Updated June 2025
What is the Iran Deal or “Joint Comprehensive Plan of Action” (JCPOA)?
On July 14, 2015, the United States and its international negotiating partners reached an agreement with Iran on its nuclear program: the Joint Comprehensive Plan of Action (JCPOA) or the Iran nuclear deal. The agreement was formally adopted on October 18, 2015, and would only go into effect after Iran completed several initial steps. As a part of the deal, Iran also agreed to implement the Additional Protocol, which is an expanded set of requirements for information and access to assist the International Atomic Energy Agency (IAEA) in its task of confirming that states are using nuclear material for solely peaceful purposes.
The JCPOA was implemented January 16, 2016 after the IAEA reported that Iran had made the necessary changes to its nuclear program and granted the IAEA the access necessary to verify the agreement. In exchange, the United States and other world powers agreed to waive nuclear-related sanctions.
In 2018, the United States unilaterally withdrew from the Iran nuclear deal. Despite periodic attempts to revive the deal since then, Iran accelerated its uranium enrichment, limited inspector access to its nuclear facilities and is now closer to developing a nuclear weapon than before the deal. The demise of the JCPOA brought uncertainty both for the future of nuclear negotiation with Iran and the international community who now lack insight into potential developments in Iran’s nuclear program.
Purpose
The objective of the JCPOA was to constrain Iran’s nuclear program and provide confidence it was not continuing progress toward a nuclear weapon. However, the agreement permitted Iran to keep a comparatively small amount of monitored low-enriched uranium. Thus, the Iran deal did not extinguish all Iranian nuclear activity; rather, it aimed to ensure transparency: if Iran took steps toward weapons capability, the world would know.
Strengths of the JCPOA
The JCPOA verification regime was effective at providing transparency into Iran’s nuclear program, which allowed Iran to raise confidence that it was not producing nuclear weapons. The JCPOA blocked the two paths to accumulate weapons-grade fissile material for a nuclear weapon: enriching uranium-235 to 90% purity or higher and separating plutonium. In fact, the plutonium-related provisions of the JCPOA were of such merit that after the United States’ withdrawal in 2018, the Trump administration issued sanctions waivers for several years, ensuring the United Kingdom and China could continue to modify Iran’s heavy water reactor at the Arak Nuclear Complex without being subject to economic penalties. As originally designed, the Arak reactor could have produced enough plutonium from its spent fuel for one or two nuclear weapons per year, but the JCPOA closed off the plutonium path.
Weaknesses and Criticisms of the JCPOA
One of the main arguments used against the JCPOA was that it allowed Iran to continue enriching uranium and move closer to nuclear capability while remaining technically in compliance. The JCPOA also contained so-called “sunset provisions” on various aspects of the deal such as lifting limits on centrifuges after 10 years or reduced enrichment beyond 3.67% only lasting for 15 years. This led to concerns that the deal would only temporarily delay Iran’s nuclear program while preventing parties from finding a more permanent solution. Additionally, critics worried that lifting sanctions on Iran in return for the JCPOA’s focus on constraining Iran’s nuclear program would diminish the United States’ ability to address other security concerns such as Iran’s missile program or its funding of violent non-state groups in the Middle East.
Collapse of the Iran deal and Possible Return to Compliance
In 2018, the United States unilaterally withdrew from the Iran nuclear deal. Others involved in the deal, particularly its European partners, tried to keep the deal running without the United States, but in 2019 Iran accelerated its uranium enrichment, and the JCPOA further deteriorated. In February 2021, at the direction of its parliament, Iran suspended implementation of the Additional Protocol following almost three years of unilateral maximum pressure sanctions imposed by the United States.
There is still no alternative for the deal despite periodic attempts by China, France, Germany, Russia, the UK, Iran and the United States to revive the JCPOA’s core bargain of sanctions relief for constraints of Iran’s nuclear program.
Iran’s advancing uranium enrichment program remains the key obstacle for diplomats trying to revive the deal. The JCPOA restricted Iran from enriching uranium past 3.67% until 2030, but today, Iran is enriching uranium to a higher purity and its stockpile is increasing. In March 2025, the IAEA reported that Iran increased its stockpile across all levels of enrichment, with an increase in its 60 percent highly enriched uranium from 182 kg in October 2024 to 275 kg in February 2025. Iran is also introducing advanced centrifuges and conducting experiments with uranium metal. As seen from the chart, Iran’s breakout time — the amount of time it would take to produce enough highly enriched fissile material for a nuclear weapon, but not including the time it would take to build a weapon — had been substantially decreased from more than one year during the deal to one week or less as of the IAEA’s November 2024 report. The IAEA also noted that the currently delayed inspection process in Iran would make it difficult to detect any breakout promptly.
In November 2024, Iran permitted the IAEA director general to visit the Natanz and Fordo enrichment plants. Allowing this visit amid tensions was likely a signal from Iran that the easiest access to these facilities is through diplomatic engagement. It also serves as a reminder of the JCPOA’s true benefit — the transparency it provided under the verification regime that allowed Iran the opportunity to build confidence that it was not producing weapons.
Diplomatic Engagement Under the Second Trump Administration
Beginning in April 2025, the Trump Administration re-engaged in a series of talks with Iran over its nuclear program, with Oman serving as the intermediary. As of June 2025, five rounds of talks have taken place. The three main issues under discussion are verification and transparency measures, Iran’s current stockpile of enriched uranium, and the future of Iranian uranium enrichment.
Iran’s ability to enrich uranium reportedly remains the central sticking point. The United States has reportedly proposed a framework that would prohibit enrichment on Iranian soil, advocating instead for a regional consortium model in which civilian enrichment would take place in neighboring countries like the United Arab Emirates or Saudi Arabia under international supervision. Iran has acknowledged receipt of the proposal but criticized it as unbalanced and overly favorable to U.S. and Israeli interests. Iranian officials have said they will formally respond in accordance with national interests but have stated that retaining the right to enrich uranium inside Iran remains a red line. In parallel, Iranian negotiators have reportedly countered with a variation of the regional consortium idea, one that would permit uranium enrichment on Iranian soil under regional and IAEA oversight.
In its confidential report dated May 31, 2025, the IAEA confirmed that Iran now possesses over 400 kg of uranium enriched to 60% purity — a nearly 50% increase since February. The agency also reiterated its inability to resolve longstanding questions about past undeclared nuclear activities due to Iran’s ongoing lack of cooperation, raising concerns that a future agreement would face serious verification challenges unless such issues are addressed upfront.
