BERLIN - Faced with U.S. demands to provide the military muscle to enforce a future Ukraine peace deal, Europe finds itself in a bind.

Experts say that sending European peacekeepers to Ukraine might stretch and weaken NATO's own defences, and that the mission would still need U.S. support to succeed.

While U.S. boots on the ground may not be necessary, deterrence in the form of U.S. medium-range missiles and ultimately nuclear weapons will remain crucial.

"I'm not sure that any security guarantee will be 100% credible against an aggressive and nationalistic Putin unless it involves the Americans in some way," said Mark Lyall Grant, Britain's national security adviser during part of Trump's first term.

European officials also say only a U.S. guarantee would protect European peacekeepers and deter Russia from any future attack on Ukraine.

Last week, U.S. President Donald Trump shocked Europeans by arranging bilateral peace talks with Russia, which were launched on Tuesday in Riyadh, while Defense Secretary Pete Hegseth told allies that "any security guarantee must be backed by capable European and non-European troops".

He made clear U.S. troops would not be sent to Ukraine.

At an emergency meeting in Paris on Monday, European leaders remained split on the idea of deploying peacekeepers to Ukraine, a plan some European nations had started discussing last year at France's initiative.

Such a force would raise the risk of a direct confrontation with Russia and stretch European militaries, whose arms stocks have been depleted by donations to Ukraine and who are used to relying heavily on U.S. support for major missions.

On Monday, British Prime Minister Keir Starmer said he was willing to send troops to Ukraine but there would need to be a U.S. "backstop" as well.

COULD EUROPEAN PEACEKEEPING DEPLOYMENT WEAKEN NATO?

Experts warn that deploying a large European force to Ukraine might weaken NATO's defences against a wider and growing threat from Russia as a halt to the conflict would enable its war economy to replenish military stockpiles rapidly.

Some also doubt whether European countries, who have been struggling to boost readiness after decades of relative peace since the Cold War ended, could quickly raise enough combat-ready troops, especially if they were asked to secure more than 2,000 km of contact line with Russia and Moscow's ally Belarus.

Claudia Major, an analyst for the German SWP think tank, said assembling such a peace force was barely achievable for the Europeans on t...