In 1391, a wave of violence against Jews swept through Christian Spain. In its wake, thousands of Jews converted to Christianity. The following century saw more conversions as Spain became increasingly hostile toward its Jews. Some of these conversos—as they were called—quickly returned to Judaism after the violence abated; others lived outwardly as Christians while practicing Judaism in secret; others sought to assimilate completely into Christian society; and still others followed intermediate courses of action. The status of the conversos in Jewish law produced a substantial body of rabbinic scholarship, which is the subject of a recent book by Dora Zsom. Andrew Apostolou writes:

The question of how we deal with estranged Jews turns out to be an enduring one. Similar groups to the conversos emerged in the 19th and 20th centuries in such different societies as Germany, the Soviet Union, and now the United States. The debate over how to define Jewish identity in the new state of Israel, for example, led Ben-Gurion in 1958 to write to rabbis across the world to seek their opinion on “who is a Jew?” . . .

These contemporary concerns bring us back to the question of how much impact the rabbis had. [Dora] Zsom’s narrow focus means that she cannot draw out the effect of their decisions. What we know, according to Arthur Hertzberg in his classic entry in the Encyclopedia Judaica on “Jewish Identity,” is that those conversos who wanted to become Jews often forced the gates open: “the determining act was their willingness to become part of the Jewish community, and all the halakhic doubts of rabbinic authorities remained theoretical in the face of acts of return.”

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.