force deployments are meant to demonstrate to both Russia and alliance members NATO’s intent and capacity to defend each member state. The challenges may be greatest in the Baltic region, which is why those countries have been so concerned that NATO find a way forward. But the strategic shifts apply to other countries as well: a northern European official told Crisis Group in 2023 that past war plans had involved ceding territory early in case of Russian attack. These, he said, had been jettisoned, replaced by resolve to fight for every centimetre.110

The ramp-ups since February 2022 did not start from scratch, but they are more substantial than those undertaken previously. After 2008’s Russo-Georgian war, NATO increased its exercise tempo and began rotating four Enhanced Forward Presence (EFP) battalion-sized battle groups, drawing forces from various member states, through Estonia, Latvia, Lithuania and Poland. Since 2022, NATO has upgraded the Baltic Air Police missions and created four more EFP battle groups in the Black Sea region. All eight EFP battle groups are to be enlarged into brigades, although some are further along in that process than others.111

The alliance’s new force model is meant to get more troops to any prospective fight faster. If the NATO Response Force approach, in place since 2004, could rapidly put some 40,000 ground, air, naval and special operations personnel into theatre, the new approach, termed the New NATO Force Model, on paper at least draws on half a million troops. Of these, 200,000 are meant to be available within ten days.112 Due in 2024, the transition appears to be behind schedule.113

U.S. retrenchment poses dangers to the alliance.

Here, too, U.S. retrenchment poses dangers to the alliance. A lot of both NATO’s increased capacity and its previously existing capacity depends on the U.S. It is the U.S. that has established a new permanent garrison in Poland and signed defence cooperation agreements with the Nordic countries. It is Washington that has agreed with Berlin that Germany will host U.S. intermediate-range missiles starting in 2026, a type of weapon that had been banned by the U.S.-Russian Intermediate-Range Nuclear Forces Treaty, from which the U.S. withdrew in 2019.114 Within NATO, U.S. officers dominate command structures.

To be sure, the numbers of NATO member state troops, tanks and aircraft dwarf Russia’s even without U.S. forces included. These numbers grow even further if non-NATO EU members are added to the mix.115 But their capacity to act at present requires U.S. commanders, logistics, naval forces, air defences, uncrewed vehicles, specialised troops and systems, and ammunition, among other enabling capabilities.116 The numbers also mask the reality that some forces are simply better prepared and equipped than others, with Germany and the UK’s large force sizes belying significant gaps and, conversely, Finland’s small permanent numbers augmentable by a capable reserve and Poland’s rapid build-up.117 Thus, if the European allies expect the U.S. to pull some, if not all, of its troops out of Europe, they have a heavy lift ahead of them in ensuring that they will, in fact, be able to carry out their new plans.

4.The nuclear dimension
Then there is the nuclear dimension. Trans-Atlantic planning for a protracted and large-scale conventional war, just like Russian planning for such a war, requires officials either to dismiss the risk of nuclear escalation that has heretofore deterred such conflict or to somehow incorporate it. One way of incorporating it is to argue that deterrence is needed at a wide range of levels, including both conventional capabilities and diverse nuclear capabilities that could, according to this logic, more credibly deter adversary nuclear capabilities of various sorts.118 This thinking is not dissimilar from Russian hopes to develop more credible conventional weapons while also maintaining a large non-strategic nuclear arsenal and myriad dual-capable weapons, although Western planners seem somewhat more nuanced in their approach, speaking of deterrence “tailored” to specific adversaries.119

Such strategies are essentially escalation management strategies: they require one side to manage escalation effectively, such that the other side recognises the dangers and gives up. It fails, of course, if both sides, in their effort to manage escalation, instead continue to escalate. It succeeds if, indeed, the adversary backs down or, arguably, if for fear of just those dynamics, neither side acts.

A future in which both Russia and NATO members are trying to make threats more credible is not a secure one.

Given the challenges of escalation management, a future in which both Russia and NATO members are trying to make threats more credible is not a secure one. But this concern aside, a tailored deterrence strategy is probably impossible for European NATO members to pursue without the U.S. The U.S. nuclear arsenal is massively larger and more varied than that of the UK or France. The U.S. also provides the nuclear weapons now based in non-nuclear NATO member states as part of NATO’s nuclear sharing. When advocates call on the alliance to boost its nuclear capacity, it is mostly U.S. bombs they are discussing, although some are also entreating multiple allies to buy more delivery systems and France and the UK to up their nuclear contributions to the alliance.120

In terms of building the weapons, the U.S. seems committed. The Trump administration appears likely to embrace many of the ideas in the Project 2025 Mandate for Leadership, published in 2023 and intended as a blueprint for a future Republican administration. These include a substantial nuclear build-up with more and newer weapons, including the nuclear-armed sea-launched cruise missile program that the Biden administration first stalled and then greenlit.121

What is less clear is whether the U.S. will be thinking about deterring war in Europe as it follows this plan. Advocates of a build-up often argue that it is necessary to simultaneously deter Russia and China, and Project 2025 itself holds that the U.S. should withdraw conventional military support for its European allies but keep the nuclear umbrella in place. But President Trump has yet to announce his actual game plan. If the U.S. does pull back on this front, as well, European capitals will have to rethink their approach to the role of nuclear weapons in their plans for deterring Russia – and thus also for whether, when and how to fight a conventional war in the nuclear shadow.

V.Europe’s Emerging Order
A.An Unstable Dynamic
The fact that deterrence has held up to now indicates that the sort of large-scale conventional war for which the countries of Europe are preparing remains unlikely. For Russia to attack a NATO or EU member state, it would need to be confident that the alliance’s big powers will renege on their security commitments. In fact, Russia seems to take those commitments seriously – else it would not be so worried about the prospect of Ukrainian NATO membership. Nor does it seem plausible that NATO or EU members would directly attack Russia.

Yet neither Russia nor the NATO/EU states are likely to be talked out of their fears of the other or the impulse to build up their arsenals accordingly, and to worry that whatever they are doing is not enough, which brings its own risks. Western states, having seen the Kremlin embark on full-scale war in Ukraine at great cost, are disinclined to trust Moscow’s rationality or cost-benefit assessments to constrain it from future aggression. Russia, meanwhile, has defined its foreign policy around opposing a U.S.-led West, which Moscow sees as bent on doing it harm.

While enmity does not immediately translate into war, conflict risks rise when crises build up.

Russian and Western non-military activities also contribute to each side’s view of the other as hostile and dangerous. That includes Russian covert actions, including support of political parties, outright election interference, cyberattacks, disinformation campaigns, efforts to instrumentalise migration and apparent plots to bomb cargo aircraft and exploit undersea gas line and cable vulnerabilities, to say nothing of assassinations.122 For its part, Russia complains about Western critiques of Russian domestic policies and shelter for Russian (and Belarusian) dissidents. The two sides disparage each other’s leaders and take opposing positions on conflicts around the world. The resulting mutual distrust reinforces enmity and increases the tendency to see malice in every action.

While enmity does not immediately translate into war, conflict risks rise when crises build up. The most obvious scenario for clashes between NATO and Russia remains continued or recurring war in Ukraine, with higher escalation risks the next time around if the parties believe that earlier escalation last time might have led to better results. But those same perceptions can make disagreements elsewhere more dangerous as well, for instance if Moscow seeks to exert control of Moldova, with or without use of force. It is also possible that Moscow will test NATO wherewithal by increasing military activities near the alliance’s borders, which nearby states might view as a prelude to invasion. Conversely, Russia might misinterpret NATO exercises as the first steps in an attack.123 Political crisis raises the chances that concurrent military activities will be misinterpreted, while successive crises may make leaders favour a forceful (and escalatory) response.

If states think their adversaries are on the verge of attack, moreover, they may believe they must act pre-emptively, especially if they think there are military advantages to being on the attacking (“first mover”) side.124 In theory, parties could mitigate and deter such threats by building up defensively and ensuring the adversary knows they would respond forcefully. But it can be difficult to convince one’s adversary that one’s actions are, in fact, defensive. Since 2014, NATO and Russia have each said they were deterring and defending as they maintained a high tempo of exercises and operations in close proximity to the other’s territory – and thus to the other’s exercises and operations.125 Then, as now, each has viewed the military deployments of the other as dangerous and aggressive.126 Further, given that Russia did, in 2022, invade Ukraine after insisting it had no intention of doing so, it is understandable why its adversaries would doubt its words.

B.Encouraging Stability in an Unstable Order: Diplomacy and Deterrence

Even in an increasingly tense Europe, the parties have both reason and capacity to mitigate (though not eliminate) the risks inherent in the region’s growing militarisation. The pillars of this effort will be diplomacy, on one hand, and deterrence, on the other.

1.Diplomacy
A critical component of any effort to guide Europe toward a more stable future is settlement of the war in Ukraine. Beyond the drain the conflict creates on all parties, its immiseration of civilians caught in the crossfire and the risk of escalation it presents, the war’s continuation makes even a conversation about broader arrangements to calm regional risks all but impossible to begin.

Peace in Ukraine requires, first and foremost, that all parties back away from fantasy to face reality – including the reality of one another’s perceptions. While Moscow may believe that the best settlement of this conflict lies in Ukraine’s surrender and demilitarisation, followed by its acceptance of Russian dominance, it likely underestimates both the challenges of attaining the latter and the implications beyond Ukraine. Even if Kyiv loses decisively on the battlefield, Moscow would face a hostile Ukrainian population, which it or its Ukrainian proxies would struggle to control. Covertly or overtly, this population will almost surely receive aid and support from abroad, with European capitals nervous about the Kremlin’s next steps looking to make life harder for it. Tensions between Russia and Western states will heighten. Moreover, should Russia use its sway over Ukraine to put pressure on Moldova, yet another crisis would ensue.

In reality, no stable future is more likely if Ukraine does not emerge from the war able to defend itself. For Kyiv to retain this capacity, it would not need to regain all the territory it has lost prior to the end of fighting, although outside powers should go no further than acknowledging Moscow’s de facto control to avoid setting the precedent of accepting Russian claims de jure. Nor would Ukraine need membership in the NATO alliance, either for the country as a whole or for just the part controlled by Kyiv. Indeed, the fraught nature of security guarantees means that if these do emerge, it will likely be over time and as piecemeal, bilateral arrangements between Ukraine and specific partners.

Rather, unless and until a formula for security guarantees appears that is both politically palatable and does not create unacceptable escalation risk, it is critical that Kyiv retain a capable military. The Ukrainian armed forces need not only internal reforms, as Crisis Group has argued, but also continuing support on this front from its Western partners, who will also need to invest in Ukraine’s defence industry.127 Had Moscow known the extent of the resistance it would meet in Ukraine when it launched its full-scale invasion in 2022, it might well have been deterred. Such deterrence should be the aim going forward.

If peace talks commence, and Moscow goes in believing it holds all the cards, it will seek Ukraine’s demilitarisation, and through that its acquiescence and Russian access to Moldova. Kyiv, if it is at the negotiating table in part because it needs a peace deal to rebuild its military, will have limited capacity to object. But Moscow does not hold all the cards. Ukraine’s backers have a substantial amount of leverage over Moscow, because a possible conflict with them is what Russia fears. Of them, the U.S. has the most clout, because Moscow wants a bargain with Washington, in part because it believes the U.S. can deliver a security deal for the European region.128

Ideally, Ukraine’s backers would work together and with Kyiv to develop an approach to ... nudge Moscow to the negotiating table.

Ideally, Ukraine’s backers would work together and with Kyiv to develop an approach to first nudge Moscow to the negotiating table and then to maximise the chance that it accepts a sustainable deal. For both getting to talks and once they have begun, Washington can use Moscow’s worries about the potential that the U.S. will boost, rather than trim, its aid to Ukraine and heighten the economic strain on Moscow in the form of secondary sanctions, pressure on Russian trade logistics or an increase in the global oil supply to drive down prices. In consultation with allies, Washington can also capitalise on Russian hopes that sanctions might be eased to make sure negotiations are serious.

In embarking on talks with Moscow, negotiators should be prepared for tough and protracted bargaining. Their position will be strongest if they give nothing away up front. NATO membership and Western troop deployments are unlikely even if a peace deal is struck. But Moscow may not believe that, and Trump’s unpredictability means that nothing can be discounted in any case, there is no benefit from taking either possibility off the table before talks begin. Importantly, U.S. negotiators will want to ensure that any concessions on their part are available only in exchange for Russian climbdowns – and they should make clear that they cannot make concessions on behalf of other parties, who will not be bound to fulfil someone else’s deal unless prior discussions between Washington and other states have laid that groundwork.129 This could mean a wider negotiating table (although all parties at one table is neither likely nor desirable) or coordination as what will likely be multiple simultaneous discussions between various parties continue.

Once talks have begun, negotiators should look to states from outside the region for support. Brazil, China, India, Qatar, Saudi Arabia, NATO ally Türkiye and the United Arab Emirates have all expressed interest in being mediators. While medi-ation may not be needed, these and other countries can help facilitate a better out-come by expressing interest in European security in their bilateral conversations with all interested parties, including by increasing the pressure on Moscow to compromise. Of course, different states have different sorts of leverage, and their own priorities – but they do share an interest in a sustainable peace in Europe.

A settlement in Ukraine is inextricable from broader European security, but not enough in itself to mitigate risks. Talks about the latter should therefore kick off in parallel, though not everything has to be negotiated at once. The very fact of the broader talks commencing may help deliver a deal on Ukraine, as such dialogue offers opportunities to change Russia’s incentives. While the continuing war makes such talks impossible at present, that situation may change in the future.

The military dimension of European security is one that would benefit from early discussions, to lay the groundwork for a series of arrangements over time. Both Russia and the Western camp face economic and political constraints that ought to make agreed limitations plausible.130 While it is highly improbable that a broad new treaty on large-scale conventional forces in Europe can be hammered out, smaller deals with Russia, affecting handfuls of NATO member and other countries, might be, though participants would need to carefully coordinate with allies and partners as they negotiate.

These, combined, could be the beginnings of a new approach to security in Europe – one that is more schematic and arrived at through negotiation with a view toward risk and cost reduction rather than something that emerges from assumptions, perceptions and reactive decision-making. Many may take the form of reversible mutual or unilateral commitments, which will have the advantage of built-in snap-back mechanisms if adversaries do not keep their side of the deal. For example, if Russia deploys troops somewhere it had said it would avoid, trans-Atlantic countries can walk back one of their own self-imposed constraints and/or reimpose sanctions that had previously been eased.

If such discussions begin even as negotiations over Ukraine continue, they may strengthen the prospects for peace in Ukraine. Such an approach can apply to specific deployments and exercise schedules and even, in some cases, to the development of categories of weapons, and commitments can be directly tied to Ukraine. For instance, Washington and Berlin are discussing stationing U.S. intermediate-range weapons to Germany. Deployments can be put on hold while Ukraine negotiations are proceeding to keep Russia at the table. They could also be traded away later for agreed limits on Russian deployments of certain systems, for example its dual-capable systems and/or intermediate-range capabilities including (in both cases) its new Oreshnik missile.

Agreed limitations on aid to Ukraine could be packaged with limits on weapons deployed or activities in certain European zones more generally.

Similarly, agreed limitations on aid to Ukraine could be packaged with limits on weapons deployed or activities in certain European zones more generally, such as the Black Sea and Baltic Sea regions, with concomitant constraints on Russia to ensure that European countries feel more secure. Such agreements could also address how to manage third-party traffic in the relevant waters. Hotlines and military-military channels will also be critical to any path forward, especially for limiting escalation risks in a crisis.

The questions of domestic interference, covert actions and so forth are less amenable to such arrangements because they are so open to denial and interpretation. But some specific promises might be possible, and once the parties are talking, these are the conversations they may want to have.

Finally, easing of certain sanctions (excluding those that directly hamper the Russian war effort) in exchange for Russian fulfilment of key commitments, to Ukraine and to other states, is also worth exploring. Here, it is important to differentiate between sanctions that limit the Kremlin’s capacity to invest in its military might, notably weapons production, dual-use technologies and military industry, and sanctions that were meant to signal discontent and punish Russian officials, such as visa bans. Some, notably the sanctions on Russia’s economy as a whole, fall somewhere in between. The first category of penalties should remain in place as long as Moscow poses a threat to other European countries, which is likely to be a long time. The second set can be relaxed, at least for some officials, once talks begin or early agreements are made. The third would require substantial progress. The threat of new sanctions should hang over talks until a deal is signed – and remain potential punishment for violations.

Of course, talks could fail. If they do, conflict could well continue until the parties are ready for a deal, with ever-increasing uncertainty and risk for all parties. For instance, should President Trump, having decided that Moscow has flummoxed his plans, deliver massive amounts of new military aid to Ukraine, as some of his advisers have suggested might happen, Moscow would face tough decisions.

2.Deterrence
Whether or not diplomacy yields deals will shape how expensive and unstable the future will be. But there is no way to escape the reality of substantial instability and cost in most likely scenarios. For the EU and NATO member states, there is no way forward that avoids a big measure of deterrence. That in turn means tough decisions and the assumption of risk, especially with a less involved U.S. If European members of NATO and the EU do not stand up for Ukraine and each other, Moscow will likely be able to press them for further concessions, with huge economic as well as security costs. Moscow may try this gambit regardless of whether it prevails in Ukraine, of course, but a record of failures could, over time, start to become dissuasive.

The question of how to stand up for Ukraine starts with the question of how far, and how, the Western deterrence umbrella extends. The war in Ukraine since 2014, like that in Georgia in 2008, illustrated the reality that states outside that umbrella’s coverage are unprotected from Russian designs. Extending the umbrella further might deter Russia. But it would also increase the risk of nuclear war, for all the reasons noted above.

The existing blocs and their members thus face tough decisions about what commitments they can make and keep. With NATO expansion unlikely, there may be an inclination to place greater emphasis on possible EU accession, even though it presents some of the same knotty issues. In any case, the promise of EU membership inherent in candidacy status for Ukraine and Moldova (and Georgia if the current hold on accession ends) is conditional on reforms and unlikely to move quickly. Thus, for now, the strongest commitment already granted to Ukraine is continued and substantial military assistance and coordination, which for all its imperfections has a track record.

Should there be a settlement, Ukraine’s European backers float the idea of deploying troops as peacekeepers, though it is presently difficult to see how such a mission would work, given the escalation risks and Moscow’s opposition. It would additionally be challenging for anything but a very large peacekeeping contingent to cover such a huge swathe of territory, including Ukraine’s borders with Belarus and Russia as well as the lines where Ukrainian and Russian forces lay down their arms.131 Trainers may be more plausible, despite also posing some of the same risks.

If NATO weakens as a result of a less engaged U.S., security commitments by smaller coalitions of countries become more likely.

If NATO weakens as a result of a less engaged U.S., security commitments by smaller coalitions of countries become more likely. While it is hard at the moment to imagine a coalition of Baltic and Nordic states extending security commitments to Ukraine (or Moldova or Georgia) without the rest of NATO’s backing, it may be easier to envision a future where they are less confident of NATO already, and have built up their own forces substantially. Coalitions that also include France and/or the UK would add nuclear deterrence capacity to that side of the equation, as well, though they might also increase nuclear risks. Such deals would be a recipe for instability: they risk weakening the alliance further, raising questions not just about what commitments it will keep, but also about what it is, in fact, committed to. Still, in a deteriorating security environment, states may decide they are better than nothing.

In part to mitigate the risk of just such a future, the European countries that are backing Kyiv need to find ways to develop the military capacity they need independent of U.S. leadership, engagement and enabling capacity, even as they continue to involve the U.S. as much as possible, including in the mission of supporting and supplying Ukraine. They should improve their own capacity for lift, reconnaissance and command roles, among other enablers that the U.S. now brings to the table.

They will also need to expand their defence industry cooperation, not just with the U.S., but with non-EU NATO member partners like the UK, Norway and Türkiye and maybe other partners like South Korea. They can do so in smaller coalitions, which also may help mitigate challenges presented by, for example, Türkiye’s relations with the Republic of Cyprus, which is one of several obstacles to extensive military industrial cooperation between the EU and Ankara.132 Turkish involvement not only brings substantial capacity to the project, but it also helps cement Ankara’s position as a critical European security partner.133

For the EU to become fit for purpose as a geostrategic actor in its own right, it may well need to adapt its voting system to make decisions on defence and foreign policy easier.134 For now, and likely for some time to come, however, that is probably a bridge too far. Smaller coalitions can, of course, get things done, but they would render the EU a facilitator rather than an actor in its own right. If politicians sceptical of current policies come to power, however, that may be how the bloc evolves. For now, however, the EU as an institution is crucial to strengthening economic measures intended to blunt the effects of Russian military renewal (which, after all, would target EU members) and to enable its members to coordinate policies and positions. It may not be perfect, but it is, for now at least, essential to the project of European security.

The actions needed to raise the cost to Russia of further aggression are pricey, politically difficult and not guaranteed to succeed. They also carry their own inherent dangers. Not least of them is that deterrence may fail, and the resulting escalation will be even more catastrophic. But there is no way to mitigate risk without accepting some measure of it. If deterrence has a good track record of keeping Moscow and the West from coming directly to blows, it will be more effective still if coupled with better analysis of assumptions and threat perceptions on both sides, and complemented by serious, inventive diplomacy to mitigate costs and risks.

VI.Conclusion
There is no perfect solution to Europe’s security dilemmas. But the most durable way forward starts with an end to war that ensures that Ukraine remains sovereign and able to defend itself, and Russia is wary of the costs of renewed aggression. These outcomes are both more likely and more sustainable if the trans-Atlantic European countries are increasingly self-reliant, while the U.S. also remains engaged, even if at a lower level. This future, in turn, will be more attainable, and more enduring, if all parties begin to at least discuss how they can cooperate to mitigate risks on an increasingly militarised continent.

Kyiv/London/Washington/Brussels, 1 February 2025