As Iran resumes long-awaited nuclear talks with major European powers in Istanbul, hopes rise over the possibility of finding a negotiated settlement to the contentious issue that has vexed negotiators for decades.
The Istanbul talks with the UK, France, and Germany come days after the Trump administration formally presented Iran with a written draft of the deal —the first since negotiations began in early April—marking a key moment in the ongoing diplomatic process, according to news reports.
US President Donald Trump, speaking in Saudi Arabia during his ongoing Middle East tour, described the proposal as “an olive branch” but warned it “will not last forever”. The offer outlines limits on Iran’s nuclear programme for civilian purposes and includes strict monitoring measures.
Earlier, Iran shared its own written ideas, which led to back-and-forth talks between expert teams.
Now, Iranian officials say they may accept a deal that allows civilian nuclear use, bans weapons-grade uranium, and includes full inspections in return for lifting sanctions.
Meanwhile, European diplomats have warned that failure to reach an agreement by August may trigger “snapback” sanctions under the 2015 nuclear deal.
Here is a timeline of key events in Iran’s nuclear negotiations.
Early developments
1967: Under the US-led “Atoms for Peace” programme, Iran receives its first nuclear reactor during the reign of Shah Mohammad Reza Pahlavi.
1984: Iran revives its nuclear programme with assistance from Pakistan, China, and Russia.
2002: Secret nuclear sites at Natanz and Arak are revealed by Western intelligence and an Iranian opposition group, prompting international concern.
E3 diplomacy begins
2003: The UK, France, and Germany (E3) begin talks with Iran following an IAEA resolution. Iran temporarily suspends uranium enrichment.
2006: Iran announces it will restart enrichment under President Mahmoud Ahmadinejad. The UN imposes sanctions, and the E3 walk out of stalled talks.
2009: Under President Obama, the US and Iran establish a secret backchannel via Oman.
2012: US and Iranian officials hold face-to-face secret talks in Oman.
2013: Reformist President Hassan Rouhani pursues diplomacy; an interim deal (Joint Plan of Action) is signed in Geneva.
2015: Iran and the P5+1 (US, UK, France, Russia, China, Germany) sign the Joint Comprehensive Plan of Action (JCPOA) in Vienna, limiting Iran’s nuclear programme in exchange for sanctions relief.
2016: The IAEA verifies Iran’s compliance; sanctions are lifted on Implementation Day, and monitoring begins.
Collapse of the deal
2018: President Trump withdraws from the deal, calls it “the worst deal ever,” and reimposes sanctions. He promises better terms to curb Iran’s missile programme and regional influence, but no new talks follow during his term.
2019–2020: Iran begins rolling back its commitments, increasing uranium enrichment and reducing IAEA access.
2021: Indirect talks under the Biden administration aim to revive the deal, but no agreement is reached. Iran enriches uranium up to 60 percent, nearing weapons-grade levels.
2022: Russia invades Ukraine and increasingly relies on Iranian drones and missiles, deepening military ties.
2022: Iranian officials publicly state the country has the technical ability to build a nuclear bomb if it chooses.
2023: Iran increases enrichment levels close to weapons-grade. No formal agreement was reached despite continued backchannel efforts.
Renewed efforts in 2025
2025: The US under Trump reopens talks. Envoy Steve Witkoff delivers a formal written proposal to Iran during negotiations in Oman—the first such offer in years.
15 May 2025: Iran reviews the US proposal with top leadership. The UK, France, and Germany prepare for talks in Istanbul and warn that failure to reach a deal by August may lead to the reimposition of sanctions under the JCPOA’s “snapback” mechanism.
The resumed nuclear negotiations between Iran and the United States stand out as one of the most significant diplomatic developments following Donald Trump’s unilateral withdrawal of the Unit…
