It would be a better world if anti-Semitic regimes put aside their hatreds to pursue their vital interests, but history militates against that illusion. You don’t need to invoke the famous and egregious example of Nazis diverting precious resources, trucks, and other war materials, in order to keep transporting Jews to the concentration camps. You don’t have to recall how some Nazis busily executed Jews even as they ran from the conquering allied troops. You can invoke Vichy, France, turning over the Jews who were its best and brightest, or the Soviet Union, which lost so much cultural and business acumen and capital through years of suppression. Anti-Semites cannot help themselves. To them, the injury is worthwhile if they can savage the Jews.
So without exploring the specifics of the deal, which are troubling, there is a ground-level assumption that Iran’s leaders share our fundamental interests in “having some semblance of legitimacy.” Granting that Iran is a sophisticated country, it’s also true that hatred of Israel and particularly, hatred of Jews, has proved a remarkably durable governing strategy in the modern world. How far will Iranians go, once some money is in hand, to pursue their destructive agenda? The belief that rational self-interest is a governing principle is a belief common to rational people.

In a world where countries are run by anti-Semites, being anti-Semitic is not necessarily less dangerous than misunderstanding anti-Semitism. We have just concluded a deal with people infected with the oldest and most virulent pathology of hatred the world has known. This is no time for celebration.