In a recent radio interview, Rashid Khalidi—a distinguished professor of Arab studies at Columbia University—voiced his fear that Jewish supporters of Israel would “infest” the Trump administration, using that verb not once but three times. Dore Feith, a former student of Khalid’s, responds:

[Khalidi’s] remarks may not be the ugliest comments along these lines that ever emerged from the Middle East-studies faculty at Columbia. . . . But the “infestation” theme is nasty enough to warrant special notice. What makes it nasty is its historical resonance. To be sure, not all criticism of Israel is anti-Semitism and not all anti-Semitism is Nazism. But there’s no getting around the fact that in his memoir Mein Kampf, Hitler over and over again described the Jews as an infestation of vermin. That was one of the book’s main metaphors. And that’s why Nazi officials made a point of saying their Jewish policy aimed not to “kill” but to “exterminate” (vernichten), a word more appropriate for bugs or lice than human beings. . . .

In [a statement given to the Forward in response to criticism of his words, Khalidi] acknowledged “infelicitous phrasing,” but that’s even less of an apology than the classic non-apology “I’m sorry if anyone took offense.” In an e-mail to me, he then renewed his attack on “these people” as having “a racialist disregard for Palestinians” and using “anti-Muslim, anti-Palestinian, and anti-international-law rhetoric.” In other words, Khalidi doubled down on his insult when he should have simply said “sorry.” Rather than granting that both sides of the Palestinian-Israeli conflict have points worth hearing, Khalidi painted Israel’s supporters as crazy extremists who lack rational arguments and who don’t deserve serious consideration.

Many good people are puzzled at how the Arab-Israeli conflict can fester and rage for more than 100 years. A key reason is that Israel’s enemies are so passionate in their hatred that they pass it down through the generations. Rashid Khalidi’s uncivil words demonstrate the problem. They damage the very people he favors. After all, the Palestinian people would benefit from mutual accommodation and peace with Israel. And his words also harm the interests of Columbia students who hope to have mutually respectful exchanges of ideas about controversial subjects.

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.