Iran is running out of leverage.
Fundamentally, Tehran seeks leverage to reduce crippling economic and, increasingly, strategic pressure. It wants relief from international and unilateral sanctions that have severely restricted its economic activities, foreclosed investment opportunities, and stalled Iranian growth and development. And it needs time and space to recover from a string of strategic blows that have significantly diminished its standing and influence in the region.
These aims, however, cannot be achieved without settling the nuclear issue. The decades-long tussle over the scope and scale of its nuclear program has been extremely costly for Iran and has significantly limited its freedom of action to pursue other national interests. But more than five years’ worth of failed attempts to fully restore the Iran nuclear deal following U.S. withdrawal and subsequent Iranian violations has severely limited the number of cards Tehran has left to play.
Tehran could, of course, decide to try to build nuclear weapons. Its significant expansion of proliferation-sensitive activities since 2019 means that it has more viable pathways to do so quickly. A decision to proceed with weaponization, however, is highly likely to be detected, all but guaranteeing a military response from Israel and perhaps also the United States—a likely devastating outcome that Iranian leaders have assiduously sought to avoid.
Recent rhetoric suggests Iranian leaders may instead be coalescing around a different tactic to gain bargaining leverage: threatening to withdraw from the Nuclear Non-Proliferation Treaty (NPT). The NPT is the foundation of the global architecture that prohibits the spread of nuclear weapons. Were Iran to defy decades of international efforts to keep it from developing nuclear weapons by leaving this foundational treaty, it would deal a severe blow to the continued political viability of the nuclear nonproliferation regime. Iran may therefore perceive the threat of NPT withdrawal as its best way to gain leverage to achieve its aims.
Counteracting any such withdrawal strategy calls for inventive diplomacy. The United States and others will naturally pursue coercive measures. But success will likely also require positive inducements and actions to clearly enumerate the ways in which staying in the NPT would benefit Iran. The international community must draw on all the leverage at its own disposal to prevent Iranian withdrawal.
Any Cards Left to Play?
Iran has been attempting to gain sufficient leverage without crossing lines that might trigger military strikes, including on its nuclear facilities. Following the U.S. withdrawal from the Iran nuclear deal in 2018, Iran expanded its nuclear program in incremental and increasingly serious ways, ratcheting up from initial breaches on stockpile limits to a resumption of uranium enrichment activities far beyond the limits of the deal, among other proliferation-sensitive activities.
Initially, Tehran aimed to gain negotiation leverage amid a series of attempts to fully restore the agreement. When that failed, it shifted its focus to reaching a nuclear weapons threshold status, from which it could accrue bargaining power through a more technically capable threat to weaponize its nuclear program quickly. Tehran has since tried to capitalize on that status, including by leveraging it for deterrence, and has further tried to advance its bargaining position, including by cozying up to an increasingly receptive Moscow.
But Iran may have overplayed this hand. Its expanded nuclear activities and efforts to limit International Atomic Energy Agency (IAEA) monitoring have, in many ways, made the threat that it could develop nuclear weapons too credible. Rather than afford Tehran a bargaining sweet spot, this expansion has instead made the international community highly skeptical of Iranian claims that its program is entirely peaceful.
As a result, the European parties to the Iran nuclear deal (France, Germany, and the United Kingdom, collectively known as the E3) are seriously contemplating triggering the so-called sanctions snapback mechanism, which would reimpose all the UN Security Council sanctions on Iran that were suspended under the Iran nuclear deal, before that provision expires in October 2025. Separately, the second Trump administration has restored a policy of “maximum pressure,” though, arguably, it would have done so regardless of the state of Iran’s nuclear program. Trump has also threatened to impose secondary sanctions on or even bomb Iran if it does not make a new deal on the nuclear issue.
Meanwhile, the historical “shadow conflict” between Iran and Israel has become increasingly open and direct. Since the Iranian-backed Hamas militia conducted a deadly attack on Israel in October 2023, Israel has undertaken a vast campaign to weaken Iran and its so-called axis of resistance. In addition to waging a war of attrition against Hamas that significantly diminished the group and also devastated Gaza, Israel has targeted other key militia leaders and carried out crippling strikes on Iran’s air-defense systems, exposing and heightening Iran’s military vulnerabilities. Paired with the fall of Bashar al-Assad’s regime in Syria, these developments have only further undermined Iran’s negotiation position by reducing its regional strength and influence as well as its ability to defend against military attacks on its nuclear facilities.
Amid this confluence of events, Iranian officials have been seeking ways to regain lost leverage. Leaders now regularly refer to NPT withdrawal as a national security imperative. To be certain, Iran’s withdrawal might not be a clear indicator of its intent to build nuclear weapons. From a vastly weakened position, Tehran could perceive a threat to leave the treaty while still stopping short of the bomb as one of the stronger cards it has left to play in an effort to gain the leverage it so desperately seeks.
The Stakes
Even if unaccompanied by a decision to actually go nuclear, Iran’s withdrawal from the NPT would have disastrous consequences for efforts to prevent Iranian proliferation and the further spread of nuclear weapons.
The NPT is a critical line of defense against a nuclear-armed Iran. It binds Iran to a commitment not to develop nuclear weapons and requires international safeguards monitoring that provides the international community confidence that Iran is not cheating. In exchange, Iran maintains the right to peaceful uses of nuclear technology. The treaty provides a legal basis, tied to the UN Security Council, for holding Iran accountable to this nonproliferation commitment. And, since the treaty is a nearly universal agreement, the international community has a vested interested in enforcing Iran’s commitment—or else risk a proliferation domino effect in the Middle East.
If Iran develops nuclear weapons, Saudi Arabia has said it will too. Iranian and Saudi proliferation, in turn, could tempt other regional actors to pursue their own programs. Any such arms race would be highly destabilizing in an already volatile region, the consequences of which would be felt around the world.
None of this is to say that the NPT is a perfect instrument. Even as a treaty member, Iran has violated its safeguards and monitoring agreements, including by refusing to resolve outstanding issues and failing to share design information about new nuclear facilities under construction. It has also halted implementation of the Additional Protocol. But the situation would be significantly worse if Iran left the treaty.
Withdrawal would very likely result in a total loss of international access to and oversight of Iran’s nuclear program. Without this monitoring, the international community would have no reliable way to know if Iran were building nuclear weapons. Even if Tehran did set up a safeguards arrangement outside of the NPT framework, the international community would likely find anything short of the full implementation of a comprehensive safeguards agreement, and ideally the Additional Protocol, highly dubious.
This lack of transparency into Iran’s nuclear program would raise the risk of miscalculation and escalation fueled by worst-case assumptions. Israel could, for example, interpret any programmatic development it detects through national surveillance means as a signal of Tehran’s decision to go nuclear. Without a reliable reassurance to say otherwise, it could cite this development as justification for launching an attack on Iran’s nuclear facilities. This would mark a new and exceedingly more dangerous phase of open confrontation in the region.
Iranian withdrawal could also erode regional actors’ confidence that the nonproliferation regime can effectively constrain Tehran’s nuclear ambitions. This disillusionment, in turn, could give others a reason—or excuse—to abandon their own treaty obligations. Not only would this cascade of withdrawals raise the aforementioned risk of a regional nuclear arms race, but it would also fundamentally undermine the NPT and the larger nonproliferation regime it props up.
Bargaining through Withdrawal?
Given the stakes, Tehran may calculate that leveraging the threat of NPT withdrawal is a useful bargaining strategy for achieving its aims.
Iran could, for example, threaten to leave the treaty unless the United States and others restrain further Israeli aggression. It could also try to extract economic relief. Following indications from senior Iranian officials that it would withdraw in the event that sanctions are “snapped back” before October, Iran may interpret the absence of an E3 decision to trigger this mechanism as evidence of the effectiveness of withdrawal threats.
Tehran might employ additional tactics to bolster the efficacy of the withdrawal threat. For instance, it could mount an international campaign to characterize its threat of withdrawal as a valid response to the perceived violation of its right to peaceful nuclear technology, as enshrined in the NPT. It could try to gain support from other states that are sympathetic to arguments that the treaty discriminates against developing countries, which could, in turn, frustrate efforts by the United States, E3, and others to attract additional states to pile pressure on Iran.
The withdrawal bargaining strategy also offers potential avenues for upping the ante. If Tehran does not achieve its aims through the threat of withdrawal alone, it could initiate the actual process of withdrawing by invoking Article X of the NPT. Article X allows a state to withdraw from the treaty if it decides that extraordinary events related to the subject of the treaty have jeopardized its supreme interests. Under this provision, a state must give three months’ notice of its withdrawal. Tehran might assess that this time pressure would force interlocuters to the negotiation table and help extract concessions in return for retracting its withdrawal.
Finally, if still unsatisfied, Iran could complete its withdrawal from the NPT and use the prospect of its return to the treaty as bargaining leverage.
However, actually withdrawing from the treaty might inadvertently decrease whatever bargaining leverage Tehran might have gained. Assuming attempts were made to prevent Iranian withdrawal, the international community would likely have little faith in Tehran to uphold its side of any bargain to return to the treaty. And with no more legal barriers preventing Iran from developing nuclear weapons, states might decide they have no choice but to pursue the most punitive responses to prevent Iranian proliferation.
But even shy of the risks of actually leaving the treaty, there are inherent costs to an NPT withdrawal bargaining strategy. In pursuing such an approach, Iran could expect international blowback in the form of diplomatic, economic, legal, and perhaps even military measures. And if its withdrawal tactics trigger a regional cascade of withdrawals, it could face greater insecurity. A scenario in which Iran’s neighbors leave the treaty to pursue nuclear hedging strategies, for example, would attenuate the perceived security benefits of its threshold status. A scenario in which Iran’s withdrawal precipitates multiple, nuclear-armed states in the region would be even worse for Tehran, tilting the regional balance of power away from any putative Iranian advantage.
Preventing Iranian Withdrawal
Notwithstanding the risks and potentials costs, Iran may nevertheless decide that pursuing this withdrawal strategy is the best option it has left. The United States, E3, and other key players must undertake serious efforts to convince Tehran otherwise.
Punitive measures alone are likely to be insufficient. Iranians have been living through deprivations resulting from international sanctions for years; simply adding to the existing pressure is unlikely to force Iranian leaders to relent. Moreover, the evolving partnership between Moscow and Tehran means Russia is likely to try to shelter Iran from the effects of these measures. China has increasingly indicated a willingness to do the same.
Instead, states seeking to constrain Iran’s nuclear program will need to employ a multifaceted effort that balances any coercive measures with assurances that those measures will not be imposed or will be rescinded if Iran reverses course. Critically, it also should include positive inducements accompanied by strict provisions for Iran’s continued NPT membership and adherence to its nonproliferation obligations, as well as measures that demonstrate how Iran’s NPT membership enhances its security.
Effectively preventing Iranian withdrawal will also require coordination of differentiated actions by various states, depending on their relationships with Iran.
In response to an explicit threat of Iranian withdrawal, one set of coordinated measures could focus on sanctions and their potential relief. France, Germany, and the broader European Union, along with the UK, could offer sanctions relief contingent on clear stipulations, such as: Iran must not follow through on its threat to withdraw and must restate its commitment to the NPT at the highest levels; Iran must fully comply with its IAEA safeguards agreements and perhaps also additional monitoring requirements to prevent Tehran from withholding IAEA inspection access for any additional gains; and Iran must undertake nuclear stopgap measures, such as limiting enrichment activities and refraining from sensitive weaponization research.
In exchange, Europe could work to reduce economic pressure on Iran. But rather than focus on relief from European sanctions that may not provide much in terms of quick, tangible economic effects for Iran, European leaders could work with, say, some Gulf states that have expressed interest in increasing trade with Tehran. Specifically, reducing European restrictions that have limited Iran’s trade and investment in the Gulf could have a greater effect on Tehran’s calculus. To facilitate this engagement and help make this relief even more credible from an Iranian perspective, both European and Gulf leaders could also work to convince Washington to lift some secondary sanctions, which have thwarted much Gulf-Iranian economic engagement.
If Iran does not adhere to the stipulations, including if it invokes Article X, the E3 could trigger the snapback mechanism before it expires in October. This would deal a serious diplomatic blow to Iran, ensuring the nuclear file remains open in the UN Security Council. It would reintroduce severe restrictions on Iran’s economy and, regardless of whether all states enforce those restrictions, complicate Iran’s sanctions evasion efforts. Additionally, and in a scenario where the snapback mechanism has expired, Europeans could work closely with the United States to enforce broader sanctions compliance through secondary sanctions. This could further increase the pressure on Iran’s economy. High-level enforcement could also help create more bottlenecks, making it more difficult for Iran to effectively evade sanctions.
A second set of coordinated measures could focus on the implications of NPT withdrawal for settling the broader nuclear issue peacefully. The United States, for example, could highlight how a lack of transparency into and oversight of Iran’s nuclear program, as discussed above, could make Iran more vulnerable to attacks fueled by worst-case assumptions.
This need not—and should not—take the form of an explicit threat of U.S. military force if Iran withdraws. Rather, U.S. officials could highlight in relevant international forums that Iran’s withdrawal would dramatically increase technical uncertainties about Iran’s nuclear program and activities, making any new negotiation or agreement on the nuclear issue extremely challenging. Its withdrawal could also risk pushing some U.S. leaders to initiate plans and preparations to make the threat of military action in the event of Iranian weaponization more credible. It could also drive Washington to pursue stronger security arrangements with other regional actors, not only as a counter to Iran but also to help prevent a withdrawal and, especially, proliferation cascade.
Importantly, these efforts may have a greater impact on Iran’s calculus if paired with credible reassurances that Washington will exercise restraint if Tehran does not withdraw and ceases its other concerning proliferation-sensitive activities. Washington could start, for example, by making a clear, high-level statement that it would indeed be willing to restrict negotiations to concerns about the weaponization of Iran’s nuclear program for now, which Tehran has signaled is a necessary overture for any future talks.
Meanwhile, the E3 could complement these efforts by highlighting the value of Iran’s NPT membership. They could articulate how staying in the treaty would have a positive assurance effect for Tehran. If Iran fully cooperated with the IAEA, states would have little reason to make worst-case assumptions about its program, thus enhancing Iran’s security in the process. China could communicate a similar message and may be better positioned to help it resonate among Iranian leaders given Beijing’s latest efforts to broker a new nuclear deal and its willingness to back the Iranian position.
Developing countries with notable roles in the NPT regime, such as Brazil and Egypt, could further bolster these efforts to signal broader engagement on the issue and undermine Iranian bargaining tactics. They could clearly articulate that it is Iran’s NPT membership that guarantees its right to peaceful nuclear technology. They could also make clear that in the case of its withdrawal, a lack of international monitoring paired with Iran’s own rhetoric about its technical capacity to build the bomb would significantly weaken any potential appeal to states sympathetic to arguments about discrimination in the NPT.
Conclusion
At a time when the nonproliferation regime is in serious trouble, protecting the NPT against Tehran’s political maneuvering could not be more urgent. Preventing Iranian NPT withdrawal is a crucial step in the larger effort of preventing Iranian weaponization and the further spread of nuclear weapons.
The goal of any such efforts should not be to rescind or circumscribe Iran’s right to withdraw from the NPT. The aim should be to convince Tehran that its best chance of achieving its aims is to remain in the treaty and fully comply with its obligations, rather than bargain away its NPT membership.
Acknowledgments
This article presents key findings from a larger research project aimed at preventing NPT withdrawal. The project was made possible by generous support from the Stanton Foundation. The author sincerely thanks the experts who attended the project workshops as well as other experts and officials who graciously discussed the research topic with her. She is solely responsible for any errors.
Workshop Attendees
- Nobumasa Akiyama, Hitotsubashi University
- Eric Brewer, Nuclear Threat Initiative
- Toby Dalton, Carnegie Endowment for International Peace
- Kelsey Davenport, Arms Control Association
- Darya Dolzikova, Royal United Services Institute
- Christopher Ford, Missouri State University
- Karl Friedhoff, Chicago Council on Global Affairs
- Rebecca Gibbons, University of Southern Maine
- Nicole Grajewski, Carnegie Endowment for International Peace
- Doreen Horschig, Center for Strategic and International Studies
- Kylie Jones, Carnegie Endowment for International Peace
- Chen Kane, James Martin Center for Nonproliferation Studies
- Oliver Meier, European Leadership Network
- Jane Darby Menton, Carnegie Endowment for International Peace
- Ankit Panda, Carnegie Endowment for International Peace
- Mariana Nascimento Plum, Pontifical Catholic University of Rio and the Climate and Sovereignty Center
- Laura Rockwood, Vienna Center for Disarmament and Non-Proliferation
- J. Luis Rodriguez, George Mason University
- Farzan Sabet, Geneva Graduate Institute
- Jay Sarkar, Carnegie Endowment for International Peace
- Tong Zhao, Carnegie Endowment for International Peace
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