Under the deal, Iran will maintain the ability to enrich uranium but only for peaceful purposes. It will keep about a third of its 19,000 centrifuges capable of separating the explosive uranium-235 isotope from uranium ore. It agreed to refine the metal to no more than 5 percent enrichment, the level needed to fuel nuclear power plants. It further pledged to slash its enriched-uranium stockpile to just 4 percent of the current level. These arrangements may last for as many as 15 years. Iran also vowed to limit enrichment to a single facility at Natanz. That’s significant because Israel worries that another site, Fordo, may be impervious to bombing. Under a November 2013 temporary accord, the International Atomic Energy Agency verified that Iran eliminated its known stockpiles of 20 percent-enriched uranium, which can be used to make medical isotopes and to power research reactors but can also be purified to weapons-grade at short notice. Keeping an enrichment capability was important to Iran presumably for reasons of national pride and because enrichment gives Iran the power that comes with being able, as countries such as Japan and Argentina are, to produce fuel for nuclear weapons should it choose to break its commitments. Iran said it would allow inspections by IAEA monitors at a wide variety of facilities and would clear up suspicions of past weapons work. It agreed to redesign its heavy water reactor in Arak so that it does not produce weapons-grade plutonium, material that would provide a second path to nuclear weapons. The U.S. estimates that the agreement extends the time it would take Iran to produce enough fissile material for a bomb from a few months to at least a year. The timing of sanctions relief remains to be worked out.
The agreement marked a breakthrough between the U.S. and Iran 36 years after the Islamic Revolution. Before falling from power, the U.S.-backed Shah Mohammad Reza Pahlavi had planned to build 20 nuclear power reactors with international help. Supply agreements were later revoked. Iranian statements and international contacts with Pakistani scientists prompted the U.S. Central Intelligence Agency to warn in 1992 that the Persian Gulf country could develop a nuclear weapon. While Iran reaffirmed its commitment to the 1968 nuclear Non-Proliferation Treaty, it wanted a “right” to enrich uranium recognized before it made concessions on its program. Few countries were prepared to agree to that during the eight-year presidency of Mahmoud Ahmadinejad, who threatened Israel with destruction. President Hassan Rouhani was elected in 2013 on a pledge to end the economic isolation of the country, which sits on the world’s fourth-largest proven oil reserves.
Israel and critics in the U.S. Congress say Iran can’t be trusted and shouldn’t be permitted to make any fissile material, whether for energy, medicine or bombs. They argue that Iran could be forced to give up its enrichment abilities entirely by the threat of tougher sanctions. Skeptics aren’t satisfied by IAEA verification. They point out that Iran only acknowledged its two main uranium enrichment plants after they were exposed by people outside the country. Supporters of the deal say Iran would never agree to abandon enrichment entirely. U.S. President Barack Obama argued that the pact was tough enough to prevent enrichment to weapons-grade levels. No deal, supporters say, would leave Iran free to make a bomb — or lead to a war aimed at keeping that from happening.
The Reference Shelf
- Bloomberg News published a layman’s guide to the Iran talks, a timeline about the country’s history of deception and a map of major nuclear facilities.
- Carnegie Endowment for International Peace April 2013 report estimating the costs and risks of Iran’s nuclear program.
- Federation of American Scientists overview of Iranian nuclear facilities and video showing how uranium enrichment works.
- The Economist special report on Iran from November 2014.
- The Arms Controls Association website has fact sheets and briefing papers about the talks.