Preserving Space for a Nuclear Deal with Iran in 2025

Volume 16, Issue 5  
Dec. 18, 2024

In the wake of the November 2024 U.S. elections, Iranian President Masoud Pezeshkian continues to express support for nuclear talks with the United States to address international concerns about Iran's advancing nuclear activities. However, his administration’s recent efforts to ramp up its uranium enrichment capacity, ostensibly to build leverage ahead of President-elect Donald Trump’s return to the White House, threatens to derail the prospects for reaching a diplomatic arrangement. Tehran’s recent acceleration of proliferation-sensitive activities increases the risk that the United States or Israel perceive its actions as a step toward weaponization, which could trigger military action or prompt Washington to ratchet up economic and political pressure on Iran even further.

If Pezeshkian and other Iranian leaders are serious about diplomacy, Iran should exercise restraint in the coming months and refrain from further nuclear advances or any reduction in International Atomic Energy Agency (IAEA) access and monitoring. Similarly, the incoming Trump administration should recognize the importance of sending early, consistent signals to Iran that it is interested in quickly starting a negotiating process, with the goal of reaching a deal within the first six months of 2025, and condemn loose talk about preventive military action against Iran.

Iran’s Risky Nuclear Advances

According to a Dec. 6 IAEA report, Iran began feeding 20 percent enriched uranium into two cascades of interconnected IR-6 centrifuges to accelerate 60 percent enriched uranium at the Fordow Fuel Enrichment Plant. Iran had been producing 60 percent material with these machines, but it was using 5 percent enriched uranium as feed. The interconnected design, the use of the more advanced IR-6 centrifuges, and the beginning of the enrichment process with 20 percent material allow Iran to enrich uranium more efficiently. According to the IAEA’s assessment, the change in feed will result in Iran producing approximately 34 kilograms of uranium enriched to 60 percent per month—about seven times the previous monthly production of 4.7 kilograms.

Increasing the stock of 60 percent material will decrease the time it will take for Iran to produce enough weapons-grade uranium for multiple bombs. As this timeframe, known as breakout, drops, proliferation risk increases. Being able to quickly produce enough weapons-grade material for multiple weapons could allow Iran to try to try to breakout by producing and then diverting the 90 percent enriched uranium to multiple covert sites for weaponization before the international community could effectively respond. If Iran were to breakout under this scenario, its ability to rapidly enrich to weapons-grade levels and disperse the material to several undeclared locations would also make it far more challenging for the United States and Israel to disrupt weaponization using military strikes.

In another potential scenario, Iran could divert 60 percent material to a covert facility to continue enrichment to weapons-grade levels. Although Western intelligence agencies have a strong track record of detecting undeclared Iranian nuclear sites, Iran’s experience developing more efficient centrifuges since Trump withdrew the United States from the nuclear deal in 2018 would allow Tehran to develop a covert site with a smaller footprint. The speed at which Iran could enrich from 60 to 90 percent also means that even a short delay in detecting the facility could give Tehran enough time to breakout.

There is also a risk that the rapid accumulation of highly enriched uranium at Fordow and the expanded enrichment capacity is judged to be a sufficient enough proliferation threat that it triggers a kinetic response by Israel or the United States, even if there is no clear evidence that Iran is breaking out or diverting material. The IAEA noted in its Dec. 6 report that Iran had already moved 145 kilograms of 20 percent enriched uranium to Fordow to use as feed for the new enrichment configuration. Moving more 20 percent material to Fordow or storing large quantities of 60 percent material raises legitimate concerns that Iran is accumulating highly-enriched uranium to better position itself for breakout, if the decision is made to do so.

In addition to the expanded stockpiles of highly-enriched uranium present at Fordow, the Dec. 6 IAEA report confirmed that Iran is now operating additional IR-6 centrifuges that were installed, but not previously being fed with uranium. According to the Dec. 6 report, Iran is now producing five percent enriched uranium in two additional cascades of IR-6 machines. An additional six cascades of IR-6s are installed but not yet enriching uranium. This additional, operating enrichment capacity further contributes to the proliferation threat posed by the site.

The IAEA did report that Iran notified the agency of the changes at Fordow. In response, the agency is modifying its safeguards approach in order to take into account the change in enrichment, which should provide additional assurance that any move to weapons-grade levels or large-scale diversion of nuclear materials will be quickly detected. Under Iran’s legally required comprehensive safeguards agreement, the IAEA can adjust its safeguards approach based on the scope of the nuclear materials and activities at a declared facility. Although Iran did not abide by the IAEA’s request that it refrain from ratcheting up enrichment at Fordow until the new safeguards approach was deployed, the IAEA did confirm in a Dec. 13 report that Tehran agreed to “increase the frequency and intensity” of safeguards measures. Iran’s acceptance of the additional safeguards measures is positive, but the increased IAEA presence is insufficient to quell concerns about Iran’s nuclear activities.

In addition to the near-term proliferation risks, Iran’s expansion of enrichment at Fordow could have long-term implications. The IAEA raised concerns in its Dec. 6 report about the manner in which Iran is transferring 20 percent enriched uranium to Fordow. According to the agency, Iran’s use of small cylinders to store the 20 percent enriched uranium “results in more measurement errors.” If the IAEA does encounter challenges in accounting for Iran’s stockpiles of enriched uranium, it could complicate future verification efforts under Iran’s safeguards agreement and any limits imposed by a future deal.

Deteriorating Regional Security

The risk posed by Iran’s rapid acceleration of enrichment to 60 percent is further complicated by the shifting regional security environment. After long denying any interest in nuclear weapons, high-level officials and miltary officers in Tehran have suggested over the past year that the country will rethink its position on nuclear weapons if necessary for the security of the country. Over the past several months, the weakening of Hezbollah, along with the fall of the Assad government in Syria, has setback Iran’s forward defense strategy, which relies on partnering with non-state actors to project influence and counter adversaries in the region. The overthrow of Assad could make it more difficult for Iran to provide military assistance to Hezbollah if the new government reduces or shuts down Iranian access.

Additionally, Iran expended a significant number of missiles in its two direct attacks on Israel in 2024. Although the strikes did not demonstrate the full range of Iran’s missile capabilities and the first, in April 2024, afforded Israel ample warning time to prepare its defenses, Israel was able to largely neutralize the impact of those attacks, with help from the United States and others. Israel’s missile defense and its demonstrated ability to retaliate against Iranian assets, including missile production facilities, may lead Tehran to reassess the value of its conventional ballistic missile force as a deterrent.

The shift in Iranian assessments about the security value of it regional partners and ballistic missiles, as well as repeated calls from some Israeli officials for direct attacks on nuclear sites, could push Tehran toward the assessment that nuclear weapons are necessary for the security of the country and to bridge a perceived security gap.

The Necessity of Swift Diplomatic Action

Despite the increased proliferation risk, a nuclear-armed Iran is not a foregone conclusion. The U.S. intelligence community emphasized in a recent report that the risk of proliferation is growing, but continues to assess that there is no evidence that Iran is undertaking key weaponization-related activities. Furthermore, top Iranian officials continue to reiterate their interest in reaching a nuclear deal with the United States that provides relief from sanctions.

The timeframe for negotiations, however, is short. After Trump takes office, his administration will likely have about 6-7 months to reach a deal and then implement it before October 2025. Absent an agreement by that date, it is highly likely that the United Kingdom or France will reimpose UN sanctions on Iran using the ‘snapback’ mechanism in Resolution 2231, which endorsed the JCPOA in 2015. Unlike passing a new resolution on Iran, the snapback mechanism cannot be vetoed.

In a Dec. 6 letter, the UK, France, and Germany reiterated their willingness to use snapback if necessary to pressure Iran to return to negotiations. Although taking this step would put additional pressure on Iran, it would also complicate the path forward for diplomacy. If Iran responds to the reimposition of sanctions by withdrawing from the nuclear Nonproliferation Treaty (NPT), which it has threatened to do, diplomatic energy will shift to keeping Iran in the NPT during the three-month withdrawal notification period. The risk of military strikes against Iran’s nuclear facilities are even more likely during that time.

Preserving Space for Diplomacy

Despite the urgency of the proliferation threat, diplomatic options to avert a nuclear armed Iran, or a conflict to prevent it, are still available, but time is short and the obstacles to success are numerous. In his final weeks in office, President Joe Biden can and should continue to push back against irresponsible calls from Israeli and U.S. policymakers that now is the time to attack the country’s nuclear program. If Trump is serious about reaching a workable nuclear agreement with Iran, he too should condemn reckless calls for military action against Iran and continue to reiterate his openness to talks. Additionally, he could press his future appointees in his administration to refrain from irresponsible threats and pressure. He should also quickly name a nominee for special envoy to Iran and publicly call for that individual to prepare a realistic strategy for engaging Iran.

Both the Pezeshkian administration and the incoming Trump team should also be using the lead-up to the Jan. 20 inauguration to consider the objectives and agenda for talks. If both sides, for instance, approach negotiations with the mindset of achieving a limited deal that increases monitoring of Iran’s program and blocks the most proliferation-sensitive activities in exchange for sanctions relief, it could help jumpstart negotiations. Considering the relationship between a nuclear deal and the regional security situation would also be advantageous, as Iran is unlikely to agree to a deal that limits its ability to leverage its threshold status for security purposes if a risk of attack on its territory remains.—KELSEY DAVENPORT, director for nonproliferation policy