That the rise in incidents was in Germany made the government report all the more concerning. But anti-Semitism is on the rise all across Europe, as well as in the United States. France reported an increase of 74 percent in anti-Semitic acts in a single year, with 541 incidents reported in 2018, including widely viewed videotaped insults shouted at the French Jewish intellectual Alain Finkielkraut during one of the Yellow Vest protests. In Britain, nine Labour members of Parliament quit their party in part over the cloud of anti-Semitism hanging over the party leader, Jeremy Corbyn.

In the United States, attacks on synagogues by white-supremacist gunmen have led the growing list of assaults on Jews. The Anti-Defamation League reported that these attacks more than doubled from 2017 to 2018, to 39 , part of a total of 1,879 anti-Semitic incidents. There has also been a marked rise in the political weaponization of anti-Semitism by both left and right, often played out in debates on criticizing or supporting Israel. Prime Minister Benjamin Netanyahu has not helped matters by finding common cause with nationalist leaders like the Hungarian Prime Minister Viktor Orban or President Trump so long as they do not support a Palestinian state.

A tally of incidents does not tell the full story. To a degree, the numbers reflect the way hate speech, intolerance, anger and once-taboo themes have found their way into the open on social media or via populist movements, allowing hatred of Jews to come out of the shadows. But far-right and far-left politicians have often learned to project themselves as defenders of Jews while drawing on blatantly anti-Semitic tropes, as Mr. Orban has done in Hungary. Among the Muslims of Europe, and among some leftists, a resentment of Israel often crosses into hostility to all Jews.

What is clear is that these strains of anti-Semitism — from the right, from the left and from radical Muslims — have morphed into a resurgence of a blight that should have been eradicated long ago, and that is causing serious anxiety among Europe’s Jews.

A CNN poll last November on the state of anti-Semitism in Europe found that a third of respondents said they knew little or nothing about the Holocaust. Nearly a quarter said Jews had too much influence in conflict and wars; more than a quarter said they believed that Jews had too much influence in business and finance. A 2015 survey by the Anti-Defamation League found that 51 percent of Germans believed it was “probably true” that “Jews still talk too much about what happened to them in the Holocaust.” These are the stereotypes that make anti-Semitism an especially pernicious form of bigotry, a grand conspiracy theory in which Jews spread evil in their countries through some illusory subterfuge, whether controlling capital, or the media, or whatever.