The jolt to Labour seems to have galvanized the party to confront the seeping infiltration of anti-Semitism. Tom Watson, the deputy leader, has called on Corbyn to expel Labour members accused of anti-Semitism. They’ve tended to face mild reprimands, if that. John McDonnell, the shadow chancellor, said there’d been “a lot of listening but not enough action.” Jon Lansman, a founder of the Momentum organization that has supported Corbyn, now says there is “a major problem” with “hard-core anti-Semitic opinion.” Where have these guys been in recent years during what Pat McFadden, another Labour M.P., described to me as “open season for the abuse of my Jewish colleagues”?

In a typical incident this week, a Labour M.P. who is a Corbyn ally, Chris Williamson, tried to express regret for saying the party had been “too apologetic” about anti-Semitism, only to claim in his “apology” that it is “often forgotten” how few cases of anti-Semitism there are. He has been suspended.

Under Corbyn, actions have usually lagged words. The party decided in 2016 that “Zio,” an insult used by the Ku Klux Klan, was unacceptable. Its use persists as an abbreviation of Zionist, itself turned into a dirty word.

“I am very proud and very relaxed about the fact that I openly support the creation of the State of Israel and the right for the Jewish people to have a homeland,” Berger said, noting that she’s a Zionist but “others have sought to hijack the word” and “we know” what “language can inspire and what actions it can result in.”

We do. This month, Yellow Vest protesters in Paris accosted Alain Finkielkraut, a leading French essayist and the son of an Auschwitz survivor. Their abuse included cries of “Back to Tel Aviv” and “France belongs to us.” A Jewish cemetery was desecrated. Anti-Semitic incidents rose 74 percent in France in 2018.

The eternal Jewish ogre resurfaces — a convenient scapegoat for economic resentments, precariousness, fear, frustration or Israel’s oppression of Palestinians. Corbyn, wittingly or not, has fed this poison, as his party is now realizing. He has made an irrefutable case for Israel through Labour’s abetting of revived European Jew hatred.

The fundamental link between European anti-Semitism, annihilationist at its apogee, and the decision of Jews to embrace Zionism in the conviction that only a Jewish homeland could keep them safe is something contemporary European theorists of a demonic Israel prefer to forget. This amnesia is an additional reason that I, too, like Berger, am a proud Zionist.