Written by: Nicola Bonsegna
Supervised by: Vittoria Montinari
Edited by: Jack Kirk
On 10 April 2025, NATO hosted the last of a series of meetings of the so-called ‘coalition of the willing’ (Gray & Van Overstraeten, 2025). The initiative, spearheaded by British Prime Minister Keir Starmer and supported by French President Emmanuel Macron, was first introduced at the London Summit on Ukraine in March (Davies, 2025). Bringing together defence ministers from 30 nations, including Canada and Australia but excluding the United States (US), the coalition aims to establish a ‘reassurance force’ for Ukraine in the event of a ceasefire with Russia (Melkozerova, 2025). The group seeks a credible and lasting European-made peace, reducing the chances of a future invasion from Russia even without US security guarantees promised to the war-torn country. In the words of the British Defence Secretary, the aim is to “put Ukraine in the strongest possible position, to protect its sovereignty and deter further Russian aggression” (Gray & Van Overstraeten, 2025). The urgency of the project has grown amid declining U.S. support under the Trump administration, which has pushed Europe to assume greater responsibility for its own security as Washington pivots its strategic focus toward the Pacific.
The coalition considers Ukraine’s security essential to Euro-Atlantic stability, underscoring that any peace deal must protect Ukraine’s sovereignty while deterring future aggression (UK Ministry of Defence, 2025; Gray & Van Overstraeten, 2025). Its implementation relies on a concrete operational focus across land, air, and sea domains, coupled with increased support for Ukraine’s armed forces. As the French Defence Minister stressed, ensuring Ukraine’s security begins with sustained support for its armed forces and a firm rejection of any form of demilitarisation. (Gray & Van Overstraeten, 2025). Despite Ukraine possessing one of the most capable and numerous armies in Europe, its path to NATO membership remains blocked largely due to U.S. resistance (Melkozerova, 2025). The combination of this and Washington’s declared reduction in support has prompted the proposal to deploy international forces in the war-torn country, to ensure peace and deter further Russian aggression. The presence of foreign troops on the ground could serve as a deterrent, but could also raise concerns about a perceived direct confrontation with Russia. An escalation could be problematic not only for Europe but for the international community as a whole, given the risk of triggering a wider, possibly global, conflict. Russia has stated that foreign troops’ deployment without a UN mandate, which requires the approval of all five UNSC permanent members including Russia, would be unacceptable from the standpoint of international law.
Significant and unresolved challenges to implementation remain. Key aspects such as troop contributions, rules of engagement, operational scope, and, most importantly, the specific mission and mandate of the coalition have yet to be clearly defined. EU High Representative Kaja Kallas questioned the exact role of this reassurance force and whether it was intended for deterrence, monitoring, or peacekeeping, highlighting the necessity of clarifying these critical details before proceeding further (Tidey, 2025). Several European officials also stress the essential need for U.S. logistical and intelligence support, which the Trump administration has explicitly declined (Gray & Van Overstraeten, 2025). Italy, among others, remains hesitant about deploying troops without U.S. involvement. Despite repeated diplomatic engagements by Macron and Starmer with President Trump, the U.S. has consistently refused participation in the coalition (Tidey, 2025). President Macron in particular remains committed to moving forward, urging Europe to prepare for action even in the absence of U.S. support (Irish & Pineau, 2025). Although consensus has not been achieved, Macron highlighted that unanimity is not necessary, as some countries are ready to contribute with land troops and others with air and maritime support. Certain states remain opposed due to concerns over costs, manpower shortages, and the risk of direct conflict with Russia.
In this context, Europe’s ability to act decisively without its long-standing security guarantor, the United States, remains uncertain. The war in Ukraine has exposed the fragility of Europe’s defence architecture and the limits of its strategic cohesion. Fragmentation among EU and NATO member states, driven by differing interests, capacities, and threat perceptions, continues to hinder a unified response.
The ‘Coalition of the Willing’ represents a test for Europe’s capacity to move from rhetorical commitment to action to demonstrate genuine strategic autonomy. Beyond Ukraine’s security, the credibility of European defence and deterrence is at stake. Success will depend on overcoming internal fragmentation and generating political will, mobilising credible military and logistical capabilities, establishing a clear, lawful mandate and building resilience against both internal divisions and external pressures. This will signal that Europe is prepared to take decisive, collective action in the face of evolving security challenges. If successful, the initiative could mark a turning point in Europe’s pursuit of strategic autonomy and a decisive break from post-Cold War dependency on U.S. leadership. Failure will reinforce doubts about Europe’s ability to manage its own security and respond to high-stakes crises as a coherent and credible geopolitical actor.
Bibliography:
Associated Press. (2025, April 5). Zelenskyy meets European military leaders to plan for a peacekeeping force. AP News. https://apnews.com/article/russia-ukraine-war-kryvyi-rih-dnipropetrovsk-fcdb5bbec7a51365b08e8ef2884ba22f
Davies, C. (2025, March 2). Starmer’s plan for peace in Ukraine: Key takeaways from London summit. The Guardian. https://www.theguardian.com/world/2025/mar/02/keir-starmer-peace-talks-ukraine-key-takeaways-london-summit
Galbreath, D. J. (2025, February 14). US makes clear Europe’s security isn’t a Trump priority. Asia Times. https://asiatimes.com/2025/02/us-makes-clear-europes-security-isnt-a-trump-priority/
Gray, A., & Van Overstraeten, B. (2025, April 10). Europeans discuss Ukraine peace force but big questions still open. Reuters. https://www.reuters.com/world/europe/europeans-discuss-ukraine-peace-force-big-questions-unanswered-2025-04-10/
Irish, J., & Pineau, E. (2025, March 27). Europeans back strong Ukraine army, differ on future ‘reassurance force’. Reuters. https://www.reuters.com/world/europe/ukraines-allies-meet-with-new-aid-security-assurances-mind-2025-03-27/
Melkozerova, V. (2025, April 10). Ukraine lays out peacekeeping mission wish list. Politico. https://www.politico.eu/article/ukraine-kyiv-western-troop-peacekeaping-mission-russia/
Ministry of Defence. (2025, April 11). Coalition of the Willing: Joint UK-France statement following 10 April meeting. GOV.UK. https://www.gov.uk/government/news/coalition-of-the-willing-joint-uk-france-statement-following-10-april-meeting
Tidey, A. (2025, April 10). ‘Coalition of the Willing’ plans now ‘well developed’ but timeline, numbers still to be worked out. Euronews. https://www.euronews.com/my-europe/2025/04/10/defence-ministers-from-coalition-of-the-willing-for-ukraine-meet-once-again-without-the-us
Wintour, P. (2025, February 14). JD Vance stuns Munich conference with blistering attack on Europe’s leaders. The Guardian. https://www.theguardian.com/us-news/2025/feb/14/jd-vance-stuns-munich-conference-with-blistering-attack-on-europes-leaders
