Iran may keep no more than 300 kilograms of uranium enriched to 3.67 percent. That number, held for 15 years, sits at the center of the Joint Comprehensive Plan of Action, the nuclear agreement Iran reached with the P5+1 (China, France, Germany, Russia, the UK and the US), as the Arms Control Association lays out in its fact sheet. Negotiators concluded the deal on July 14, 2015, and the UN Security Council endorsed it six days later in Resolution 2231.
What Iran gave up
The limits were specific. Iran had to run centrifuges cut down to 5,060 IR-1 machines for 10 years and cap enrichment at 3.67 percent uranium-235 for 15 years, at Natanz only. The Arak reactor needed a new core, and Iran committed never to reprocess spent fuel. Inspectors would watch uranium mines continuously for 25 years and centrifuge facilities for 20.
The International Atomic Energy Agency verifies compliance. On January 16, 2016, Implementation Day, the agency certified Iran’s compliance and sanctions relief took effect. A 35-day dispute mechanism sits behind the deal, and a snapback provision lets sanctions be reinstated for 10 years.
The 2018 exit
In 2018, President Donald Trump pulled the United States out. He argued, the Council on Foreign Relations noted, that the agreement did not rein in Iran’s missile program or its regional influence. Washington put sanctions back on Iran’s banking and oil sectors.
Iran answered in 2019 by exceeding the stockpile limits. It developed advanced centrifuges and restarted heavy water production. By early 2023, UN inspectors reported that Iran had enriched trace amounts of uranium to levels close to weapons grade.
Talks that never settled
Efforts to bring the deal back to life began in April 2021. They went on and off. As of late 2023, the parties remained far apart, split over the designation of the Islamic Revolutionary Guard Corps and over how much further Iran’s program had moved.
The sunset dates
The agreement was built with expiry dates. On October 18, 2023, Transition Day, the UN lifted missile restrictions. October 18, 2025, ten years after Adoption Day, was set as Termination Day, when Resolution 2231 ends.
Sources
- What Is the Iran Nuclear Deal? (Council on Foreign Relations backgrounder)
- The Joint Comprehensive Plan of Action (JCPOA) at a Glance (Arms Control Association)
