Mark Zuckerberg, the founder and CEO of Facebook, recently defended his company’s policy of not removing posts denying the Holocaust, stating, “I don’t think that [the authors are] intentionally getting it wrong; . . . as abhorrent as some of those examples are, I think the reality is also that I get things wrong when I speak publicly. I’m sure you do. . . . I just don’t think that it is the right thing to say, ‘We’re going to take someone off the platform if he gets things wrong.’” Regardless of what Facebook’s policies should be, Deborah Lipstadt points to a dangerous flaw in Zuckerberg’s reasoning:

Deniers are a . . . type of neo-Nazi. . . . Wolves in sheep’s clothing, they don’t bother with the physical trappings of Nazism—salutes, songs, and banners—but proclaim themselves “revisionists”—serious scholars who simply wished to correct “mistakes” in the historical record. This is extremism posing as rational discourse. And his statements suggest that Zuckerberg has been duped by them into thinking that they’re any different than someone who proudly wears a swastika. . . .

In 2000, when I was on trial in London for libel, having been sued by David Irving—then one of the world’s leading Holocaust deniers—for having called him a denier in one of my books, my defense team tracked all of his “proofs” back to their sources and found that imbedded in each of his historical claims was a falsification, invention, distortion, change of date, or some other form of untruth. Once these lies were exposed, his argument [that he wrote history in good faith] collapsed. . . .

Holocaust denial is not about history. A form of anti-Semitism, it’s about attacking, discrediting, and demonizing Jews. The deniers’ claims—that the Jews planted evidence, got German prisoners of war to admit falsely to crimes, and forced postwar Germany to shoulder a tremendous financial and moral burden—are predicated on the notion of the mythical power of the Jews, which was extensive enough to realize this vast conspiracy. These assertions rely on classic anti-Semitic tropes, some of which are over 2,000 years old.

Deniers, who today clearly feel more emboldened than ever before, are not the equivalents of flat-earth theorists, nor are they just plain loonies. . . . Their agenda is to reinforce and spread the very hatred that produced the Holocaust.

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.