Two months ago, a crowd of protestors gathered in front of the Amsterdam Holocaust memorial, chanting an Arabic refrain, now familiar from such gatherings, that translates as “Khaybar, Khaybar, O Jews. The army of Mohammad is coming.” The reference is to a location in what is now Saudi Arabia, and to an oft-forgotten piece of Middle Eastern Jewish history. Lawrence Schiffman recounts this story, which begins in 622 CE, when the founder of Islam moved from Mecca to the city of Medina, which at the time was home to three large Jewish tribes.

This was Mohammad’s first regular contact with a full-scale Jewish community. Jews had a long history in the Arabian Peninsula, probably going back to [the 1st century CE]. There is considerable archaeological evidence for Jewish communities in southern Arabia, much of it in the form of cemetery inscriptions, going back as far as the 4th century CE. By the 7th century, some Jewish tribes had migrated north and establish themselves in agriculture—especially the cultivation of date palms—at Medina. In fact Jews were the majority of the population of this town.

Local Arab tribes had long been locked in a struggle for domination of the town, and they hoped that Mohammad would bring peace. While these tribes swore allegiance to Mohammad and accepted the new religion of Islam, they imposed a simple condition: that their Jewish neighbors who clung strongly to their faith would be protected. Little did the Arabs of Medina know that Mohammad would soon drive out two of the Jewish tribes and slaughter the men of the third, selling the women and children into slavery.

The turning point came after one of those tribes, the Banu Nadir, chose to sit out a battle rather than fight alongside the prophet—because they didn’t want to fight on Shabbat. When he was defeated, he took out his rage on these Jews:

[Mohammad] turned against the Nadir, besieged them, and ordered them to leave Medina. They surrendered [and] departed to the northeast, to the Jewish oasis of Khaybar, proudly marching through the streets of Medina in a caravan reported to have consisted of 600 camels, with music and fancy clothing. Two years later, the men of this Jewish tribe would be killed when Mohammad attacked Khaybar.

While it is commendable that administrators of several universities finally called upon police to crack down on violent and disruptive anti-Israel protests, the actions they have taken may be insufficient. At Columbia, demonstrators reestablished their encampment on the main quad after it had been cleared by the police, and the university seems reluctant to use force again. The school also decided to hold classes remotely until the end of the semester. Such moves, whatever their merits, do nothing to fix the factors that allowed campuses to become hotbeds of pro-Hamas activism in the first place. The editors of National Review examine how things go to this point:

Since the 10/7 massacre, Columbia’s Jewish students have been forced to endure routine calls for their execution. It shouldn’t have taken the slaughter, rape, and brutalization of Israeli Jews to expose chants like “Globalize the intifada” and “Death to the Zionist state” as calls for violence, but the university refused to intervene on behalf of its besieged students. When an Israeli student was beaten with a stick outside Columbia’s library, it occasioned little soul-searching from faculty. Indeed, it served only as the impetus to establish an “Anti-Semitism Task Force,” which subsequently expressed “serious concerns” about the university’s commitment to enforcing its codes of conduct against anti-Semitic violators.

But little was done. Indeed, as late as last month the school served as host to speakers who praised the 10/7 attacks and even “hijacking airplanes” as “important tactics that the Palestinian resistance have engaged in.”

The school’s lackadaisical approach created a permission structure to menace and harass Jewish students, and that’s what happened. . . . Now is the time finally to do something about this kind of harassment and associated acts of trespass and disorder. Yale did the right thing when police cleared out an encampment [on Monday]. But Columbia remains a daily reminder of what happens when freaks and haters are allowed to impose their will on campus.