LONDON — The title of the interim agreement the United States and its negotiating partners reached Sunday with Iran to freeze much of its nuclear program is deceptively simple.
But a close reading of the four-page, footnote-laden text of the “Joint Plan of Action” makes it clear that the most formidable diplomatic and technical challenges lie ahead.
“Now the difficult part starts,” said Olli Heinonen, former deputy director general of the International Atomic Energy Agency.
From the start, Obama administration officials described the initial agreement the world powers have now secured as a holding action that would keep the Iranian nuclear program in check for six months, so that international negotiators would have time to pursue a more comprehensive agreement.
But the two sides were able to come to terms on that initial agreement precisely because it did not foreclose their options and required steps that, for the most part, are reversible.
The interim accord, for example, allows Iran to preserve most of its nuclear infrastructure, including the capabilities it would need to develop a nuclear device. The United States, for its part, would retain the core oil and banking sanctions it has imposed.
Negotiating a comprehensive agreement would require much tougher choices by each side. And although the initial agreement sought to sketch out the parameters of a follow-on accord, it did so in only the vaguest terms.
Would the follow-on agreement last for five years, 10 years or even more? The comprehensive agreement that is to be negotiated will not be open-ended, and there appears to be no meeting of the minds on how many years it would be in effect.
“The terms of the comprehensive agreement have yet to be defined, but it is suggested that that agreement will itself have an expiration date,” said Ray Takeyh, a former senior adviser on Iran at the State Department and a senior fellow at the Council on Foreign Relations.
“It would be good if the comprehensive agreement was more final,” Takeyh said.
Enrichment remains another thorny issue. The Obama administration has made clear that it is not prepared to concede upfront that Iran has a “right” to enrich uranium.
But the interim agreement makes clear that a follow-on agreement would provide for a “mutually defined enrichment program with practical limits and transparency.”
So the question is not whether the Obama administration is prepared to allow Iran to continue enriching uranium but rather what constraints the United States and its negotiating partners will insist on in return and how large an Iranian enrichment program they are willing to tolerate.
The interim accord makes clear that such an enrichment must be consistent with “practical needs,” and Iran and the United States are likely to have very different ideas of what those requirements would be.
“This, of course, will be one of the central issues in the negotiations for a comprehensive agreement,” said Gary Samore, who served as senior aide on nonproliferation issues on the National Security Council during the Obama administration and is now president of United Against Nuclear Iran, an organization that urges that strong sanctions be imposed on Iran until it further restricts its nuclear efforts.
The negotiators will face other difficult questions in pursuing a comprehensive agreement.
“Will the Fordow enrichment be shutdown? Will the Arak reactor be shut down or converted into a light water reactor?” asked David Albright, president of the Institute for Science and International Security.
The interim deal, Albright added, “did not do enough to narrow down the limitations” that will be in a final deal.
With such a formidable array of issues, negotiators left open the possibility that the initial agreement, which is to last for six months, may need to be extended. Or as the text of the interim agreement states, it is “renewable by mutual consent.”
If a more comprehensive agreement is not reached and an interim accord is extended, Iran will still be able to make a dash for a bomb.
But the United States would have somewhat more warning time of such a “breakout” because of increased verification, constraints on Iran's installation of new centrifuges, the requirement that Iran convert its existing stock of uranium that has been enriched to 20 percent to a less usable form, and the cap on Iran's stockpile of 5 percent enriched uranium, among other measures.
Just how much longer it would take Iran to produce sufficient weapons-grade uranium for a bomb under such constraints is a matter for experts to debate.
Albright estimates that the breakout time would increase by several weeks or perhaps close to a month.
“This may seem a small time,” Albright said. But with international monitors daily checking films at the Natanz and Fordow enrichment facilities, the increase “would be significant.”
For their part, Obama administration officials acknowledge that any major breakthrough in ratcheting back Iran's nuclear program will require negotiating the follow-on accord.
“Now the really hard part begins,” Kerry said Sunday before a meeting here with William Hague, the British foreign secretary. “That is the effort to get the comprehensive agreement, which would require enormous steps in terms of verification, transparency and accountability.”
He added: “We know this: We will start today, literally, to continue the efforts out of Geneva and to press forward.”
Agreement's key points and why they matter
Halting uranium enrichment above 5 percent
This would keep Iran's enrichment level well below the threshold needed for weapons-grade material, which is more than 90 percent enrichment. Uranium enriched to 5 percent is adequate to make fuel for Iran's lone energy-producing reactor in Bushehr on the Persian Gulf coast. For Iran, the ability to keep its enrichment program is a critical issue. Iran's leaders insist on keeping self-sufficiency over the entire nuclear cycle from mining uranium to making nuclear fuel.
'Neutralizing' Iran's stockpile of 20 percent enriched uranium
This level of enrichment is within several steps of reaching weapons grade. Eliminating the stockpile eases Western concerns that Iran possibly could move quickly toward a nuclear weapon. Iran could either convert the 20 percent uranium into reactor-ready fuel, which effectively blocks it from further enrichment. Or Iran could dilute the material to levels below 5 percent enrichment. Iranian officials have said the country has a sufficient stockpile of 20 percent enriched uranium for long-term operations of its research reactor, which runs at the higher-level uranium and produces isotopes for medical treatments and other uses. Allowing Iran to use the stockpile for domestic purposes is an important political takeaway for Tehran. Iranian leaders had balked at demands to ship the stockpile out of the country.
No new centrifuges
This effectively freezes Iran's enrichment capacities for the next six months. Centrifuges are used to turn concentrated uranium into nuclear fuel. Iran, however, is allowed to keep its two main enrichment facilities in operation. Iran's government, which negotiated the deal with world powers in Geneva, would have faced huge backlash from hard-liners at home if either of the labs were forced to shut down.
Suspending work at Arak reactor
The planned Arak reactor in central Iran is a “heavy water” plant, which means it uses a molecular variant of water as a coolant and can run on non-enriched uranium. It also produces a higher degree of plutonium byproduct, which could be extracted and potentially used in weapons production. Iran's agreement not to build a plutonium reprocessing facility deals directly with the weapons program concerns. It also could clear the way for future agreements to resume work on the reactor.
Iran's pledge to address U.N. concerns, including Parchin military base
The specific mention of the Parchin military base near Tehran touches on a long-standing impasse between Iran and the U.N.'s nuclear watchdog organization, the International Atomic Energy Agency. U.N. inspectors want to revisit the site to investigate suspicions of past explosive tests that could have applications in nuclear bomb designs. Iran denies the claim. Iran has said further inspections are possible, but it also wanted to impose limits on public disclosures by the U.N. agency.