​ The Rational Ayatollah Hypothesis If President Obama can forgive us our trespasses, he can forgive the Ayatollah Khamenei’s, too.

By Bret Stephens

May 25, 2015 6:05 p.m. ET

Can there be a rational, negotiable, relatively reasonable bigot? Barack Obama thinks so.

So we learn from the president’s interview last week with the Atlantic’s Jeffrey Goldberg—the same interview in which Mr. Obama called Islamic State’s capture of Ramadi a “tactical setback.” Mr. Goldberg asked the president to reconcile his view of an Iranian regime steeped in “venomous anti-Semitism” with his claims that the same regime “is practical, and is responsive to incentive, and shows signs of rationality.”

The president didn’t miss a beat. Supreme Leader Ali Khamenei’s strategic objectives, he said, were not dictated by prejudice alone. Sure, the Iranians could make irrational decisions “with respect to trying to use anti-Semitic rhetoric as an organizing tool.” They might also pursue hate-based policies “where the costs are low.” But the regime has larger goals: “maintaining power, having some semblance of legitimacy inside their country,” and getting “out of the deep economic rut that we’ve put them in.”

Also, Mr. Obama reminded Mr. Goldberg, “there were deep strains of anti-Semitism in this country,” to say nothing of Europe. If the president can forgive us our trespasses, he can forgive the ayatollah’s, too.

Perhaps it shouldn’t be surprising that a man with an undergraduate’s enthusiasm for moral equivalency (Islamic State now, the Crusades and Inquisition then) would have sophomoric ideas about the nature and history of anti-Semitism. So let’s recall some basic facts.

Iran has no border, and no territorial dispute, with Israel. The two countries have a common enemy in Islamic State and other radical Sunni groups. Historically and religiously, Jews have always felt a special debt to Persia. Tehran and Jerusalem were de facto allies until 1979, when Ayatollah Khomeini came to power and 100,000 Jews still lived in Iran. Today, no more than 10,000 Jews are left.

So on the basis of what self-interest does Iran arm and subsidize Hamas, probably devoting more than $1 billion of (scarce) dollars to the effort? What’s the economic rationale for hosting conferences of Holocaust deniers in Tehran, thereby gratuitously damaging ties to otherwise eager economic partners such as Germany and France? What was the political logic to Mahmoud Ahmadinejad’s calls to wipe Israel off the map, which made it so much easier for the U.S. and Europe to impose sanctions? How does the regime shore up its domestic legitimacy by preaching a state ideology that makes the country a global pariah?

Maybe all this behavior serves Tehran’s instrumental purposes by putting the regime at the vanguard of a united Shiite-Sunni “resistance” to Western imperialism and Zionism. If so, it hasn’t worked out too well, as the rise of Islamic State shows. The likelier explanation is that the regime believes what it says, practices what it preaches, and is willing to pay a steep price for doing so.

So it goes with hating Jews. There are casual bigots who may think of Jews as greedy or uncouth, but otherwise aren’t obsessed by their prejudices. But the Jew-hatred of the Iranian regime is of the cosmic variety: Jews, or Zionists, as the agents of everything that is wrong in this world, from poverty and drug addiction to conflict and genocide. If Zionism is the root of evil, then anti-Zionism is the greatest good—a cause to which one might be prepared to sacrifice a great deal, up to and including one’s own life.

This was one of the lessons of the Holocaust, which the Nazis carried out even at the expense of the overall war effort. In 1944, with Russia advancing on a broad front and the Allies landing in Normandy, Adolf Eichmann pulled out all stops to deport more than 400,000 Hungarian Jews to Auschwitz in just two months. The Nazis didn’t even bother to make slaves of most of their prisoners to feed their war machine. Annihilation of the Jews was the higher goal.

Modern Iran is not Nazi Germany, or so Iran’s apologists like to remind us. Then again, how different is the thinking of an Eichmann from that of a Khamenei, who in 2012 told a Friday prayer meeting that Israel was a “cancerous tumor that should be cut and will be cut”?

Whether the Ayatollah Khamenei gets to act on his wishes, as Eichmann did, is another question. Mr. Obama thinks he won’t, because the ayatollah only pursues his Jew-hating hobby “at the margins,” as he told Mr. Goldberg, where it isn’t at the expense of his “self-interest.” Does it occur to Mr. Obama that Mr. Khamenei might operate according to a different set of principles than political or economic self-interest? What if Mr. Khamenei believes that some things in life are, in fact, worth fighting for, the elimination of Zionism above all?

In November 2013 the president said at a fundraising event that he was “not a particularly ideological person.” Maybe Mr. Obama doesn’t understand the compelling power of ideology. Or maybe he doesn’t know himself. Either way, the tissue of assumptions on which his Iran diplomacy rests looks thinner all the time.

Write to bstephens@wsj.com