In July 2020, Keir Starmer stepped before the cameras for the first time as leader of the opposition Labour Party, standing beside his wife outside their red-brick Victorian terrace in the north London suburb of Kentish Town. Almost five years later, just before his first anniversary as British prime minister, a 21-year-old Ukrainian set the entrance to their Kentish Town home on fire, lighting a rolled newspaper with liquid accelerant and matches and placing it against the entrance.