Exclusive: Alexander Stubb says a plausible deterrent and ‘American backstop’ are needed in the event of a future peace deal

Finland’s president, Alexander Stubb, has said security guarantees for Ukraine, which are being discussed by the so-called “coalition of the willing”, would compel the European countries that sign to fight Russia if Moscow launched military action against Ukraine again in future.

“Security guarantees in essence are a deterrent. That deterrent has to be plausible and in order for it to be plausible it has to be strong,” Stubb told the Guardian, in an interview in Helsinki before travelling to New York for the UN general assembly.