Iran’s Nuclear Programme in the Post-JCPOA Diplomatic Impasse

A decade after the JCPOA, Western nuclear diplomacy with Iran has reached an impasse amidst US–EU divisions, sustained sanctions, and Iran’s eastward pivot

The Joint Comprehensive Plan of Action (JCPOA) expired on 18 October  2025, 10 years after its signing. The deal’s collapse—triggered by the United States (US) withdrawal in 2018 and Iran’s subsequent breach of uranium enrichment limits—underscored the fragility of negotiated constraints on Tehran’s nuclear programme. What remains is a binary choice: negotiate a credible successor framework or accept that Western-led diplomatic engagement with Iran has reached its limits.

Origins of the Post-JCPOA Stalemate

Five rounds of US-Iran talks in early 2025 suggested that diplomacy might gain traction. That prospect collapsed in June when Israeli strikes on Iranian nuclear facilities—conducted with US military participation—forced the cancellation of a planned sixth round. Washington’s role in the subsequent 12-day conflict shattered Iranian confidence in American credibility and, by extension, European reliability, as the European Union (EU) declined to condemn US actions publicly.

Tehran’s narrative hardened accordingly. Iranian officials cast Washington as negotiating in bad faith, using talks to extract concessions rather than seek compromise. US insistence on expanding negotiations beyond the nuclear file to encompass missile programs and regional activities reinforced this view, as did perceptions of Israeli influence over American policy. Supreme Leader Ayatollah Ali Khamenei dismissed US demands as “excessive and outrageous,” framing diplomacy itself as a tool of pressure rather than a mechanism for trust-building through phased sanctions relief.

US insistence on expanding negotiations beyond the nuclear file to encompass missile programs and regional activities reinforced this view, as did perceptions of Israeli influence over American policy.

Diplomatic channels have remained frozen ever since, with sanctions re-emerging as the primary policy instrument. In September 2025, one month before the JCPOA’s expiration, France, Germany, and the United Kingdom (the E3) triggered the snapback mechanism, reinstating United Nations Security Council (UNSC) sanctions lifted in 2015. The measures include arms embargoes, dual-use trade restrictions, and financial and transport controls. The EU layered on asset freezes, travel bans, and sweeping trade and energy sanctions. Washington praised the European initiative as “an act of decisive global leadership”.

To preserve leverage beyond the JCPOA’s termination, the EU and UK opted to keep these restrictions in place. The decision cemented the breakdown in EU-Iranian relations, mirroring the deterioration of US-Iranian relations. It also contradicted repeated overtures by EU High Representative Kaja Kallas, affirming Europe’s openness to renewed diplomacy—gesturesunaccompanied by tangible incentives that might bring Iran back to the negotiations.

The Constraints on Western-Led Nuclear Diplomacy

For Europe, the JCPOA represented more than a non-proliferation agreement. It embodied multilateral crisis management and a commitment to a rules-based international order. Yet compared to 2015, Europe now operates from the margins rather than driving diplomatic strategy. The war in Ukraine and the imperative to end dependence on Russian energy have consumed the EU’s diplomatic capacity, pushing Iran’s nuclear file down the external security agenda. Europe’s continued reliance on NATO’s security architecture has further narrowed its room for an independent Iran policy.

This retreat was evident during Iranian Foreign Minister Seyed Abbas Araghchi’s visit to France, where the nuclear dossier received marginal attention. The encounter reinforced Tehran’s perception that European actions reflect US-Israeli strategic priorities rather than the autonomous diplomacy that produced the original JCPOA. Europe’s influence as a Middle East diplomatic actor has atrophied.

Europe’s continued reliance on NATO’s security architecture has further narrowed its room for an independent Iran policy.

Washington, meanwhile, shows little interest in stabilising the region through nuclear engagement. The November 2025 US National Security Strategy (NSS) relegates Iran to the periphery, emphasising partnerships for trade, energy, and technology—particularly with the Gulf Arab states. Yet even as economic protests erupted across Iran over sanctions-driven hardship, US President Donald Trump threatened military intervention should Tehran target demonstrators. These warnings echo previous ones tied to nuclear advances or missile expansion. Such a priorities-driven approach forecloses rapprochement and amplifies the risk of confrontation.

Trump continues to view Iran as fundamentally weakened by the twelve-day war and sanctions regime, a condition he intends to deepen through additional restrictions on Iranian oil exports to Asia. Any future nuclear agreement would likely come on terms favourable to the United States: suspension of enrichment activities and dismantlement of Iran’s regional proxy networks.

The bottom line is that Brussels and Washington diverge on a strategic approach. The former nominally favours diplomacy, while the latter embraces containment through military threats. On points ofconvergence, both agree on economic coercion. This gap widened during the December 2025 Trump-Netanyahu meeting, where both leaders pledged to prevent Iran from advancing its nuclear and ballistic capabilities. The joint commitment underscored Washington’s detachment from European preferences and reinforced a hardline axis that leaves little space for negotiated solutions.

Any future nuclear agreement would likely come on terms favourable to the United States: suspension of enrichment activities and dismantlement of Iran’s regional proxy networks.

Iran’s View of Western Nuclear Strategy

This perception aligns with Iranian Foreign Minister Araghchi’s guiding principle: “Neither East nor West,” reflecting a rejection of dependence on any external power, particularly Western states. Deputy Foreign Minister for Economic Affairs Hamid Ghanbari dismissed the snapback mechanism as illegitimate, arguing that the EU has squandered its international credibility and now applies double standards. Tehran extends this critique to the United Nations (UN) and its agencies, which it portrays as equally compromised by Western bias.

Following the twelve-day war, Iran curtailed cooperation with the International Atomic Energy Agency (IAEA), blocking monitoring and security assessments at the Fordow and Natanz facilities targeted in the June 2025 strikes. Its commitment to the Non-Proliferation Treaty (NPT) remains ambiguous. While some parliamentarians pushed for withdrawal, Iran remains a signatory, and Araghchi agreed in Cairo in November 2025 to renew cooperation with the UN watchdog under the NPT framework. Yet inspectors have been barred from the damaged enrichment sites, rendering the commitment hollow.

The nuclear threshold thus serves dual purposes: a security buffer and a symbol of strategic autonomy and technological prestige.

Despite losses to its scientific personnel and infrastructure, Iran shows no intention of abandoning its nuclear programme. Though weaponisation remains officially disclaimed, the programme increasingly functions as a deterrent of last resort in a region dominated by US-allied Gulf Arab states and Israeli military power, while also reconstituting strength to proxy networks including Hezbollah and the Houthis. The nuclear threshold thus serves dual purposes: a security buffer and a symbol of strategic autonomy and technological prestige.

More broadly, sanctions have accelerated Iran’s pivot away from Western economic and diplomatic channels. Tehran has deepened engagement through alternative frameworks like the Shanghai Cooperation Organisation (SCO), expanding trade and military agreements with China and Russia. A limited bilateral US-Iran arrangement remains theoretically possible, though Trump’s recent escalation has injected fresh volatility. The latest announcement by the US president that a “massive armada” is headed toward Iran, warning Tehran to “make a deal” or face military strikes, could serve as the impetus for nuclear negotiations. Despite this renewed pressure, the underlying reality persists: neither side perceives a compelling reason to negotiate on terms acceptable to the other, and Trump’s coercive approach risks narrowing rather than widening the diplomatic space.

Conclusion

Apart from ongoing tensions, deeper structural obstacles hamper diplomatic breakthroughs. President Trump’s calls for greater European strategic autonomy cast further doubt on the feasibility of any revived multilateral nuclear framework. Meanwhile, Russia and China have openly opposed the reimposition of UN sanctions, shielding Tehran at the Security Council and sustaining economic ties despite Western pressure. This support insulates Iran from coercion and reinforces its eastward pivot beyond the Western orbit.

Absent a fundamental strategic realignment, Western-led nuclear diplomacy towards Iran has reached an impasse.

Absent a fundamental strategic realignment, Western-led nuclear diplomacy towards Iran has reached an impasse. The absence of coordination between Washington and Brussels, the lack of credible incentives for Tehran, and the erosion of meaningful leverage have left US and European actors with diminishing influence over Iran’s nuclear trajectory and the wider regional proliferation landscape. From Tehran’s vantage point, abandoning its nuclear programme would mean surrendering its final credible deterrent against American and Israeli pressure—a concession the regime shows no willingness to make. Barring unilateral US military action or a broader regional conflagration, Iran’s nuclear file will remain a managed stalemate rather than a resolved crisis, ensuring prolonged instability across the Middle East.

Giada Kabrit is Program Assistant and Intern Coordinator at the Observer Research Foundation, Middle East.