Ironically, Hamas’s gruesome attack on Israeli civilians on October 7, instead of unleashing a flood of criticism of jihadist Muslims, has turned up the fire under the apparently ever-simmering cauldron of anti-Semitism. Everyone seems focused on Jews — even obsessed with them. But the loudest voices are those raised in condemnation of the Israelis, their supporters, and worldwide Jewry. There are a number of tropes that Jew-haters dredge up on such occasions: the debunked but widely disseminated Soviet psy-op pamphlet The Protocols of the Elders of Zion; the Jews as Christ-killers; the popular trope that the Jews “own the banks”;...