European countries would be compelled to fight if Moscow launched further military action against Ukraine as part of post-war security guarantees being discussed by the “coalition of the willing”, Finland’s president has said.
Alexander Stubb said that any security guarantees negotiated in order to bring the three-and-a-half year long war to a close would have to act as “a strong” deterrent for a future invasion by Moscow.
“That deterrent has to be plausible and in order for it to be plausible it has to be strong,” he told the Guardian in an interview in Helsinki before travelling to New York for the UN general assembly.
It comes after French president Emmanuel Macron told reporters that 26 nations had committed to be part of a “reassurance force” in Ukraine, which includes military presence “on the ground, in the sea or in the air”.
Asked if security guarantees would mean European countries promising to engage militarily with Russia in an instance of future aggression against Ukraine, President Stubb told the newspaper: “That is the idea of security guarantees by definition.”
He said the guarantees would only come into effect after a future peace deal between Ukraine and Russia, but Moscow would have “absolutely no say in the sovereign decisions of an independent nation state”.
“Security guarantees in essence are a deterrent and that deterrent has to be plausible, and in order for it to be plausible it has to be strong. And that means also strategic communication, so we’re not making security guarantees into the air, but we’re making real security guarantees and Russia knows that,” he said.

Mr Stubb has become a key figure in peace negotiations, forging a close bond with US president Donald Trump, who he is in regular contact with “by phone and other means” with a bilateral meeting upcoming this week, according to the newspaper.
“I think it’s the job of the president of Finland to get along with the president of the United States, whoever he is,” President Stubb said.
“Foreign policy is always based on three pillars. It’s values, interests and power. Small states only have values and interests … but we can have influence instead of power. Engagement is better than disengagement, come hell or high water.”
He has insisted that an “American backstop” remains necessary to give Ukraine any real force, conceding it remained clear what the Trump administration was willing to agree to.
Trump’s patience appears to be waning for Putin after a Russian fighter jet incursion in Estonia, he told reporters: "I don't like when that happens. It could be big trouble, but I'll let you know later."
Estonia joins Poland and Romania as neighbouring European countries who have had their airspace invaded by Russia jets and drones in the last couple of weeks.
Estonian officials maintained on Saturday that there was no need to trigger Article 5, NATO's collective defence clause, despite the repeated violations by Russian jets and drones, as well as allegations from Western officials that Moscow is waging a hybrid war against the West including a sabotage campaign, cyberattacks and influence operations.