The contemporary left’s hatred of Israel and indifference (or worse) toward the virulent anti-Semitism of radical Islamists come as a surprise to many. But, writes Robert Wistrich, socialists have a long history of underestimating, ignoring, and even encouraging anti-Semitism:

In 1893, the German labor leader August Bebel breezily dismissed anti-Semitism as the “socialism of fools.” From then to the present day, the Western left has been disturbingly complacent about Judeophobia. Communists and socialists of various stripes have persistently underestimated the impact, distinctiveness, and longevity of anti-Semitism. Even today, significant strains of the American and even the Israeli left are far less exercised about global anti-Semitism than about the supposed transgressions of the Jewish state. A review of the hard left’s various answers to the “Jewish Question” makes clear that equivocation on anti-Semitism and antipathy toward Israel are enduring, complementary elements in Marxism’s wrongheaded materialist interpretation of world affairs.

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.