U.S. Secretary of State John Kerry during a break during the Iran nuclear program talks in Lausanne, April 1, 2015.
Ruben Sprich / Reuters

After the 18-month stretch of tough negotiations following the implementation of the interim agreement (or Joint Comprehensive Plan of Action), the nuclear negotiators are enjoying a well-deserved break from the bargaining table. On April 2, the European Union and Iran issued a brief “understanding” on a political framework for a future nuclear deal between the P5+1 and Iran. More detailed fact sheets unilaterally issued by the United States and Iran bolstered that document. The political framework is an important step toward a comprehensive agreement. For the first time, Iran has tentatively accepted substantial reductions in, and limitations on, its capacity to produce fissile material for nuclear weapons for 10–15 years, along with enhanced monitoring and inspections for up to 25 years. In return for implementing these measures, Iran will receive near-term relief from nuclear-related sanctions imposed by the United States, the European Union, and the United Nations Security Council.

The basic contours of the political framework are solid, but the parties have a lot more work ahead of them if they are to complete a comprehensive agreement by their self-imposed deadline of June 30, 2015. Comparing the U.S. and Iran fact sheets (as translated by the Belfer Center’s Payam Mohseni), here are some of the remaining disputes.

First, what happens to Iran’s existing stockpile of low-enriched uranium?

During the course of earlier negotiations, the United States agreed that Iran could retain 6,000–7,000 IR-1 centrifuges on the understanding that most of Iran’s low-enriched uranium would be shipped abroad for fabrication into fuel for the Bushehr nuclear power reactor, leaving only 300–500 kilograms on Iran’s soil at any time. This formula was necessary to preserve a one-year breakout period—the time required for Iran to produce enough weapons-grade uranium for one bomb (27 kilograms of 90 percent enriched uranium) at its Natanz enrichment facility. In the final days of negotiations, however, Iran pulled back and declared that it had no plans to export its low-enriched uranium.

The issue apparently remains unresolved. According to the U.S. fact sheet, Iran will retain 6,104 IR-1 centrifuges at Natanz, 5,060 of which will continue enriching. The sheet also notes that “Iran has agreed to reduce its current stockpile of 10,000 kg of low-enriched uranium (LEU) to 300 kg of 3.67 percent LEU for 15 years.” Iran’s fact sheet states that “Iran will be able to use the existing enriched stockpile for producing a nuclear fuel center and/or its export to international market in exchange for uranium.” The United States has suggested that any surplus low-enriched uranium in Iran beyond the permitted 300 kilograms should be “diluted”—that is, mixed with depleted uranium and returned to natural uranium. Iran prefers to “convert” the surplus from UF6 (a gas that can be used for further enrichment) to a solid oxide form to supply its efforts to develop an indigenous fuel fabrication facility. Resolving this issue is important because, in theory, Iran could re-convert any remaining low-enriched uranium oxide to UF6 and use it for enrichment, potentially reducing its breakout time below a year.

The second question is what the limits are on enrichment in years 10–15 of the agreement.

According to the U.S. fact sheet, the limits on enrichment to ensure a one-year breakout time will be enforced for ten years. These physical limits include caps on the number of installed and operating IR-1 centrifuges and the stockpile of low-enriched uranium, as well as prohibitions on the construction of additional enrichment facilities, enrichment above 3.67 percent, and enrichment with more advanced centrifuges. After 15 years, all of these physical limits will be removed. Between ten and 15 years, the U.S. fact sheet suggests that some limits will be eased, such as the ban on using advanced centrifuges for enrichment, based on an “enrichment and enrichment R&D plan” specified in the comprehensive agreement. The Iranian fact sheet, however, simply states that “the timeframe of the Comprehensive Plan of Action regarding Iran’s enrichment program will be 10 years,” suggesting that all limits are removed after that point. The final agreement will need to specify constraints on the number and type of centrifuges that can be deployed at Natanz between year ten and year 15, which will determine how much Iran could reduce the breakout timeline below a year after year ten of the agreement.

Third, how will Fordow be converted?

Both sides have agreed that the Fordow enrichment facility will be converted to a research facility, but several details remain to be determined. According to the U.S. fact sheet, Fordow will not be used for enrichment or enrichment research and development for 15 years. In addition, almost two-thirds of Fordow’s existing 3,000 centrifuges and infrastructure will be removed, with the remaining centrifuges not to be used enriching uranium. According to Iran’s fact sheet, “More than 1,000 centrifuges and all related infrastructure in Fordow will be preserved and maintained, out of which two centrifuge cascades will be in operation.” Two cascades equal slightly more than 300 centrifuges. Presumably, Iran intends to keep the remaining nearly 700 centrifuges at Fordow on standby to resume uranium enrichment if the comprehensive agreement fails. It is not clear that the United States has agreed to this arrangement. Both sides do seem to be in agreement that the operating centrifuges at Fordow will be used to produce stable isotopes for industrial or medical uses, but the United States may seek to further specify those isotopes (such as Zinc and Molybdenum) that render the centrifuges unusable for uranium enrichment, while Iran may wish to produce isotopes (such an Xenon) that allow the centrifuges to be reused for uranium in the future.

The fourth question is how enhanced inspections and monitoring will be implemented.

According to the U.S. fact sheet, Iran has agreed to an impressive set of inspection and monitoring measures beyond the IAEA Additional Protocol, including a “procurement channel” to “monitor and approve” Iran’s acquisition of “certain nuclear-related and dual use materials and technology” and a challenge inspection mechanism to allow the IAEA “to investigate suspicious sites or allegations of a covert enrichment facility, conversion facility, centrifuge production facility or yellow cake production facility anywhere in the country.” The U.S. fact sheet also states that “Iran will implement an agreed set of measures to address the IAEA’s concerns regarding the Possible Military Dimensions (PMD) of its program,” referring to past and possibly continuing research on nuclear weapons. The Iranian fact sheet is silent on these additional verification measures, beyond its commitment to implement and eventually ratify the Additional Protocol. Because verification and monitoring is crucial, the final agreement will need to specify the exact procedures and mechanisms for approving procurement and challenge inspections, which will presumably be codified in a new UN Security Council resolution. It also remains to be seen whether Iran will implement measures (to be defined) to satisfy the IAEA’s PMD investigation—something that Iran has largely resisted up to now.

Finally, the two sides must nail down the timing of sanctions relief.

The U.S. fact sheet states that “the U.S. and E.U. nuclear-related sanctions will be suspended after the IAEA has verified that Iran has taken all of its key nuclear-related steps” and that “all past UN Security Council resolutions on the Iran nuclear issue will be lifted simultaneously with the completion, by Iran, of nuclear-related actions addressing all key concerns (enrichment, Fordow, Arak, PMD, and transparency).” Iran’s fact sheet is less clear. In one section, it states that “after implementation of the Comprehensive Plan of Joint Action, all of the UN Security Council resolutions will be revoked and all of the multilateral economic and financial sanctions of the EU and the unilateral ones of the US including financial, banking, insurance, investment, and all related services, including oil, gas, petrochemicals, and automobile industries will be immediately revoked.” Elsewhere, the Iranian fact sheet is more specific: “At the same time as the start of Iran’s nuclear-related implementation work, all of the sanctions will be automatically annulled on a single specified day.”

Clearly, there is a major issue. The United States wants sanctions relief to be dependent on performance, whereas Iran wants immediate relief. Also worth noting is an underlying dispute on the content of the UN Security Council resolution required to implement the comprehensive agreement. The U.S. fact sheet emphasizes that the new resolution will “endorse” the comprehensive agreement and “urge” its implementation, while retaining “important restrictions on conventional arms and ballistic missiles.” In Iran’s version, the resolution should be “binding and executable for all UN member states.” This suggests that Iran will seek to codify sanctions relief in international law, which the United States will oppose for political and constitutional reasons.

None of these remaining issues are insurmountable. Given the progress to date and the interest of all sides in reaching a final agreement, it seems likely that a comprehensive agreement can be achieved. However, hard bargaining is ahead. To get the best deal, the U.S. negotiators should not be driven by the June 30 deadline to complete an agreement. The status quo under the interim agreement—which has frozen or capped most of Iran’s nuclear program while retaining most of the sanctions—gives the United States a strong bargaining position. Tehran needs a deal more than the Washington does. If a further extension of a few months beyond June 30 is necessary to get the details right and resolve the remaining issues to U.S. satisfaction, the American negotiators should be allowed more time. Accordingly, Congress would be wise to stop threatening precipitous sanctions legislation if an agreement is not reached by June 30. Perversely, such threats strengthen Iran’s hand by putting pressure on the U.S. negotiators to make concessions to avoid congressional action that would blow up the talks. Iran is counting on divisions between the administration and Congress (and between the United States and Israel) to get a better deal. Instead, the United States should present a common front and let time work on its side. 

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  • GARY SAMORE is Executive Director for Research at the Belfer Center for Science and International Affairs at the Kennedy School of Government at Harvard University.
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