Iran’s Nuclear Program

By | Updated Feb 3, 2017 7:34 PM UTC

Iran’s nuclear capabilities have been the subject of global hand-wringing for more than two decades. While Iran’s leaders long insisted the country was not building nuclear weapons, its enrichment of uranium and history of deception created deep mistrust. After more than two years of negotiations and threats to bomb the country’s facilities, Iran and world powers agreed in 2015 to settle the dispute. The deal set limits on the Islamic Republic’s nuclear work in exchange for relief from economic sanctions that crimped oil exports and hobbled its economy. However, U.S. President Donald Trump’s opposition to the agreement  raises the risk that it will fall apart.

The Situation

During his campaign, Trump and his spokespeople said he would dismantle or renegotiate a deal that he argued would “give” Iran nuclear weapons. Changing its terms would require the cooperation of Iran and the other signatories: China, France, Russia, Germany, the U.K. and the European Union. But the U.S., under Trump, could upend the agreement on its own by imposing new sanctions. Under the deal, Iran maintains the ability to enrich uranium for peaceful purposes. It retains about 5,000 centrifuges capable of separating the uranium-235 isotope from uranium ore. For 15 years, it agreed to refine the metal to no more than 3.7 percent enrichment, the level needed to fuel nuclear power plants, and pledged to limit its enriched-uranium stockpile to 300 kilograms, 3 percent of its stores in May 2015. Before the deal was struck, the International Atomic Energy Agency had verified that Iran eliminated its stockpile of 20 percent-enriched uranium, which can be used to make medical isotopes and to power research reactors but could also be purified to weapons-grade at short notice. U.S. officials estimated that the agreement extended the time it would take Iran to produce enough fissile material for a bomb from a few months to a year. IAEA assessments since the deal took effect found Iran sticking to its obligations. In October, it slightly surpassed a limit on its stockpiles of heavy water, which is used in medical imaging and can also fuel reactors that produce plutonium, a weapons material. But it addressed that within weeks by shipping the surplus to Oman.

Iran Abides by Enrichment Limits -- Production and stores of enriched uranium, quarterly data -- QuickTake -- Iran's Nuclear Program
Source: International Atomic Energy Agency

The Background

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 the country’s “right” to enrich uranium recognized before it made concessions on its program. Few countries were prepared to do that during the eight-year presidency of Mahmoud Ahmadinejad, who threatened Israel with destruction. The breakthrough came after more moderate President Hassan Rouhani was elected in 2013.

The Argument

Middle East powers including Israel and Saudi Arabia have criticized the agreement, saying it empowers Iran’s theocratic regime to the detriment of regional security. Critics in the U.S. Congress say Iran can’t be trusted to make any fissile material, whether for energy, medicine or bombs. 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. Trump said during the campaign that the U.S. should force Iran to accept tougher terms. Supporters of the deal say Iran would never agree to abandon enrichment entirely and that a decade’s worth of sanctions failed to stop it from building enrichment capacity. Keeping an enrichment capability was important to Iran, presumably for reasons of national pride. Like other enriching countries such as Argentina, Brazil, Japan and South Africa, the technology gives Iran the ability to pursue nuclear weapons should it choose to break its commitments. Defending the agreement, Trump’s predecessor, Barack Obama, has said that it prevented another war in the Middle East. Without a deal, supporters say, Iran would have been left free to pursue its nuclear ambitions unchecked by world powers and without the pact's onerous inspections.

The Reference Shelf

  • Text of the July 2015 agreement and a New York Times graphic on the outcome.
  • 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.
  • Council on Foreign Relations Web page on the Iran Nuclear talks.
  • 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.

First published Oct. 14, 2013

To contact the writer of this QuickTake:
Jonathan Tirone in Vienna at

To contact the editor responsible for this QuickTake:
Leah Harrison at