The conflict in Ukraine is at a tipping point. US president-elect Donald Trump plans to settle the war “in 24 hours”, but he doesn’t have a clear plan, and success hinges on both sides being ready to compromise – unlikely at this stage. Ukraine’s stance on the war’s outcome has shifted, now prioritising diplomacy as a way to end the war.  However, this would require the resources to achieve significant military successes or, at a minimum, hold out on the battlefield. The Kremlin, for its part, is still striving for full and complete victory. It aims to seize even more Ukrainian territory than it currently controls while feigning openness to negotiations that hinge on Ukraine’s abandonment of its sovereignty and recognition of Russia’s annexations.

EU member states appear paralysed at the prospect of a rushed peace negotiation over Ukraine and an end of US military assistance. Since the invasion, they pledged to support Kyiv for “as long as it takes” because it felt like the right thing to do, not because they had considered the strategic implications. Now some Europeans may be shifting from one ethical stance (“defending a European democracy against a brutal autocratic aggressor”) to another (“promoting peace”), again with little consideration for their own strategic interests.  This risks leaving Europeans absent from talks that will shape the future of their security. Although it may feel ethical to let the Ukrainians define the terms of negotiation, the outcome may clash with the EU’s broader security interests.

Despite remarkable unity since 2022, Europeans are fast becoming divided over Ukraine. Some primarily in northern and eastern Europe insist that Ukraine’s fate is “existential”, while others could be willing to compromise for a cessation of hostilities. As early as the spring of 2024, ECFR polling identified that such debates over Ukraine’s fate also exist among European publics. It is therefore crucial to recognise these differences and strive to maintain a cohesive approach as the conflict enters a new phase.

Ukrainians are fighting a war on their own soil, defending their very existence. They should hold the power to determine the timing and conditions of ceasefire negotiations with Russia. However, it is important for other Europeans to recognise that they, too, have their own interests and can play a role in achieving the best possible outcome. This outcome should ensure the safety and stability of not only Ukraine but also Europe as a whole.

There are three fundamental and interconnected questions that Europeans need to answer, preferably jointly:

1. What are the key European security interests in a post-Ukraine war Europe?

Whatever the outcome in Ukraine, Russia will most likely remain a challenge for European security over the years to come, and the pillars of the post-cold war European security architecture will not be restored. Russia will continue posing a direct or indirect threat to Europe in multiple areas, from the Arctic and Europe’s “high north” to the Baltic region and the Black Sea. It will continue to exercise pressure in the post-Soviet space from Belarus to Moldova and from Ukraine to the south Caucasus. Its hybrid tactics below the threshold of major conflict, including cyber-attacks, targeting undersea infrastructure, intelligence operations, and election interference, will continue and potentially expand.

Moreover, senior military figures assess that Russia will have reconstituted its land forces and conventional offensive capabilities within five to seven years. A Russia that holds a portion of Ukrainian territory and has successfully pushed Belarus out of its neutrality to host Russian troops and nuclear missiles will be more threatening than at any point since the end of the cold war. In the meantime, the traditional tools for cooperatively managing European security have faded away. The Organisation for Security and Cooperation in Europe and its toolbox for confidence-building and conflict resolution have become dysfunctional, while the entire series of arms control treaties, including the Intermediate Nuclear Forces Treaty and Conventional Forces in Europe Treaty, have been violated and dismantled.

In such an unfavourable environment, Europeans have to identify these threats precisely and find ways to deal with them, which may include military responses as well as mutually agreed upon deconfliction or transparency mechanisms. Negotiating these arrangements will only be possible if Russia has an interest in doing so. This means that Moscow must acknowledge that Europeans have a stake in these issues and that failing to establish these arrangements could impact Russia’s own security. Europeans, therefore, need to create security dilemmas for Russia that could force Moscow back to the negotiating table. This entails building defence capabilities but also leveraging other tools of power and influence where appropriate.

2. How can a peace settlement guarantee Ukraine’s lasting security, stability, and ability to defend itself?

This discussion comes down to the kind of security guarantees needed to establish a lasting peace that aligns with European interests in Ukraine. There are several complex aspects to consider here. One is ensuring that any future settlement is accepted by the Ukrainian public and does not result in domestic instability. Another is providing enough safety for Ukrainian refugees to return and help rebuild their country while preventing further emigration after martial law is lifted. Lastly, Kyiv will need to attract investment to rebuild the country and enhance its military and industrial capacities to develop its economy and manufacture most of what it needs to defend itself.

Ultimately, the main question is what kind of security guarantees Ukraine’s partners can offer beyond the bilateral security agreements signed after the 2023 NATO summit in Vilnius. Only solid and credible security guarantees can ensure that Russia doesn’t start a new war a few years from now and incentivise Ukrainians to stay and rebuild their country. The alternative – a country drained by years of war and massive emigration – would be a major challenge for the EU. It is not in the bloc’s interest to have Ukraine as a semi-failed state in a security vacuum or as a new Belarus, an authoritarian and corrupted Russian satellite.

Three proposed models could provide sufficient reassurance for Kyiv, either separately or in combination:

• The ‘porcupine’ model: This involves arming Ukraine to the teeth for the foreseeable future to enable it to counter any new Russian aggression successfully. This model would be costly and might not be politically sustainable given the debates surrounding European and US assistance to Ukraine.
• The ‘Korean model’: Based on the post-armistice situation in the Korean peninsula, this model implies an enduring presence of Western troops in Ukraine to prevent a resumption of the conflict. Such a presence would need to be robust to effectively deter. It would be demanding and costly, especially for Europeans, if they were to shoulder most of the load. The command structure for such a presence (NATO, EU, ad-hoc) would also be a sensitive point with Washington.
• The ‘West German model’: In this scenario, Ukraine would enter NATO, even if it did not control its entire territory. This would be the most powerful and efficient signal from a military perspective, as it would provide Kyiv with the most solid security assurance. It would also firmly anchor Ukraine into NATO’s defence and deterrence posture, integrating it into its planning structure. Despite significant differences, the admittance of the Federal Republic of Germany into NATO in 1955 offers an interesting precedent. West Germany joined NATO without recognising East Germany or the post-war borders of Germany while facing constraints on its military posture and excluding West Berlin from Article 5 coverage.

Each model has specific costs and requires varying levels of commitment from Ukraine’s partners – specifically, its European partners, who will have to bear the bulk of the effort involved in each model. Europe needs to clarify which mix of the three approaches it favours, and which one would best serve its long-term security interests. Many European governments have already signalled support for NATO membership, but it is a controversial issue as some NATO allies are fiercely opposed while others are cautious or even hostile to a NATO enlargement. However, the alternative – providing solid guarantees of military assistance in the event of a resumption of the conflict – may prove suboptimal.

3. How can European leaders make sure that Ukraine will be in a good negotiating position?

Answering the first two questions (securing a safe and stable Ukraine and ensuring European security interests over the long term) will only be possible if Ukraine is in a favourable position when talks begin. Therefore, in the coming months, Europeans should strive to help Ukraine improve its position on the battlefield, which will define Kyiv’s bargaining power when negotiations start, possibly as early as 2025. The aid given to Ukraine now should be seen as an investment in the security of Europe’s future.

Today, the Kremlin seems to think it can prevail on the battlefield and will not negotiate anything short of an unconditional surrender. Putin’s demands are extreme, making any negotiation extremely complicated. The European role is, therefore, to alter this calculus to convince Moscow that its maximalist war aims are not attainable. This requires a powerful message of support combining political backing with economic and military assistance, even without a parallel effort from Washington. This is also what will determine the EU’s importance to other stakeholders, most importantly Russia, the United States, and Ukraine, and what will empower Europeans in future negotiations.

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These are not easy questions, and they may trigger a difficult conversation among Europeans. But this discussion is more necessary than ever, as the public in some European member states is starting to question the necessity of assistance to Ukraine, and some political forces are pushing a defeatist narrative about peace. To truly achieve peace, Europeans must redefine their strategic interests beyond simply ending war and focus on strengthening collective security for the long term.

Moving from the ethical narrative to a strategic one will bolster the argument for continuing to support Ukraine, paving the way for a just and sustainable peace. European governments and institutions must accept that there’s no returning to business as usual with Russia. The future relationship will be, at best, marked by distrust and competition, and might well involve enduring tensions and direct or indirect confrontation. A Russia that emerges victorious over Ukraine would usher in an unpredictable era of strategic instability in Europe.