In Paris on Sept. 4, 2025, British Prime Minister Keir Starmer and French President Emmanuel Macron convened a meeting of a roughly 30-nation coalition to map security guarantees for a postwar Ukraine, even as fighting continues and U.S. support remains uncertain.
Key Takeaways
- About 30 countries belong to the broader “coalition of the willing”; a smaller “reassurance force” would deploy only after a ceasefire.
- French and U.K. leaders say the force needs clear U.S. backing; Washington’s position under President Trump has shifted away from pressing for a ceasefire.
- Coalition planners estimate a minimum force of 10,000 troops, with rotation needs raising the practical requirement to roughly 30,000 personnel.
- Experts warn deployment without robust U.S. intelligence and airpower would be highly risky and offer limited deterrence.
- Alternatives under discussion include supplying more weapons and ammunition to Kyiv rather than stationing large Western units inside Ukraine.
Verified Facts
The coalition meeting in Paris was hosted by President Emmanuel Macron and Prime Minister Keir Starmer on Sept. 4, 2025 to advance planning for security guarantees in a future post-conflict Ukraine. The gathering builds on months of talks among about 30 nations described as a “coalition of the willing.”
Negotiators distinguish a wider support group from a narrower “reassurance force.” French officials say 26 nations have pledged to contribute troops to that deterrent force, but they insist any deployment would follow a ceasefire and formal arrangements to reduce immediate combat risk.
British and independent analysts have outlined force-size benchmarks. Prime Minister Starmer has previously cited a baseline of roughly 10,000 troops; military planners note rotation, logistics and rest cycles could raise the practical requirement to nearer 30,000. Some analysts estimate a U.K. contribution might look like a 5,000-strong brigade on paper, expanding to 15,000 in operational terms when accounting for rotation.
U.S. involvement remains central. In August 2025, President Donald Trump met Russian President Vladimir Putin in Alaska (Aug. 15) and then met European leaders in Washington on Aug. 18. Trump’s public comments signaled a shift from calling explicitly for a ceasefire to emphasizing a negotiated peace, and he has not endorsed new, far-reaching economic measures against Moscow since those meetings.
Security experts at institutions such as the Royal United Services Institute (RUSI) and the Foundation for Strategic Research caution that the deterrent value of a reassurance force depends heavily on American intelligence, surveillance and airpower support provided from outside Ukraine.
Context & Impact
A deployment decision touches several strategic and political fault lines: the credibility of transatlantic guarantees, the military readiness of European armies, and the domestic politics of countries where populist parties have been gaining ground.
If the U.S. provides clear, sustained backing, a multinational reassurance presence could bolster Kyiv’s long-term security. If Washington wavers, European governments may have to choose between assuming far greater military risk themselves or accelerating arms deliveries instead of stationing troops.
- Defense budgets: European states may increase spending to sustain long-term commitments to Ukraine’s security.
- Alliance cohesion: Repeated reversals or vague pledges from key partners could erode trust among coalition members.
- Risk management: Stationing forces away from front lines reduces but does not eliminate exposure to missile and drone strikes.
Official Statements
“There is no suggestion troops will be deployed without a ceasefire.”
François Heisbourg, Foundation for Strategic Research
Explainer
Unconfirmed
- Whether the United States will commit combat air support or strike capabilities in response to ceasefire violations.
- Whether President Vladimir Putin would accept a ceasefire framework that preserves Ukrainian sovereignty in contested areas.
- The exact troop numbers each coalition country will provide and the final command arrangements for any reassurance force.
Bottom Line
European leaders face a difficult trade-off: accept a fragile, largely symbolic guarantee unless backed by decisive U.S. support, or prepare to shoulder heavier military responsibilities and cost themselves. In practice, many governments are weighing a near-term mix of stepped-up arms deliveries to Kyiv and detailed contingency planning for a reassurance presence that would only deploy after a verified ceasefire.
Decisions made in Paris and subsequent talks will shape Kyiv’s security options and Europe’s defense posture for years to come.