Finnish President Alexander Stubb said on Thursday that he has “no concerns” about US President Joe Biden’s capacity to lead, amid growing anxiety among supporters of his Democratic Party that the 81-year-old is no longer mentally fit enough. “I have absolutely no concerns about the capacity of the current president of the United States to lead his country and to lead our fight for Ukraine and to lead NATO,” Stubb told reporters at a NATO summit in Washington, which began on Tuesday. “I’ve had the opportunity to speak to President Biden on many occasions during the past 48 hours,” Stubb said. …