Better in their words…

The clerical regime’s atomic ambitions will continue to progress rapidly because the U.S. administration has no intention of trying to rescind what President Obama’s nuclear deal granted: the development of high-yield, easily hidden centrifuges, the key to an unstoppable bomb program. The Islamic Republic has displayed an uncanny ability to advance its aspirations and eviscerate American red lines with impunity.

The theocracy’s nuclear diplomacy succeeds precisely because it seeks no agreement. The mullahs understand things their interlocutors don’t. The U.S. and Israel have repeatedly chosen not to disable Iran’s nuclear program by force, undermining the regime’s fear of attack and allowing the supreme leader, Ali Khamenei, more maneuvering room. All U.S. administrations have sincerely, at times desperately, wanted an accord. The United Nations and the International Atomic Energy Agency censure the Islamic Republic, and the regime ignores them. If Tehran pretends to be interested in diplomacy, Washington, always fearful of another war in the Middle East, makes more concessions.

The achievements of this diplomatic stratagem are extraordinary. Washington and the Europeans once insisted that the Islamic Republic couldn’t have a domestic enrichment capacity. This was a sensible precaution. The infrastructure required to enrich uranium for nuclear power is the same as what is needed to make a bomb. The process is costly, and most nations that use civilian nuclear power import refined uranium.

Yet today U.S. and European officials, and many nuclear experts, pooh-pooh the idea that Iran should forgo indigenous enrichment. The Joint Comprehensive Plan of Action, the nuclear deal Mr. Obama struck and President Trump abandoned, has become canonical among Democrats. It specifies not only that Iran has the right to enrich but that its enrichment capability can become industrialized. The clerical regime obtained this permissive accord by merely showing up at various conclaves and holding firm. American officials fulminated, threatened, bickered among themselves and eventually capitulated.

The Biden administration isn’t diverging from Mr. Obama’s path. A well-timed Israeli leak shows the White House is considering an interim arrangement whereby Iran would cease some of its activities in exchange for sanctions relief. It won’t be long before Washington deludes itself into believing that a threshold capability will satisfy Iran, that it can be an Islamist version of Japan—inches away from developing a bomb but with no intention to take the next step.

The ascendance of the hard-line Ibrahim Raisi to the presidency altered the economics of arms control. He subscribes to Mr. Khamenei’s “economy of resistance,” the notion that Iran can meet its needs by relying on its internal market and trade with China and neighboring states. In this view, segregation from the global economy is virtuous, wise and courageous. Unlike former President Hassan Rouhani, the new crew isn’t looking for Western commerce as a means of rejuvenating the economy and the revolution. There appears to be little concern among Mr. Khamenei’s ruling elite that this scheme will lead to poverty and another lost generation.

Even more than Mr. Raisi, Mr. Trump accelerated history. According to Mr. Obama’s blueprint, we were going to see a nuclear Iran and a much richer clerical regime. Freed from sanctions, the ruling clergy and the Islamic Revolutionary Guards would have had time to build up their armed forces, as well as the nuclear-weapons program. Thinking that renewed and improved sanctions would give him a “good” nuclear deal (always a dubious proposition), Mr. Trump collapsed 15 years of Western diplomacy and the JCPOA’s envisioned decade of sun-setting restrictions into clear and irrevocable choices.

Mr. Biden can’t turn back the clock. Diplomacy and extortion—the two are synonymous for the Islamic Republic—may have had their day. Mr. Khamenei is going to make the president pony up a huge amount of money for the fleeting relief of his nuclear anxiety—assuming the supreme leader still even wants to play such games with the U.S. For Mr. Biden, the only question is whether he wants to endure this humiliation in return for so little.

Mr. Gerecht, a former Iranian-targets officer in the Central Intelligence Agency, is a senior fellow at the Foundation for Defense of Democracies. Mr. Takeyh, the author of “The Last Shah,” is a senior fellow at the Council on Foreign Relations.