Iran-US Nuclear Talks: Prospects and Europe’s Role

The renewal of talks between the US and Iran over the Iranian nuclear programme is a decisively positive development. Both the Iranian nuclear programme and US pressure on Iran are approaching inflection points – as Tehran continues to advance its capabilities and Washington threatens to resort to military action if a diplomatic solution cannot be reached. The opening of a diplomatic track between Washington and Tehran offers an alternative to these highly escalatory dynamics.

Nuclear diplomacy with Iran has never been easy, nor will it be this time. Addressing key concerns over Iran’s nuclear programme will require securing concessions from Tehran that it has been unwilling to make in past iterations of nuclear diplomacy. These persistent challenges, combined with a compressed timeline to secure meaningful progress on key issues, will require setting reasonable expectations and bringing to bear both incentives and levers of pressure. The E3 (UK, Germany and France) – which will have to decide later this year whether to ‘snap-back’ UNSC sanctions on Iran or let them lapse – has an important role to play.

Setting Expectations

The US has not been clear on what it expects to secure from Iran in this latest attempt at nuclear diplomacy. Trump has stated in public that he wants to prevent Iran from acquiring a nuclear weapon. That, in itself, is not actually saying much. Everyone that has been involved in nuclear diplomacy with Iran over the last nearly quarter of a century has – presumably – engaged with Tehran with similar motivations: to prevent Iran from acquiring a nuclear weapon. The challenge lies in determining what state the Iranian nuclear programme should be in and how much transparency would be required to abate concerns over potential Iranian weaponisation. Equally important is the question of what controls on its programme Iran would be willing to accept and in exchange for what.

Any suggestion of a full and permanent dismantlement of the programme cannot be taken seriously. Iran has long refused to give up its enrichment capabilities, let alone the whole of its nuclear fuel cycle; it is unlikely to change course now. The fate of Libya’s Muammar Gaddafi after the dismantlement of the country’s WMD programme will be front of mind for Tehran. As a party to the Nuclear Non-Proliferation Treaty, Iran maintains the right to pursue peaceful nuclear technology. Furthermore, latent knowledge acquired as a result of Iranian activities and research over the last six years – including on enrichment with advanced centrifuge models and the production of uranium metal – cannot be fully rolled back – either through diplomacy or military means.

Realm of the Possible

An optimistic reasonable ultimate outcome of nuclear diplomacy with Iran could be an agreement that covers similar ground as the Joint Comprehensive Plan of Action (JCPOA – colloquially known as the Iran nuclear deal), in the kinds of activities and materials it limits and the kinds of monitoring and verification measures it puts in place. As had been the case under the JCPOA, increasing Iran’s breakout time (the amount of time Iran would require to enrich sufficient uranium for a nuclear weapon) and the transparency of the programme will allow concerned parties to identify an Iranian decision to weaponise and take the necessary measures to address the threat.

It is broadly accepted among experts and diplomats that there is no path back to the 2015 JCPOA because of how far the programme has advanced since then. A renewed agreement is unlikely to recreate the exact limits that had been set out in the JCPOA; however, the agreement still provides a useful outline for key issues that will need to be addressed and negotiations could still secure meaningful reductions in concerning aspects of the programme. This could include, among other provisions: decreasing the levels to which Iran is enriching uranium, reducing Iran’s enriched uranium stocks, limiting the number of centrifuges that Iran is using to enrich, and restricting Iran’s use and further R&D of advance centrifuge models.

Familiar Territory

However, ironing out the myriad of highly-technical issues that will need to be addressed to reach an agreement that meaningfully and sustainably addresses key concerns will take months – if not longer. Negotiations for the original JCPOA took years. Efforts to return the US and Iran to compliance under the Biden administration included several rounds of talks that stretched over months; they ultimately failed. Iran is now arguably under greater pressure than it had been during the time of the Biden administration – both as a result of degraded conventional capabilities and regional alliances and increased military threats from the US. However, the fundamental challenges which have repeatedly frustrated negotiations persist.

Iran still relies on its advanced nuclear programme as a key source of deterrence – perhaps more so now that its other deterrent capabilities have been weakened. Providing Iran with the economic benefits that it expects in exchange for any concessions will still rely on private sector willingness to do business in Iran – a hard sell under continued non-nuclear European and US sanctions. Offering Iran guarantees that the next US administration will not withdraw from whatever agreement is concluded will also be difficult and will have to contend with persistent domestic US political opposition to any diplomacy with Iran. In Tehran too, there is no political concensus on whether a deal with Washington should be the preferred course of action. Across the Middle East, concerns persist that a nuclear deal would not address what Iran’s neighbours perceive to be a greater direct threat to their security – Iran’s missile capabilities and support for regional proxies. Israel or others could yet undermine efforts at diplomacy.

Pressed for Time

In the face of all these persistent challenges, the clock is ticking. Trump has apparently given Iran two months to address concerns over its nuclear file – although it is unclear what kind of progress he expects to see in that time and when the countdown actually started. A more clearly defined time marker is the expiry in October 2025 of the ‘snap-back’ provision in UN Security Council Resolution 2231 (UNSCR 2231 – the implementing resolution for the JCPOA). The provision allows the remaining parties to the JCPOA – namely, Russia, China and the E3 – to reimpose on Iran the UNSC sanctions that had been in place prior to the JCPOA. Should the E3 allow the provision to expire, they will lose one of the few remaining levers they have to incentivise Iranian cooperation on the nuclear file. Imposing new UNSC sanctions on Iran after the expiry of the ‘snap-back’ provision would be highly unlikely in the current geopolitical climate, with Russia and China wielding veto rights. However, a decision to ‘snap-back’ could risk retaliation from Iran and could undermine whatever progress is being made in US-Iran talks.

As notice will have to be given before sanctions are ‘snapped back’, an E3 decision on whether to use or lose this leverage will have to come sooner than October – likely before early autumn. Suggestions that an extension of the provision’s expiry could be sought are not practical. Such an extension would likely require negotiating and adopting a new UNSC resolution – a challenging proposition, for the same reason that adopting additional UNSC sanctions after ‘snap-back’ expiry would be difficult. Iran would also have little reason to keep the metaphorical Sword of Damocles hanging over its head longer than it must. Any proposal of extending the ‘snap-back’ provision is unlikely to be accepted by hardliners in Tehran. Instead, Iran will be incentivised to give Trump just enough to keep him at the table, while dragging out talks in the hopes that the E3 will let the provision lapse rather than antagonise the White House.

The E3 cannot allow themselves to be cornered in this way and need to make clear that they will not be afraid to trigger ‘snap-back’ if satisfactory progress is not made in US-Iran talks. Iran has more to lose in walking away from the negotiating table after ‘snap-back’ than does the US. Should US-Iran negotiations still be progressing, Iran will not be incentives to retaliate, but rather to see what concessions it may be able to secure by staying at the table. As such, the prospect of potentially reaching an agreement – which could, among its other provisions, include a re-suspension of UNSC sanctions – may temper whatever retaliatory action to ‘snap-back’ Tehran may have pursued otherwise. Lifting sanctions after they have been reimposed will be much easier than imposing new ones after the ‘snap-back’ provision expires without sanctions having been reimposed.

A credible prospect of ‘snap-back’ will also serve to give the US additional leverage in negotiations – short of issuing further military threats. Close co-ordination with Washington on any decision to reimpose UNSC sanctions – as is, doubtless, already going on – will help to coordinate approaches and narratives around any such decision and avoid the perception of a break between the US and Europe on this file.

Credible Off-Ramp

However, for the threat of ‘snap-back’ to be credible, avoiding it must remain a realistic prospect for Iran. To that end, the E3 will have to set reasonable expectations for what can be achieved before the ‘snap-back’ provision expires this autumn. Communicating them clearly, while setting the bar (not unreasonably) high, can be helpful to setting the parameters for an interim agreement.

One key priority should be increasing transparency of the nuclear programme. The IAEA has said that it has lost continuity of knowledge over the Iranian programme; re-establishing the baseline of Iran’s nuclear activities and equipment will be necessary for any serious negotiations. Any interim agreement should – at a minimum – involve an Iranian return to the verification and monitoring provisions included in the original JCPOA. This should include renewed Iranian application of the Additional Protocol (AP) and of the modified Code 3.1 of the Subsidiary Arrangements to its Comprehensive Safeguards Agreement (CSA). The AP would grant the IAEA greater access to more Iranian facilities (including centrifuge production sites); while modified Code 3.1 will require Tehran to provide earlier notification of any decision to construct new nuclear facilities.

Further expectations may include a reapplication of other monitoring and verification provisions that had been included in the JCPOA and which go beyond the provisions of Iran’s CSA and AP. An interim agreement could also include a range of other provisions, which would – to varying degrees – help to address concerns over Iran’s breakout time : for instance, not using 20% feed for enrichment, halting production of 60% enriched uranium, downblending stocks of 60% enriched uranium (to 20% or even lower levels), and/or stopping enrichment with advanced centrifuges (IR-6, IR-4 and IR-2m models). These steps should be technically achievable in the next six months.

While the E3 may not be directly involved in the US-Iran negotiations as they move into their second round this coming Saturday, Europe still has a role to play. European negotiators have built up extensive expertise on the nuances of the Iranian nuclear programme and on negotiating with Tehran. The US administration would greatly benefit from tapping into this knowledge. Furthermore, Europe still has leverage it can bring to bear to help move talks along productively. Iran cannot be allowed to drag its feet in the negotiations and must demonstrate quickly that it is engaging in good faith and willing to make meaningful progress in addressing concerns. Making clear that ‘snap-back’ remains on the table – while offering a clear path to avoiding it – may help put the necessary fire under Tehran’s feet.

© RUSI, 2025.

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