Last year, on International Holocaust Remembrance Day, Mohammad al-Issa, in his capacity as secretary-general of the Muslim World League, wrote an unprecedented open letter to the director of the U.S. Holocaust Memorial Museum expressing Muslim sympathy for the victims of the Holocaust. The following May, Issa—formerly Saudi Arabia’s justice minister—made a historic visit to the museum. Marking this year’s Holocaust Remembrance Day, which fell on Sunday, he writes:

For decades, . . . some have chosen not to see what really happened wherever the Nazis and their henchmen wielded power. Instead, they deny the horrors of a diabolical plan to implement a hateful idea of racial purity that ultimately led to the murder of millions of innocent men, women, and children—including six million Jews. . . .

I urge all Muslims to learn the history of the Holocaust, to visit memorials and museums to this horrific event, and to teach its lessons to their children. As adherents of a faith committed to tolerance, coexistence, and respect for the dignity of all mankind, we share a responsibility to confront those who would carry Adolf Hitler’s torch today, and to join hands with people of goodwill of all nations and faiths to prevent genocide wherever it threatens innocent lives.

We can only do this if we are armed with the truth. We Muslims share the sentiment expressed by Elie Wiesel in the words engraved in stone on the walls of the Holocaust Museum, “For the dead and the living, we must bear witness.” As the Holy Quran commands, “O you, who believe, be upright for God and be bearers of witness with justice!”

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.