What is the JCPOA, the deal meant to restrict Iran’s nuclear activity?

PRESIDENT BARACK OBAMA called it “the strongest non-proliferation agreement ever negotiated”. President Donald Trump derided it as “one of the worst deals ever”. Now the Joint Comprehensive Plan of Action (JCPOA)—the unwieldy name given to the multinational nuclear deal signed between Iran and six world powers in 2015—is on its death bed. Mr Trump pulled out of the accord in May 2018 and progressively tightened American sanctions. Iran responded by gradually abandoning the deal’s restrictions on nuclear activity. President Joe Biden has said that America is willing to rejoin the deal, but Iran’s hardliners are wary. On November 29th Iranian negotiators will meet the deal’s remaining signatories in Vienna to discuss reviving the deal. But what exactly is the JCPOA, and can it be saved?

In 2002 the world learned of a secret Iranian uranium-enrichment site buried deep underground. Enrichment refers to the process of spinning uranium in centrifuges to obtain its most fissile isotope, U-235, which can be used in low concentrations in power plants and at high concentrations in a bomb. Iran claimed its interest was the former; much of the world suspected the latter. As regional tensions rose over the next decade, the programme expanded. Western powers piled on increasingly draconian sanctions to force Iran to back down. Rumours swirled that Israel might launch preventive air strikes, as it had on an Iraqi reactor in 1981 and a Syrian site in 2007.

After years of painstaking diplomacy, kick-started by secret negotiations in Oman, Iran reached a bargain in 2015 with the permanent five members of the UN Security Council (America, Britain, France, Russia and China) plus Germany and the European Union. It mothballed thousands of centrifuges and deferred the use of faster-spinning ones. It agreed to enrich uranium only to low levels. It poured concrete into the core of its heavy-water reactor at Arak, which produces plutonium as a by-product and might have given Iran a separate path to a bomb. And it agreed to the most stringent inspections regime anywhere in the world. In return, the most onerous sanctions were lifted, providing partial relief for Iran’s battered economy.

The deal’s proponents argued that the restrictions left Iran more than a year away from being able to produce a bomb’s worth of fuel, up from a harrowing few months. A deal was also preferable to a war. And tough inspections would deter Iran from cheating. Hawks in America, Israel and the Gulf states were less satisfied. Iran would be allowed to continue enrichment, they complained, and some restrictions would expire within a decade (though others last 25 years). In the meantime, they argued, Iran would, through the unfreezing of assets, receive tens of billions of dollars that could be funnelled to allied militant groups in the region.

Mr Trump sided with the hawks. A year after withdrawing from the deal he terminated waivers that had allowed some countries to continue buying Iranian oil. Iran responded with a step-by-step suspension of its compliance with the deal. It broke caps on the quantity of enriched uranium, then resumed enrichment at Fordow, a deeply-buried underground site ringed with anti-aircraft guns, and introduced speedier centrifuges. Iran’s “breakout time”—the time it would need to make one bomb’s-worth of highly enriched uranium—has shrunk to about a month, calculates David Albright of the Institute for Science and International Security, a think-tank. American officials put it at “a few months”, and the rollout of a mechanism to deliver it significantly longer.

What hope is there to resuscitate the deal? Iran’s new president, Ebrahim Raisi, shows little enthusiasm for returning to the JCPOA. And even Western diplomats question whether the deal is now worth the effort. The ban it imposed on international arms sales to Iran has already expired. Some suggest creative alternatives. “More-for-more” would release Iran from more sanctions than the original deal in exchange for a longer-term suspension of its nuclear programme. “Less-for-less” would drip-feed some $100bn of assets frozen abroad in return for a rollback of uranium enrichment. If no agreement is reached, the world would be back at square one, with Iran increasing its uranium enrichment and the risk of violent confrontation rising.

Editor’s note (November 23rd 2021): A version of this article was published previously.

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