Ayatollah Ali Khamenei meets with teachers and education officials in Tehran, May 11.

Photo: Iranian Supreme Leader's Office/Zuma Press

The European Union’s envoy charged with reviving Barack Obama’s nuclear deal with the Islamic Republic, Enrique Mora, was in Tehran Wednesday in another—some call it last-ditch—effort to get the clerical regime to come to terms.

During the past 16 months of negotiations—many of them “proximity talks,” with negotiators in separate rooms—Washington reportedly granted Tehran numerous technical accommodations and massive sanctions relief. The two sides apparently overcame Vladimir Putin’s 11th-hour effort to use such relief as a means to void sanctions against Russia. Washington and Tehran likely have agreed, as they did in 2015, to ignore the International Atomic Energy Agency’s questions about Iran’s undeclared manipulated uranium—a prerequisite for a bomb.

But they haven’t surmounted the listing of the Islamic Revolutionary Guards Corps on Washington’s roster of foreign terrorist organizations. Iran’s foreign minister briefly suggested the guards should take one for the team since a new deal would lift the big sanctions on oil—what really matters. The Biden administration has tried unsuccessfully to get Iran’s Supreme Leader Ali Khamenei to trade, offering to revoke the designation for a mere public promise that the Revolutionary Guard Corps won’t engage in further terrorism against Americans.

But the mood in Tehran is triumphal. The Islamic Republic has survived severe sanctions, widespread and violent antiregime demonstrations, the targeted killing of its officials and scientists, nuclear sabotage, a costly war in Syria, anti-Iranian unrest in Iraq, and a grossly mismanaged pandemic that broke the country’s healthcare system. The supreme leader and his minions love repeating the sentiments of Democratic Party luminaries about the failure of Donald Trump’s “maximum pressure” campaign. The early revolutionary slogan “America can’t do a damn thing” once more echoes in Friday prayers.

Until recently, Mr. Khamenei had to battle Iranian presidents asserting their own agenda. Akbar Hashemi-Rafsanjani (1989-97), who made Mr. Khamenei supreme leader in 1989, always wanted to do everything his way. Mohammad Khatami (1997-2005) sought liberal reforms, Mahmoud Ahmadinejad (2005-13) economic justice, and Hassan Rouhani (2013-21) global engagement and foreign investment.

It’s different now. A year into his tenure, Ebrahim Raisi, a political nonentity, limits himself to speeches on good governance. In practice, the office of the supreme leader has fully subsumed the presidency. The theocracy has shed any pretense of internal debate—a centuries-old tradition within the religious schools—in favor of a modern Middle Eastern dictatorship inextricably wedded to an increasingly harsh Islamist creed.

American politicians, mesmerized by economics, often think of foreign policy as a corporate transaction. Mr. Khamenei is neither impressed by sanctions nor enticed by financial rewards. He recently said, “In the economic area, indicators are not good . . . but the economy is not the only criterion for power, progress and success.” Mr. Khamenei is planning less to expand Iran’s economy than to insulate it from global markets ruled by the West.

By relying on internal resources and trade with China, the Islamic Republic may become poorer, but it will be independent. Signs of national strength, in Mr. Khamenei’s telling, are the revolution’s expansion abroad, spiritual vitality and mastery of nuclear science. As Ali Motahari, a pragmatic hard-liner from a renowned clerical family, recently made clear, the development of a bomb would allow Iran to intimidate its enemies more effectively. It is the most assured path to regional predominance on the cheap—Iranian-subsidized Arab Shiite militias and the nuke make an excellent, relatively inexpensive combination for destabilizing the Middle East. Mr. Khamenei, who despite his supposed “fatwa” against the bomb approved nuclear weaponization in the 1990s, won’t trade away these accomplishments to Americans brandishing carrots.

The war in Ukraine has paradoxically reinforced the Islamic Republic’s paranoia. Iran’s diplomats ritualistically support Russia while calling for a cease-fire. Yet in the hard-line Iranian echo chamber, the war is another indication of the cost of trusting America. In this conspiracy theory, Washington deliberately made Ukraine believe that it could be part of the West, dangling before it membership in the North Atlantic Treaty Organization. That U.S. ruse was meant to provoke a Russian invasion. Ukraine is simply another American plot to weaken Russia and galvanize Europe against Mr. Putin.

“It was the U.S. that dragged Ukraine to this point,” the supreme leader opined, “naturally, interfering in . . . [its] domestic affairs . . ., organizing rallies against governments, launching velvet revolutions and color coups d’état.” Mr. Khamenei, who kept a keen eye on the crack-up of the Soviet empire, likely has made a connection between Kyiv’s decision to give up its nuclear weapons in 1994 and Russia’s invasions later.

Arms control for the supreme leader was never about rejoining the community of nations, which he describes as Western-dominated. Initially it was an experiment, giving Mr. Rouhani a chance to show that Iran could be richer and endowed with a massive, sanctions-free, weapons-capable nuclear program. Now it’s an occasion for Americans to plead with Iran’s envoys and offer supplications. The proximity talks are themselves an exercise in American humiliation, since U.S. diplomats aren’t allowed to meet their Iranian counterparts.

For Mr. Khamenei, the indispensable next step for Mr. Biden is clear: Recognize the Revolutionary Guards, who helped to wreck Syria, colonize Lebanon, and maul America in Iraq, as a legitimate national army. If the American president refuses to do so, arms control is dead. This isn’t a problem in Tehran. It may not be a problem in Washington. If the administration allows the status quo to continue—no deal, never-dead diplomacy, restrained sanctions enforcement, no threat of war, increasing hope that Mr. Khamenei’s “nuclear fatwa” is real—then Tehran’s frequent mocking of America as a former Middle Eastern power plays on fact, not fiction.

Mr. Gerecht, a former Iranian targets officer in the CIA, is a senior fellow at the Foundation for Defense of Democracies. Mr. Takeyh is a senior fellow at the Council on Foreign Relations.