When Joe Biden attended his first G7 summit as president in 2021, his message to U.S. allies was “America’s back.” Their response, the president recalled to TIME in a recent interview, was: “For how long?” Three years later, that question is at the top of European minds as they brace for the possibility—and, if recent polls are to be believed, probability—that Donald Trump could edge out Biden in the race for the White House in November.