Even with British understatement that’s clear enough: Corbyn’s Labour Party has given free rein to anti-Semites.

Last June, Corbyn compared Israel to “self-styled Islamic states or organizations” — an allusion his staff insisted was to Muslim nations rather than the terrorist Islamic State, although Pakistan is not “self-styled” and ISIS is. He has been largely passive as Jewish Labour MP’s, including Luciana Berger and Ruth Smeeth, have had anti-Semitic insults hurled at them either in person or online. He elevated Baroness Chakrabarti to a peerage after she whitewashed Labour in an earlier report on anti-Semitism that spoke of “unhappy incidents” (oh, yes, so awfully unhappy) — a decision that left a “damaging impression,” in the words of the latest inquiry. He has called Hamas and Hezbollah agents “of long-term peace and social justice and political justice in the whole region,” and once invited to Parliament a Palestinian Islamist, Raed Salah, who has suggested Jews were absent from the World Trade Center on 9/11. He has attended an event organized by a pro-Palestinian group founded by an avowed Holocaust denier, Paul Eisen. He has permitted the word “Zio” — an anti-Semitic term used by the Ku Klux Klan — to become the modish slur in Labour circles on campuses and elsewhere.

Corbyn has rejected the cross-party report, saying it’s biased. Last month he called anti-Semitism “an evil” that must never be permitted “to fester in our society again.” He’s expressed regret for his embrace of Hamas and Hezbollah. Nobody believes him. The Labour leader hates the West and by extension Israel as a colonial power (not in the West Bank, where the settler movement makes the charge justifiable, but in its entirety) so much that he cannot see when this hatred merges into anti-Semitism. “He’s in denial,” as Rachel Sylvester of The Times of London told me. His ideology leads to a position that Johnson expresses well: “That which the demonological Jew once was, demonological Israel now is.”

Parry Mitchell, a Jewish peer, quit the Labour Party in disgust this summer, and put the issue this way to me: “How can I, a Jew and a Zionist, remain in a party where the leadership is so clearly hostile to Israel (even to its very existence) and which also flirts with anti-Semitism.”

British and American politics have reached a new low that presents the greatest postwar challenge to the Atlantic alliance and the civilization it has sustained.