The transatlantic relationship is undergoing a tectonic shift. The current US administration has made it clear: European states must take responsibility for their own security and deter the threat from Russia, while the US shifts its strategic focus to the Indo-Pacific. This rebalancing leaves Europe at the crossroads. What does it mean for the European security architecture, and what could be Ukraine’s role in this new reality?
Recent months have exposed growing cracks in transatlantic unity. From US Vice President JD Vance bashing European allies in Munich to tense exchanges in the Oval Office, culminating in the infamous meeting between US President Trump and Ukrainian President Zelenskyy. From the US launching tariff wars against its allies to openly floating the idea of taking over Greenland and Canada.
Changing Transatlantic Reality
These divisions are also evident in the diverging approaches towards Ukraine and peace efforts. The US is no longer calling Russia an aggressor, contemplates the reset of the relations with Moscow, and even echoes Russian narratives. On 24 February 2025, while European leaders gathered in Kyiv to mark the third anniversary of Russia’s full-scale invasion—reaffirming solidarity with the Ukrainian people—the US voted against the UN General Assembly resolution condemning Russian aggression against Ukraine. In doing so, it aligned itself with Russia, Belarus, North Korea, and a dozen dictatorships, like Mali or Sudan.
The Trump administration has presented its efforts as aimed at ending the “bloody war,” but its primary objective seems to be brokering “a deal,” regardless of its content or implications. In contrast, for the Europeans—in addition to Ukrainians—the terms of the deal matter, prioritising a sustainable solution over a quick fix.
Moreover, the US has exercised disproportionate pressure on Ukraine, including temporarily withholding support, pushing for a so-called “critical minerals deal,” which raises concerns about economic coercion, and threatening to withdraw from the negotiation process altogether. Meanwhile, no comparable pressure has been applied to Russia—suggesting perhaps a lack of real leverage—even though it has refused to accept the terms of the ceasefire, continuously escalated its demands and intensified its attacks on Ukraine, including brutal strikes on residential areas and civilian infrastructure.
The American position vis-à-vis European Allies is clear—Europe needs to do more for its own defence. The US suggested a new benchmark of 5% of GDP for defence expenditures at the recent NATO Defence Ministerial meeting, while itself being far from the target. This is not only about burden-sharing, but also burden-shifting within the Alliance. The US appears increasingly disinterested in contributing to European security, and instead is pivoting its strategic focus towards what it perceives as its primary threat: China. The debate is ongoing regarding the US pulling out its troops from Europe and reassessing its role in NATO commanding structures, but the US is on a clear trajectory of disengaging from Europe. While NATO makes every effort to keep the Americans in, it is clear that the nature of this engagement has fundamentally changed.
Who Will Defend Europe?
As the EU and its members seek to reduce their dependencies on the US and increase defence autonomy, a number of steps have been taken—from the historic decision of the Bundestag, to the ReArm Europe/Readiness 2030 plan. Crucially, the emerging European security architecture must fully encompass Ukraine—not at some undefined point in future when it becomes an EU and NATO member, but now.
It is time to stop viewing Ukraine as a “buffer”—an outer shield protecting Europe and buying it time to re-arm, grow capabilities, and prepare. Even by mere geographic terms—not to mention the shared freedoms and values—our security is deeply intertwined. This is a European war, and Ukraine is your eastern flank.
If Europe fails to act decisively now, and Ukraine is either defeated or forced into an unfavourable “peace,” who is next? Will any European state be able to sustain a high-level intensity war with Russia, with daily bombing and civilian casualties? Who from your allies will come to your support? Will Russia’s highly militarised economy suddenly stop, once it considers the “Ukraine issue” as “solved”? Will hundreds of thousands of Russian soldiers, who now earn $3.5k per month, simply return to their depressed regions with an average salary of $100-200 at best?
In the new reality—especially as the US gradually disengages—Ukraine is not a liability but a key security asset for Europe. The Ukrainian military is not only a security guarantee for Ukraine but also for Europe. We need to join forces to help each other realise our full potential and successfully deter Russia.
Europe’s Most Potent Military Force
Ukraine has the largest battle-tested army in Europe with unmatched, up-to-date experience in countering Russian conventional and hybrid warfare. It is in Europe’s own strategic interest that this force becomes part of the continent’s deterrence architecture—rather than, in case of Ukrainian collapse, being imprisoned, executed, or forced to fight on the Russian side, as it already does with Ukrainians from the occupied territories.
Ukraine is growing its own defence capabilities, like long-range missiles, drones, and artillery rounds. While in 2022 Ukraine relied heavily on western support, right now the share of its own production exceeds 40%. Moreover, these solutions are not theoretical but tested in real war conditions—something many partners are missing. Still, Ukrainian production capacities exceed what its defence budget can purchase. That is why the solution of supporting Ukraine through direct purchases of its own weaponry—known as the “Danish model,” as Denmark was the first to implement such an approach—has proven successful and should scale up.
Ukraine leads in military innovation, especially in unmanned systems and electronic countermeasures. Ukraine has successfully developed and used maritime drones, like Sea Baby and Magura, which contributed to a number of successful operations in the Black Sea and Crimea. Its Neptune cruise missile, which sank the flagship of the Russian Black Sea Fleet (the Moskva cruiser), has been successfully tested in its long-range modification. The so-called Long Neptune was used to hit the oil refinery in Tuapse at a distance of about 1 000 km. Ukrainian drone innovations helped achieve the distances of 1 700 km for the deep strikes into Russian territory.
Understanding the importance of drones in modern warfare, Ukraine was the first to establish a dedicated Unmanned Systems Forces as a separate branch of the Armed Forces. Another key battlefield innovation from Ukraine is its DELTA management platform, which was repeatedly recognised by NATO experts.
Ukraine also holds invaluable intelligence on Russian military tactics, operations and strategic thinking, as well as insights into its growing ties with other authoritarian powers, like Iran, North Korea, and China.
Beyond the battlefield, Ukraine has shown exceptional societal resilience. As European intelligence agencies increasingly warn of the growing direct threat from Russia, the importance of the whole-of-society approach to defence becomes more acute. Ukraine did not collapse in days or weeks—it demonstrated institutional adaptability and remained largely democratic, despite limitations of the martial law.
It also showed some remarkable energy sector resilience, despite severe damage to energy infrastructure inflicted by continuous Russian attacks. For some countries, it would take longer to recover from a weather storm than for Ukraine to recover after a heavy ballistic strike on a substation. Even amidst the war, Ukraine advanced key reforms and accelerated its European integration track. Ukrainian society remained mobilised and united in stepping in to provide support to the state and the defence forces.
What European Partners Should Do Now
Europe needs to step up the military and financial support to Ukraine. North Korea alone has reportedly sent Russia 15 800 containers of munitions—equivalent to 4.2-5.8 million shells. At the same time, EU foreign policy chief Kaja Kallas struggles with her recent plan to obtain 2 million munition shells for Ukraine from the EU.
Air defence remains critical, especially as Russian strikes on Ukrainian cities and towns intensified. The US administration is neither preparing new support packages nor considering Patriot systems sales to Ukraine. European partners with Ukraine must urgently develop a viable solution.
Our partners should also consider ensuring the sky shield—an integrated air defence zone that employs combat air patrols over western and central Ukraine, including Kyiv and Odesa. The involved aircraft will fly from the European bases and coordinate closely with the Ukrainian Armed Forces to protect the country’s airspace. This would allow Ukraine to relocate its assets eastward, enhancing the protection of big cities and limiting Russia’s ability to deploy the glide bombs against both frontline troops and civilians close to the Russian border.
Sky shield can become not only part of the strategy for immediate support of Ukraine’s defence but also a longer-term solution to ensure post-war recovery and reintegration, as well as economic and industrial development.
Another important step would be the presence of the European troops on Ukrainian territory, as part of the “reassurance force,” potentially providing land, air, and maritime support, safeguarding critical energy infrastructure, like nuclear power plants, and helping with training and capacity-building. It is important to remember that while the scope and mandate of the forces would be broader this time, the precedent is already there.
As a response to the beginning of the Russian aggression in 2014, several military training missions were launched in Ukraine in 2015 to increase its capacity to defend itself: Joint Multinational Training Group-Ukraine, led by the US, and comprising contributions from 8 countries; UK-led Operation Orbital; and Canadian Operation UNIFIER. They successfully operated until early 2022, before being suspended and evacuated amidst Russian military build-up, partly because the Allies assessed Ukraine would not hold against a much bigger and powerful enemy. That assumption has proven false, yet the training missions are no longer present on the Ukrainian soil but have been readjusted to train Ukrainian soldiers abroad.
It is important that the new mission has a robust mandate, scope, and means. It can not be hastily withdrawn if Russia decides to escalate again, but instead must be equipped to respond appropriately.
Finally, the sanctions against the Russian Federation should not only remain in place, but they must be strengthened. Russia has shown no intention to cease its hostilities. European partners should also find the political will to seize the Russian frozen assets and use them for Ukraine’s recovery and immediate defence needs. If not a full seizure, maximising the profits through more efficient instruments should be considered. After all, the frozen assets remain one of the key tools primarily in the hands of European states, with the majority of the funds located in Belgium. The money can potentially fund Ukraine’s and Europe’s defence efforts. Needless to remind that there is a risk of it going back to Russia and funding its war machine against Ukraine and beyond. The defining moment comes already in July with the sanctions prolongation, and it will demonstrate if the European Union is able to overcome Hungary’s obstruction.
European defence begins with Ukraine’s defence. It is in Europe’s best interest to stop Russia with and in Ukraine, before it is forced to counter Russia within the EU or NATO.
This article was written for the Lennart Meri Conference special issue of ICDS Diplomaatia magazine. Views expressed in ICDS publications are those of the author(s).