Why Trump withdrew from the Iran nuclear deal in 2018, and why he wants to renegotiate now

Trump unilaterally withdrew the US from the deal in 2018, during his first term as president.

Why did Trump withdraw from the deal in 2018?

Having deemed the JCPOA one of “the worst and most one-sided transactions” for the US, Trump’s withdrawal was part of his broader undoing of his predecessor’s signature policy achievements. This was especially evident in Trump’s targeting of the terms of the deal — not the idea itself — and his assertions of being a better deal-maker than Obama.

Trump had further rationalised his withdrawal on the deal’s alleged failure to curtail Iran’s ballistic missile programme, and the lack of checks on Iran’s regional proxies — two aspects that were central to Saudi and Israeli opposition to the JCPOA.

But the withdrawal was met with strong international backlash. The IAEA said that Iran was complying with JCPOA-linked restrictions and UNSC Resolution 2231. More importantly, European states continued their commitment to the deal. In 2018 itself, as new American sanctions hit Iran’s energy, petrochemical, and financial sectors, the EU enforced a Blocking Statute to protect European companies doing “legitimate business” in Iran.

But with Trump’s “maximum pressure” leading to at least 1,500 different sanctions on crucial Iranian entities between 2018 and 2021, European efforts failed to prevent companies from abandoning trade and investment in Iran across sectors. This led to Iran, by 2019, beginning a significant roll-back of its commitments, even though it formally remained in the deal.

How has the deal fared since then?

The technical expiry of the JCPOA is in October 2025. But the European failure to lobby a US re-entry, new American sanctions, and Iran’s incremental rollback of its commitments in response has ensured the deal’s progressive weakening.

The Joe Biden administration began to engage in indirect negotiations with Iran in Vienna in 2021. But these failed to reach a decisive outcome despite reportedly coming “closer than ever” in 2022, according to Tehran’s then top nuclear negotiator, Ali Bagheri.

Meanwhile, Iran’s “resistance economy” crumbled with the riyal in free-fall against the US dollar, leading to popular disaffection in the street further flamed by other triggers — such as the death of Mahsa Amini in September 2022 after she was taken into custody by Iran’s morality police.

Parallely, Tehran ramped up its nuclear activity. The suspected Israeli threat furthered this push towards nuclearisation — Iran’s top nuclear scientist and reported weapons program chief Mohsen Fakhrizadeh was assassinated near Tehran in 2020. By 2021, Iran was announcing 61% enrichment, characterising it as a response to alleged Israeli sabotage of its Natanz nuclear facility.

This, along with Iranian support for Russia in its war in Ukraine, meant that by 2023, negotiations were all but stalled. Since the conflict in Palestine began in late 2023, the IAEA has repeatedly warned of a severe lack of transparency, and Iran’s continued production of near-weapons-grade uranium.

Indeed, the suspicion over Iran’s possible closeness to nuclear weaponisation both necessitated regional lobbying for de-escalation during the two rounds of Israel-Iran rocket-airstrike exchanges in 2024 as much as it increased Israeli lobbying for a larger war against Iran.

What has triggered Trump’s turnaround?

By late 2024, the Iranian economy was in dire straits. Newly-elected President Masoud Pezeshkian said that the country faced “very dire imbalances in gas, electricity, energy, water, money and environment.”

This is likely the principal trigger for Iran’s openness to engage with the US. Seemingly siloed from the entrenched and expanding conflict with Israel, the new Iranian government’s outreach to Washington has continued both through third-party-facilitated back-channels and overt publications, policy statements, and declarations by Iranian officials calling for engagement and sanctions relief.

But despite economic stresses and Israeli attacks, Iran’s ability to wield influence through its proxies has remained significant — especially with the Houthis’ continued ability to choke global trade and attack Arab energy infrastructure — bringing new diplomatic arrangements across the Gulf, and supplementing Iran’s nuclear card. The new and deepening rapprochement between Iran and its Gulf partners, in no small part propelled by Israel’s increasing unpopularity in the Arab world, has meant that Trump now faces a dramatically different Middle East than he had done in his first term, when tensions between Saudi Arabia and Iran were soaring.

It is in this context that Trump’s latest comments must be seen. If Tehran reciprocates, it would also cushion any new American concessions to Israel on the Palestine question. As Trump seemingly bypasses Israel to now negotiate with Hamas directly for the release of hostages, mitigating the Iranian nuclear risk would be a significant policy achievement. In any case, the longer the conflict in the Middle East continues, the more the Arab-Israel rapprochement — in Trump’s view, one of his finest diplomatic feats — unravels.

All this said, there remains a strong trust deficit between Washington and Tehran, where both conservatives and reformists specifically blame Trump for upending the JCPOA.

The 2015 deal was not meant to prevent Iran from acquiring nuclear weapons indefinitely. Its “sunset clauses” — which would remove centrifuge restrictions after 10 years and limits on low-enriched uranium after 15 — were central to Trump’s opposition to the deal.

Any American offer that removes these provisions, or imposes even harsher terms, significantly reduces the possibility of an agreement being signed.

Bashir Ali Abbas is a Senior Research Associate at the Council for Strategic and Defense Research, New Delhi