In just over a year, the U.S. has witnessed three mass-shootings of Jews, among many other signs of rising and more visible anti-Semitism. Yossi Klein Halevy holds up the success of Anglo-Jewry in presenting a united front against Jeremy Corbyn, and in joining forces with sympathetic non-Jews, as a useful model for American Jews. A similar approach, he notes, characterized American-Jewish efforts on behalf of Soviet Jewry:

The Jewish pushback against Corbynism united British Jewry and isolated its far-left extremists, created alliances with prominent non-Jews, and helped to convince many non-Jewish voters that a Prime Minister Corbyn would be toxic for England precisely because he would be toxic for its Jews.

Prominent Labor leaders, along with cultural figures like J.K. Rowling and John Le Carré, broke with Corbyn and stood with the Jews. When the British chief rabbi Ephraim Mirvis took the unprecedented step of warning about the danger of Corbyn-led Britain, the archbishop of Canterbury, Justin Welby, publicly affirmed the legitimacy of his anxiety. This, too, was a result of decades of Jewish-Christian dialogue efforts.

Whether consciously or not, British Jewry adopted the playbook developed a generation ago by the international protest movement to free Soviet Jewry. . . . One of the challenges facing the Soviet Jewry movement in its early years was how to overcome the notion, widespread among many on the left around the world, that the Soviet Union, for all its “mistakes” under Stalin, still represented a humane alternative to the capitalist West. . . . British Jews today [similarly] understood that the great threat to their wellbeing now came from precisely the camp that had for generations largely defined British Jewish political identity.

In their campaign against Corbynism, Britain’s Jewish leaders kept the dividing line within the Jewish community to a bare minimum. The line didn’t run between left and right, Orthodox and non-Orthodox, but between the overwhelming majority of the Jewish community and Corbyn’s Jewish apologists. . . . Once Jews summon the courage to define threat and publicly resist it, non-Jewish allies appear.

Two extraordinary events demonstrate something important about Israel’s most fervent adversaries. One was a speech given at something called The People’s Forum (funded generously by Goldman Sachs), which stated, “When the state of Israel is finally destroyed and erased from history, that will be the single most important blow we can give to destroying capitalism and imperialism.”

The suggestion that this tiny state is the linchpin of a global, centuries-old phenomenon like capitalism goes well beyond anything resembling rational criticism. Even if Israel were guilty of genocide, apartheid, and oppression—which of course it is not—it would not follow that its destruction would help end capitalism or imperialism.

The other was an anti-Israel protest that took place in front of New York City’s Memorial Sloan Kettering Cancer Center, deemed “complicit” in Israel’s evils. At organizers’ urging, participants shouted their slogans at kids in the cancer ward, who were watching from the windows. Given Hamas’s indifference toward the lives of Gazan children, such callousness toward non-Palestinian children from Hamas’s Western allies shouldn’t be surprising. The protest—like the abovementioned speech—deliberately conveyed the message that Israel is the ultimate evil and its destruction the ultimate good, cancer patients be damned.

The fact that Israel’s adversaries are almost comically perverse does not mean that they can be dismissed. If its allies fail to understand the obsessive and irrational hatred that it faces, they cannot effectively help it defend itself.