At an 18 February 2017 rally, Donald Trump railed against immigrants and violence. He was unusually focused on Sweden, warning the crowd about recent terrorist attacks in the country: “You look at what’s happening last night in Sweden. Sweden, who would believe this?” If a terrorist attack in Sweden seemed unbelievable, it’s because it was. There had been no attack by immigrants the night before Trump spoke. The most recent attacks on Sweden, at the time, were a series of bombings between November 2016 and January 2017 that were allegedly connected to the neo-Nazi group the Nordic Resistance. People in...