After taking offense at Canadian Prime Minister Mark Carney’s more assertive stance toward Washington, Trump withdrew an invitation for him to join his Board of Peace, an organization chaired by Trump that some Western allies distrust as a potential rival to the United Nations. He has also used economic pressure against allies, threatening tariffs on Switzerland after a tense phone call and warning Denmark that rejecting U.S. control over Greenland would have consequences, raising concerns about strain on NATO. Camille Knight reports.