On 27 October 2018 Bari Weiss's childhood synagogue in Pittsburgh became the site of the deadliest attack on Jews in American history. For most of us, the massacre came as a total shock. But to those who have been paying attention, it was only a more violent, extreme expression of the broader trend that has been sweeping Europe and the United States for the past two decades. No longer the exclusive province of the far right and far left, anti-Semitism...