At a large Iranian wedding I officiated this past Saturday night, I asked some of the attendees how they felt about the ban. A few expressed support, insisting that the inconsistencies will be smoothed away but the ban is a good idea. One or two said the U.S. cannot be naive about the world they themselves escaped.

But many more were troubled. Several knew Iranian Jews who were now barred from entry. One congregant pointed to a Muslim woman, a doctor, who was attending the wedding, and said that her family was now unable to join her. And then one older woman asked me—genuinely asking, as though I knew—what would have happened if the ban had been in effect in 1978?

Iranian Jews are a refugee community. The older members speak Farsi, the younger are navigating two civilizations. The extent of their wealth and success and talent makes it seem that they have both feet planted in the gilded soil of Beverly Hills—Iranian Jews were instrumental in the founding of giant enterprises from Qualcomm to Tinder. But underneath is the unease of people who in an instant lost everything—their homes, their past, their businesses, their sense of security.

And so they know, as Jews have always known in their bones, that as one man put it to me—"we could always swim and we were looking for a pool." Images of the children stranded in boats from Syria are not reminiscent of their grandparents, but of their earlier selves. As fiercely as they fear the importation of the hatred they knew in Iran to the United States, the people I spoke with understood that an indiscriminate ban, a closing of the iron gate on the desperate and ambitious, the creative and hopeful, was a tragedy for the families and for the country they now claim as their own.

Every country has a right to boundaries, borders, interests, and anxieties. There is evil in the world, and American Jews have the obligation to name it and be vigilant against its encroachment in their country. Jews know that Jihadist Islam is coming for us first, and that it is far harder to wipe out an ideology than an army. And many refugees, even well intentioned ones, arrive from parts of the world infected with the virus of anti-Semitism. American Jews have every cause to be vigilant.

Yet every crisis requires that we be informed by fear, but not controlled by panic. Judaism's greatest gift to the world was the idea that all human beings are created in the image of God. To see people fleeing—parents, children, grandparents—and to simply say, "We will not take them," is a betrayal of that gift.

Jews seeking refuge in the United States from Nazi Germany were suspected of being spies. Screenwriter Ben Hecht proposed buying 70,000 Jews, and told the U.S. government that if any were spies, it could shoot them. The proposal was rejected. Many of those Jews, who would have contributed immeasurably to America, doubtless died in the furnaces of Europe.