Ten Years Later Is Not Too Late: The Strategic Premises of a New Nuclear Deal with Iran

With President Donald Trump’s self-imposed deadline for a new nuclear deal with Iran set to expire soon, ominous signs that the US-Iranian talks may be on the verge of collapse are multiplying.[1] Diplomatic failure would trigger an escalation that may end up in a military confrontation involving the United States, Israel and Iran and most likely other regional countries. After ordering the unilateral withdrawal of the United States from the 2015 Joint Comprehensive Plan of Action (JCPOA) during his first term, President Trump would thus preside over a second and possibly definitive collapse of nuclear diplomacy with Iran. The tragic irony is that failure would occur in spite of the fact that, compared to 2015, today’s strategic context offers a stronger foundation for a sustainable agreement.

The foundations of the 2015 deal

The JCPOA, concluded ten years ago between Iran and the E3 (France, Germany and the United Kingdom), China, Russia and the United States, alongside the EU, was more than a technical non-proliferation arrangement.[2] It was a political instrument underpinned by a number of interrelated strategic assumptions.[3]

The agreement sought to re-legitimise Iran’s civilian nuclear programme, thus detaching the Islamic Republic from its status of international pariah, by tying it to rules-based international cooperation. The increased trade with and direct investments from Europe, which the JCPOA would engender, was supposed to facilitate the gradual institutionalisation of diplomatic dialogue with Europe itself and a recalibration of US-Iranian relations, at least on nuclear matters, away from coercive posturing. A further assumption involved Iran’s prospective ability to diversify its external relations: engagement with the West would be layered onto existing partnerships with Russia and China, thereby expanding Tehran’s diplomatic bandwidth.

Despite its ambitious design, the JCPOA was marked by structural weaknesses. The exclusion of Arab Gulf states from both the negotiation process and the political premises of the deal undermined its legitimacy. Arguably more important was the absence of institutionalised mechanisms capable of fostering a durable transformation in US-Iranian relations from antagonism to structured engagement. These weaknesses became particularly evident in 2018 with the Trump Administration’s decision to withdraw from the JCPOA, which not just Israel but Saudi Arabia and the United Arab Emirates openly championed.[4]

The strategic premises of a possible new deal

In the present context, any prospective nuclear agreement rests on a different set of assumptions. First, the Trump Administration has reframed the non-proliferation issue within the broader contours of its ideological and geopolitical rivalry with Iran. The potential agreement is viewed by the US president and his closest aides not solely as a technical arms control instrument but as a strategic lever for long-term détente.[5] Rejecting the notion of permanent enmities, Trump has scornfully dismissed regime change as a failed policy approach and repeatedly expressed hope that (a nuclear-free) Iran could flourish and eventually re-engage with the United States. Trump’s penchant for hyperbole aside, the change of rhetoric compared to the past is striking: when President Obama agreed to the JCPOA in 2015, he felt compelled to present it as a limited non-proliferation deal to shield it from its critics in Israel, the Arab world and the United States itself.[6]

Second, the format of negotiations has shifted from a multilateral to a bilateral framework. Europe, once a central architect of the JCPOA,[7] has seen its role increasingly marginalised, with its residual influence confined largely to the so-called ‘snapback’ mechanism.[8] The latter is a leftover of the JCPOA that allows for the re-activation of UN sanctions on Iran that had been lifted pursuant to the deal. However, activating the snapback would be a one-off, high-stakes move. Tehran has threatened retaliatory steps such as expelling UN nuclear inspectors and escalating its nuclear activities, raising the political and diplomatic costs of this option.[9]

Third, the regional dimension is as central now as it was neglected in 2015, with Saudi Arabia and the Emirates openly backing a nuclear settlement.[10] This shift reflects a recalibration of strategic calculations in Riyadh and Abu Dhabi, driven by the tangible costs of escalating US-Iranian tensions, which have resulted in increased Iranian support for the Houthis in Yemen, sabotage to commercial shipping in the Gulf of Oman and even a direct attack on Saudi oil facilities in 2019. The agreement would be constructed as an instrument of lasting regional stabilisation.

A fourth reinforcing strategic premise underpinning a potential new deal is the preservation of Iran’s international partnerships. A new agreement would be compatible with the set of relations that the Islamic Republic has built over the years, from traditional partners such as Russia and China to emerging groupings like BRICS Plus. At the same, an agreement with the United States would create an expectation regarding Iran’s conduct, signalling to its international partners that Tehran is committed to responsible behaviour.

Political challenges, technical solutions

Despite these revised assumptions, significant challenges persist. The most critical one remains Iran’s expectation that it can retain an autonomous capacity for uranium enrichment, a critical component of any civilian programme that can be diverted to military use by raising the level of enrichment. Just slightly less challenging is finding an agreement on the scope and intrusiveness of the verification regime and the sequencing of sanctions relief. In addition, Iranian trust in US commitments has been significantly eroded by the 2018 withdrawal, making diplomatic recalibration more difficult. The fact that a new deal would occur under the very same president who quit the old one – and who is known for not feeling particularly bound by his own commitments – adds to the climate of mistrust.

While both the United States and Iran have shown unequivocal preference for a diplomatic settlement, five rounds of talks in Muscat and Rome have led to no significant breakthrough. If anything, the distance between the parties seems to have widened. After initially hinting that it was ready to accept a limited Iranian enrichment capacity, the US Administration has gradually sounded more uncompromising on the matter, with Trump making ‘zero enrichment’ sound like a red line.[11]

The US president may well be resorting to a maximalist negotiating tactic to extract greater concessions from Iran than the latter is currently prepared to accept. Washington’s decision to support an E3-tabled resolution to censure Iran at the International Atomic Energy Agency (IAEA) aligns with this strategy. The resolution follows the publication of a critical IAEA report, which not only reaffirmed that Iran had engaged in military nuclear activities up to the early 2000s but also raised serious concerns over the presence of an indefinite (probably small) amount of fissile material in the country that remains unaccounted for.[12] While the resolution does not include an automatic referral of Iran to the UN Security Council, it is a preparatory step toward the potential activation of the snapback mechanism by the E3.[13]

Increased international pressure may, perhaps, incentivise Iran to enhance cooperation with the IAEA, but the viability of renewed nuclear diplomacy hinges on the United States’ willingness to compromise on uranium enrichment. The Trump Administration has tried to strike a middle ground. Under a US bridge proposal, Iran would be allowed to enrich uranium at low levels, but only temporarily. In the meantime, the United States and its partners would develop a comprehensive plan for nuclear reactors in Iran supported by enrichment facilities managed by a regional consortium involving Arab Gulf states.[14] Once the consortium is in place, Iran would be expected to halt domestic uranium enrichment.

The Iranian leadership has invested massive political capital in the nuclear programme and endured decades of external pressure, sanctions, sabotage operations and the assassination of nuclear scientists. It views uranium enrichment as a core technological and industrial achievement that it is not prepared to relinquish. The diplomatic breakthrough that led to the conclusion of the JCPOA was only made possible after the Obama Administration eventually agreed to an Iranian capacity to enrich, albeit under strict (but temporary) limitations and comprehensive monitoring.

The precedent set by the JCPOA shows that zero enrichment is not necessary to build confidence in the peaceful nature of Iran’s nuclear programme. What matters is the presence of technical constraints, rigorous international monitoring and full transparency to prevent diversion of nuclear material for weaponisation.

Central to this is the requirement that Iran’s stockpile of 60 per cent enriched uranium – a level with no plausible civilian application – be either down-blended or exported under stringent international oversight. Future enrichment should be capped at or below the 3.67 per cent ceiling, which is sufficient for nuclear reactors. In addition, any sustainable agreement must re-establish full-spectrum monitoring across the entire nuclear fuel cycle, including research and development sites and locations with possible military dimensions. Finally, Iran should provide a credible and complete account of the origin and fate of uranium particles detected at several undeclared sites.

An interim deal with reciprocal concessions could be reached in order to give the negotiators time (at a minimum six to ten months) to agree upon the details, a long and complicated process. The E3 could obtain from Russia and China an extension of the applicability of the snapback mechanism (set to expire in October 2025) as an additional guarantee against Iran leaving the table. The EU could follow that up by openly supporting the nuclear deal and pledging to expand economic relations and political dialogue with Iran if Tehran takes into consideration its concerns about the illegal detention of dual nationals and about arms supplies and military know-how to Russia. The Trump Administration can put on the table the re-opening of economic relations with the United States to push Iran to make concessions on the enrichment front.

In short, the technical conditions for a verifiable and sustainable non-proliferation agreement exist, provided that the US Administration reneges on the ambition to dismantle Iran’s enrichment industry.

Solid premises, dim prospects

Should the Trump Administration maintain its zero-enrichment demand, driven by a prevailing perception that Iran is at its weakest and by pressure from Israel and Congressional hardliners, prospects for a deal would all but evaporate.[15]

It would be a great tragedy if the negotiation foundered on US inflexibility. Perceiving, or claiming, that it has exhausted the diplomatic option, the Trump Administration would then have strong political incentives to follow the longstanding advice of Israel’s government and bomb Iran’s nuclear facilities. The risk of sustained regional instability would increase manifold, as Iran would most likely not idly sit by but retaliate, possibly with a missile and drone attack on Israel as well as by directing its allies in Iraq to target US forces there and threatening shipping lines in the Gulf.

The tragedy would be all the greater not just because it is avoidable, given that both sides want to avert a conflict, but also because the foundations for a sustainable agreement are stronger today than they were ten years ago.


Riccardo Alcaro is Research Coordinator and Head of the ‘Global actors’ programme at the Istituto Affari Internazionali (IAI). Ludovica Castelli is a researcher in the IAI’s ‘Multilateralism and global governance’ programme.

[1] Michael Crowley et al., “Israel Appears Ready to Attack Iran, Officials in U.S. and Europe Say”, in The New York Times, 11 June 2025, https://www.nytimes.com/2025/06/11/us/politics/iran-us-iraq-diplomats-mi....

[2] E3/EU+3, Joint Comprehensive Plan of Action, Vienna, 14 July 2014, https://2009-2017.state.gov/e/eb/tfs/spi/iran/jcpoa/index.htm.

[3] Trita Parsi, Losing an Enemy. Obama, Iran, and the Triumph of Diplomacy, New Haven/London, Yale University Press, 2017.

[4] White House, Remarks by President Trump on the Joint Comprehensive Plan of Action, 8 May 2018, https://trumpwhitehouse.archives.gov/briefings-statements/remarks-presid....

[5] See remarks by President Trump as posted on the White House’s @RapidResponse47 X account on 13 May 2025: “@POTUS: I’m here today not merely to condemn the past chaos of Iran’s leaders, but to offer them a new path and a much better path toward a far better and more hopeful future” https://x.com/RapidResponse47/status/1922323321082778024.

[6] White House, Remarks by the President on the Iran Nuclear Deal, 5 August 2015, https://obamawhitehouse.archives.gov/the-press-office/2015/08/05/remarks....

[7] Riccardo Alcaro, Europe and Iran’s Nuclear Crisis. Lead Groups and EU Foreign Policy-Making, Cham, Palgrave Macmillan, 2018.

[8] Faramarz Davar, “How the Snapback Mechanism Brings Back Sanctions on Iran”, in IranWire, 25 November 2024, https://iranwire.com/en/politics/136431.

[9] “Exclusive: Iran ‘Likely’ to Open New Enrichment Site If E3 Pursues Censure at IAEA”, in Amwaj.media, 10 June 2025, https://amwaj.media/en/media-monitor/exclusive-iran-likely-to-open-new-e....

[10] Alexander Langlois, “Saudi Arabia Changes its Tune on Nuclear Negotiations with Iran”, in Gulf International Forum, 13 May 2025, https://gulfif.org/?p=37025; “UAE: MBZ’s Plan to Support U.S.-Iran Nuclear Talks”, in Tactical Notes, 23 April 2025, https://www.tacticalreport.com/daily/63472.

[11] “Trump Says He’s Less Confident about Nuclear Deal with Iran”, in Reuters, 11 June 2025, https://www.reuters.com/world/middle-east/trump-says-he-is-less-confiden....

[12] IAEA, IAEA Director General’s Introductory Statement to the Board of Governors, 9 June 2025, https://www.iaea.org/node/219985.

[13] E3, IAEA Board of Governors on the JCPoA, June 2025: E3 Statement, 11 June 2025, https://www.gov.uk/government/speeches/iaea-board-of-governors-on-the-jc....

[14] Barak Ravid, “Scoop: U.S. Nuclear Deal Offer Allows Iran to Enrich Uranium”, in Axios, 2 June 2025, https://www.axios.com/2025/06/02/iran-nuclear-deal-proposal-enrich-uranium.

[15] Ludovica Castelli, “Language, Memory, and the Fragility of US–Iran Nuclear Diplomacy”, in Stimson Commentaries, 17 April 2025, https://www.stimson.org/?p=107233.