From ongoing war to stable truce

In early 2025, triggered by the Trump administration's push for a peace deal in Ukraine, France and the United Kingdom initiated discussions on security guarantees for Ukraine in a so-called Coalition of the Willing. For Europe, this was a way to show Trump that Europeans were serious about putting more "skin in the game", in the hope of becoming part of the negotiations. The key question in these discussions was how a future ceasefire between Russia and Ukraine could be constructed in such a way that Russia would be deterred from attacking Ukraine again in a few years. How can the mistakes of the past be avoided in the future?

In many ways, the discussion was a useful exercise in that it spelled out in detail some preconditions for a stable future peace. The international talks on security guarantees led civilian and military officials in Western capitals for the first time to imagine and seriously plan for their countries' future engagement with, around and in Ukraine. At the same time, however, these discussions suffered – and continue to suffer – from four defects.

First, the discussions and negotiations on security guarantees for Ukraine have – at least so far – contributed little to ending the war. Various concrete proposals made on Ukraine's future security, such as those for a "reassurance force" or to integrate the air defence systems of NATO's eastern flank with that of Ukraine, have triggered positive reactions in Kyiv. However, the effects on Moscow of outlining Western plans to help Ukraine protect itself in the future – whether through direct military engagement or military-industrial cooperation – were and continue to be negative.

Paradoxically, the search for a stable ceasefire has made the end of the fighting more distant. The far-reaching suggestions by countries such as the UK and France – not least concerning troops from the Coalition of the Willing being stationed in western Ukraine – have increased the stakes for and wariness of the Kremlin concerning developments after the war. This has diminished Russia's – already low – willingness to seek compromise and make concessions. Such announcements have further reduced the Kremlin's readiness to cease the fighting before it has a clear advantage on the battlefield and increased its desire for a peace of victory (Siegfrieden) rather than a peace settlement (Verständigungsfrieden).

Indeed, Russia has categorically rejected the idea of foreign troops in Ukraine. As Russia's Foreign Minister Sergei Lavrov stated in March 2025: "The presence of troops from NATO countries under any flag, on Ukrainian soil is the same threat [as Ukraine's accession to NATO]. We do not accept it under any conditions".

Second, the various plans for guaranteeing Ukraine's future security contain little of substance that is of immediate material relevance. Instead, the much-discussed security guarantees are a collection of intentions, scenarios and promises that, if implemented, would partly enhance Ukraine's security through a symbolic troop presence, air policing and so on. Western plans do not foresee a principal improvement in either the international embeddedness or the military defensibility of Ukraine. Instead, official negotiations focus on the set-up, conditions for, formulation and ratification of certain future multilateral reaction mechanisms should Moscow re-escalate.

The – in itself noble – idea of security guarantees for Ukraine merely proposes that Kyiv trusts a certain algorithm of future Western actions of limited proportion. It also optimistically assumes that Moscow will believe in the feasibility and consequentiality of the proposed reactive algorithm. Yet, the so-far envisaged security guarantees foresee no organizational structure, such as NATO, to underpin them. Nor do they include a militarily significant presence of Western troops stationed along the future Russo-Ukrainian contact line. In the absence of serious institutional and sufficient material underpinnings, neither Kyiv nor Moscow can take security guarantees for Ukraine seriously.

Nonetheless, Ukraine may be forced to follow the "principle of hope" and accept the security guarantees it can get rather than the ones it needs. In such a case, however, any future ceasefire may turn out to be simply an interregnum until large-scale fighting resumes. Moreover, it would constitute a pause in the war to the advantage of Russia because it would allow Moscow to choose a convenient moment for re-escalation during, for example, a parallel military escalation in the South China Sea or elsewhere.

In contrast, the Ukrainian leadership – hoping that at least some of the promises made in the security arrangement are fulfilled – will be condemned to future military passivity and unpleasant surprises. In some ways, such a scenario would be a repeat of Ukraine's experience since 2014 of the now notorious 1994 "Memorandum on security assurances". Kyiv signed the Budapest Memorandum though there had been, in 1993, a Ukrainian request and draft for a full treaty between Ukraine and the P5 that would oblige each permanent member of the UN Security Council to take "necessary measures", if any nuclear weapon state makes a "threat or use of force or threat thereof in any shape against the territorial integrity and political independence of Ukraine".

Third, the current debate remains theoretical in so far as it cannot predict the concrete situation on the ground in which the security guarantees will eventually be provided to Ukraine. The exact way and conditions in which high-intensity fighting ends will shape the nature and sustainability of a future ceasefire. The position on the battleground and the socio-economic condition of both countries at the moment that weapons fall silent will principally determine the stability and length of the truce.

The content and formulation of future security guarantees will certainly also play a role. Not only will any future guarantees have to be adapted, however, to the existing environment in which they are provided. Their salience for their Western providers, Ukrainian recipient and Russian potential triggers will depend more on developments in the real world than on promises made on paper. Ukraine's position vis-à-vis Russia and vice versa will determine the meaning of any security guarantees, as will each country's relationships with third actors.

The more advantageous Ukraine's military, economic and international situation is at the moment a ceasefire begins, the less likely it will be that Western guarantees for Ukrainian security would have to be enforced. In contrast, the more difficult Ukraine's overall situation is when the fighting ends, the more likely a re-escalation and the more plausible a Ukrainian request to enact security guarantees might be.

Last but not least, Western public debate about future security guarantees for Ukraine in the past year has been characterized by inconsistency, contradictions and retractions. The exact role of the United States as provider of an ill-defined "back-stop" for the guarantees is still unclear. The size, location, type and even mere possibility of a Western "reassurance force" in Ukraine remain matters of controversy.

More recently, the Trump administration brought new uncertainty into European planning for a ceasefire in Ukraine when it announced its desire to annex Denmark's Greenland and started talks with Moscow on future economic cooperation. Given the US readiness to confront a close ally and collaborate with a traditional foe, European leaders, including those in Ukraine, have become mistrustful of US assurances to help implement future security guarantees.

In conclusion, the Western debate about security guarantees for Ukraine, which began in 2025, is a step in the right direction but premature and could even function as a form of escapism. Discussing the second step – securing the ceasefire – without a clear plan for how to accomplish the first – achieving that ceasefire – could distract from rather than help resolve the problem. This is especially the case since the success of the second step – the deterrent effect of the security guarantees on Russia – will be principally shaped by the nature of the first step – the way and the conditions in which the fighting ends in Ukraine.

Neither the conclusion of the current war nor the stability of a future ceasefire will be primarily determined by how security guarantees for Ukraine are formulated on paper. Instead of this or that verbal obligation of Western countries, the material situation on the ground – in the economic field and on the battleground – is decisive today and will remain crucial tomorrow. The type of material and financial help that Kyiv needs to end fighting in an acceptable way will in many ways be similar to the kind of support that Ukraine will need once a ceasefire is agreed to protect itself from a new attack.

Dr. Andreas Umland is a Policy Fellow at the newly founded European Policy Institute in Kyiv (EPIK), Associate Professor of Political Science at the Kyiv-Mohyla Academy (NaUKMA), and Analyst at the Stockholm Centre for Eastern European Studies (SCEEUS) in the Swedish Institute of International Affairs (UI).

The article is based on a recent EPIK Commentary.