Here are some of the changes Washington and Tehran have made in the years since the agreement first went into effect, and the challenges for a return to some version of the accord.
What was the 2015 nuclear deal?
The Joint Comprehensive Plan of Action, or JCPOA, set out a framework for curbing Iran’s development of a nuclear program in exchange for U.S. sanctions relief. Negotiated by a group known as the P5+1 — China, France, Russia, the United Kingdom, Germany and the United States — the deal went into effect in 2016. That’s when Washington began rolling back billions of dollars of banking, oil and other economic sanctions aimed at cutting Iran and its leaders off from international markets. Tehran in turn limited nuclear enrichment and allowed for more international oversight of its facilities and program.
But President Donald Trump strongly opposed the accord, a centerpiece of the Obama administration’s foreign policy, and unilaterally left the deal in 2018. As part of his alternative “maximum pressure” policy, Trump reimposed economic sanctions on Iran and issued some 1,500 additional sanctions, according to Biden officials, that targeted Iran and Iran-linked individuals and companies. Iran said it would remain committed to the deal, yet it also began increasing uranium enrichment and building nuclear know-how beyond the deal’s limits.
By the end of Trump’s term, the gulf of distrust between Iran and the United States was deep. President Biden, however, has pledged to reenter the deal if Iran also returns to compliance. But both sides have yet to agree on what that would look like.
How has the United States turned away from the deal?
Iran has been hit with more sanctions than any other country in the world, with broad U.S. restrictions on its banking system and an oil embargo.
The United States has had sanctions in place against Iran since 1979, but Trump increased them to unprecedented levels.
After leaving the nuclear deal, Washington initially reimposed non-oil sanctions in August 2018, followed in November of that year by sanctions on some 700 Iranian individuals and entities, including 300 designations not in place before the 2015 deal, according to the International Crisis Group.
The United States at first offered waivers to allow some countries to purchase oil from Iran. Six months later, in April 2019, the Trump administration announced an end to the exemptions. Secretary of State Mike Pompeo said at the time that the aim was to cut Iran off from some $50 billion in annual oil revenue.
In the following years, Washington continued to add designations that were not in place during the JCPOA negotiations. Targets included banks, including Iran’s central bank, individuals, such as Iran’s supreme leader, and oil vessels, among other entities. The Trump administration also reduced the number of licenses the U.S. treasury grants to companies for certain medical exports to Iran, exacerbating shortages.
In April 2019, the Trump administration listed Iran’s elite military Revolutionary Guard Corps as a foreign terrorist organization.
In January 2020, the Trump administration targeted Iran’s steel and metal industries, following an Iranian attack on two U.S. bases in Iraq after the U.S. assassination of Iranian general Qasem Soleimani. In May, Trump issued sanctions against Iran’s Interior Ministry for human rights violations during anti-government protests that November.
How has Iran deviated from the deal?
Once the United States backed away from the deal, Iran’s foreign minister said the country would feel free to “pursue industrial-scale enrichment without any restrictions.” Independent monitors have subsequently reported that Iran is stockpiling more uranium than permitted under the joint agreement and enriching it at higher levels than allowed.
To be considered weapons-grade, uranium must be enriched at 90 percent. But the United States and its allies are on high alert for any changes that reduce the “breakout time” — the amount of time it would take Iran to build a nuclear bomb. Some analysts believe that the “breakout time” has now fallen from one year to three months.
The watchdog agency also reported in February that Iran may have stored nuclear materials at three sites that were not declared to international monitors and was refusing to answer questions about those facilities.
Under the terms of the joint agreement, the IAEA is supposed to be able to visit any facilities under short notice to perform “snap inspections.” Last year, however, Iran’s parliament passed a law that allows inspections to take place only at declared nuclear sites.
While there were fears that inspectors might be expelled from the country, that hasn’t transpired. In late February, shortly before the law went into effect, the IAEA announced it had reached a temporary compromise with Iran that would “retain the necessary degree of monitoring and verification work” for the next three months.
In addition, the oversight agency has found evidence that Iran is manufacturing uranium metal, which was banned under the joint accord. Iran claims that it was trying to produce fuel for a nuclear reactor, but other world powers have raised concerns that the substance could form the core of a nuclear bomb.
How might the deal be revived?
The United States can theoretically roll back all pre-2018 sanctions, but Biden is unlikely to lift all the sanctions since imposed — including those that punished human rights abuses or election interference and were not directly tied to the deal.
Ali Vaez, Iran project director with the International Crisis Group, said he expected Biden to issue “meaningful and tangible sanctions relief in line with the JCPOA,” though it could take months to sift through all the Trump-era additions to decide which ones to include.
Thomas Countryman, former acting U.S. undersecretary of state for arms control and international security, said during a call with reporters Monday that “by labeling all kinds of designations, all kinds of sanctions, under different categories,” the Trump administration “intentionally blurred the line between nuclear-related sanctions, which must be lifted under the JCPOA, and all kinds of terrorism and human rights designations under other legislative authority.”
The designation of the Revolutionary Guard as a terrorist group is a change Biden is unlikely to roll back, Vaez said, but in other cases, such as sanctions targeting Iran’s Central Bank, Biden could find more leeway.
Analysts generally agree that most of Iran’s breaches of the accord can be reversed. But what can’t be undone is what the other signatories to the deal have categorized as “irreversible knowledge gain.”
Iran’s foreign minister, Mohammad Javad Zarif, has made clear that the country is willing to return to compliance if the United States lifts all sanctions. He also said in December that Iran wants to see a “good faith” demonstration that the United States would not rejoin the deal only to walk away again.