The Iran nuclear agreement, formally called the Joint Comprehensive Plan of Action (JCPOA), was a landmark agreement reached in July 2015 between the Islamic Republic of Iran and the P5+1 (the five permanent members of the UN Security Council: China, France, Russia, the United Kingdom and United States, plus Germany). Iran agreed to dismantle much of its nuclear program and allow for more extensive international inspections of its nuclear facilities, in exchange for billions of dollars in nuclear-related sanctions relief.
Specifically, Iran under the JCPOA agreed to not produce either highly enriched uranium or plutonium that could be used in a nuclear weapon. The JCPOA limited the quantity and types of centrifuges Iran can operate, enrichment levels, and the size of Iran’s enriched uranium stockpiles. As a result, Iran’s “breakout time”—the time to enrich enough uranium for a nuclear weapon—was extended to at least one full calendar year under the JCPOA. Iran also agreed to a comprehensive and unprecedented inspections regime that included 24 hour video monitoring and regular inspections of its nuclear facilities by the International Atomic Energy Agency (IAEA) to ensure Iran could not conduct the necessary covert work to achieve a nuclear weapon.
While it held off from major action for several months after President Trump withdrew from the JCPOA in May 2018, Iran eventually began to expand its uranium enrichment beyond the levels allowed by the JCPOA, stockpiling more low-enriched uranium than was permitted. In 2021, Iran further breached the limits of the JCPOA by stockpiling highly enriched uranium. It also expanded its nuclear facilities, installing advanced uranium enrichment centrifuges, which decreases the amount of time it would take for Iran to enrich the uranium it already possesses up to weapons-grade. In 2021, Iran also halted the intrusive verification measures required by the JCPOA, which had given the IAEA stricter oversight of its nuclear facilities.
As a result of these changes, Iran’s breakout time has decreased from one year under the JCPOA, to less than two weeks. Iran could also produce the nuclear fuel needed for 5-6 bombs in this two week period, due to the amount of uranium it has on hand (though experts say construction of an actual weapon with that material would take several months or longer, and would be very hard to detect). In addition, while the IAEA still has some ability to conduct oversight, without the intrusive inspection regime mandated by the JCPOA it is more challenging for the international community to closely monitor Iran’s nuclear activities.
President Trump has repeatedly expressed interest in negotiating a new deal with Iran. In February 2025, Trump announced that he was reimposing his “maximum pressure” campaign of sanctions and other isolating measures on Iran – though in reality he has not meaningfully expanded beyond the sanctions that were already being imposed by the Biden administration, while calling for nuclear talks to begin “immediately” and expressing a preference for a “Verified Nuclear Peace Agreement.” In March 2025, Trump confirmed that he sent a “tough” letter to Iranian leader Ayatollah Khamenei, proposing a new deal and a two-month deadline to achieve it. He also threatened to bomb Iran if a new nuclear deal is not reached, claiming that the US is “down to the final moments” with Iran. Iran responded agreeing to negotiations on March 28.
As of April, the United States and Iran have begun negotiations on a new nuclear deal, mostly dealing indirectly through the Omanis as an intermediary. Both sides have characterized the negotiations as productive, and technical-level talks will be held in the coming days to discuss the contours of a potential agreement.
Iran has repeatedly rejected maximalist demands for a deal that prevents them from conducting any nuclear enrichment—the so-called “Libya model,” referred to as such because Libya completely dismantled its nuclear program under the leadership of Muammar Gaddafi. While some in the Trump Administration, including Secretary of State Rubio and National Security Advisor Waltz, have called for such a deal, others—including Special Envoy Witkoff—have suggested capping enrichment at 3.67% (as the JCPOA did) would be sufficient. President Trump and his State Department spokesperson have both reiterated repeatedly that the “red line” for President Trump is not zero enrichment, but rather “that Iran will not have a nuclear weapon.”
UN resolution 2231, which ratified the JCPOA, included a “snapback” mechanism, which allows any of the five permanent members (P5) of the UN Security Council, as well as Germany, to unilaterally trigger the reimposition of all UN sanctions on Iran if it breaches the agreement. While Iran has been in violation of the deal, snapback sanctions have not been invoked because the Security Council members have been in the process of trying to negotiate a new deal.
However, this snapback mechanism itself expires in October 2025. After this date, restoring UN sanctions would require a new Security Council resolution, which could be vetoed by Russia or China. If there is no progress toward a new nuclear deal before October, the E3 (Great Britain, France, and Germany) will likely invoke snapback sanctions in the late summer or September as a last-ditch attempt to try and get Iran to the negotiating table, as after October this tool will no longer be available.
Iran has threatened to respond to snapback sanctions by withdrawing from the Nonproliferation Treaty (NPT) which it has been a party to since the treaty came into force in 1970. Withdrawing from the NPT would mean Iran would no longer be bound by an international agreement not to develop nuclear weapons and the end of Iranian cooperation with IAEA inspectors. The risk of military strikes against Iran’s nuclear program, and associated military escalation, would also increase substantially, risking another costly war in the Middle East.
An effective nuclear deal with Iran must significantly increase monitoring, limit uranium enrichment, and verifiably ban activities related to weaponization. The agreement should provide IAEA inspectors with access to all of Iran’s nuclear facilities. Ideally, an agreement would also include Iran ratifying the IAEA’s “additional protocol” which allows enhanced inspections and expanded inspection sites.
Restrictions on enrichment should address three factors: enrichment levels, the amount stockpiled at each enrichment level, and centrifuges (both the number and type they possess). While Iran may not be willing to return to the levels mandated under the JCPOA (due to technological advances, mistrust after the initial US withdrawal and a desire to maintain leverage if the US withdraws again), reducing enrichment capacity through the combination of these three dimensions can still produce enrichment levels satisfactory to ensure Iran cannot develop a nuclear weapon while an agreement is in force.
Finally, a ban on weaponization could be enforced through a ban on activities that are required for developing the physical core of a bomb, besides uranium enrichment. There must be intrusive inspections available to verify Iran is not conducting this work. Together, these tools would provide the international community with assurance that Iran is not building a nuclear weapon and that any attempt to divert material and do so could be quickly detected and addressed.
Insisting on a permanent dismantling of Iran’s nuclear program is a recipe for failure given that the program has become a major point of national pride, it has some civilian purposes, and eliminating it altogether is not politically realistic. Iran also has strong incentives not to agree to full dismantling of their nuclear program in case the US reneges on their end of the bargain and once again withdraws from the nuclear deal. Fully dismantling their nuclear program removes a key deterrent tool for Iran against potential attack.
A “zero enrichment” deal is also not necessary to achieve nonproliferation goals and prevent Iran from getting a nuclear weapon. Limits on enrichment and rigorous international inspections are enough to prevent Iran from weaponizing its uranium and ensure transparency. The JCPOA was not a zero enrichment deal, and was effective while it was in place.
Recent US intelligence reports seen by the Washington Post indicate that a military strike on Iran’s nuclear facilities would, at best, set Iran’s progress to a nuclear weapon back by only a matter of months. Iran could quickly rebuild its nuclear facilities and capabilities even if destroyed. According to the Washington Institute for Near East Policy, “a preventive attack is unlikely to be a solitary event, but rather the opening round of a long campaign.”
In addition, over the past several years while there has not been a nuclear deal in place, Iran’s nuclear experts have developed considerable knowledge and technical expertise about how to build a nuclear weapon that cannot be bombed or assassinated away. Finally, US intelligence indicates that any attack would also incentivize Iran to pursue weapons-grade enrichment of uranium, and thus have a counterproductive effect.
In recent years, Israeli security officials have increasingly backed a new deal to prevent Iran from getting a nuclear weapon, despite Prime Minister Netanyahu’s politicization of the issue and opposition to diplomacy. Preventing Iran from getting a nuclear weapon is one of Israel’s chief security concerns, and at the time that President Trump withdrew, the JCPOA was working as intended to achieve that goal. Diplomacy has a proven and effective track record on this issue while Israeli military officials say that their campaigns of sabotage and espionage have had little success in impeding Iran’s nuclear progress.
Additionally, any military action to set back Iran’s nuclear program comes with the risk of military escalation that could spiral out of control. While Israel has proven capable with American support of defending against Iranian missile attacks over the past year, all it takes is one missile landing in Israel and causing significant damage or civilian fatalities to escalate the situation. And, with Israel already stretched thin and occupied in Gaza, the West Bank, and Syria, it doesn’t need another major war.
Members on both sides of the aisle can do the following to ensure the US can reach a new nuclear agreement:
Under the Iran Nuclear Agreement Review Act of 2015, or INARA (P.L. 114-17.), Congress has the opportunity to review any comprehensive agreement with Iran. After reaching an agreement, the President must transmit its text and other key materials on the deal to relevant congressional committees and the majority and minority leaders. Congress then has 30 days (or 60 days, if the 30-day period would overlap with the August congressional recess) to review the deal and can pass a joint resolution of approval or disapproval on the deal. During this review period, the President cannot provide Iran with any sanctions relief. If Congress takes no action, or passes a joint resolution of approval, the deal goes into effect. If a joint resolution of disapproval passes Congress and is then enacted, the President cannot provide Iran with any sanctions relief, preventing the US from upholding its end of a deal involving such relief. The President has the power to veto such a resolution, which could still be enacted through a congressional override. This means that so long as the President can be sure that at least one third of one chamber —plus one additional lawmaker from that chamber—will support a deal, he will not be prevented from implementing it by congressional action under INARA.