A landmark nuclear deal, a dramatic withdrawal, and a second chance blown apart by bombs, this is how US-Iran nuclear diplomacy unravelled once again.
The 2015 Iran Nuclear Agreement
In 2015, under President Barack Obama, the United States and five other world powers (the UK, France, Russia, China, and Germany) signed the Joint Comprehensive Plan of Action (JCPOA) with Iran. The deal was designed to significantly limit Iran's nuclear capabilities in exchange for relief from international sanctions.
Among its key terms: Iran agreed to cap uranium enrichment at 3.67% for 15 years, far below the weapons-grade level of 90%, and cut its enriched uranium stockpile from 10,000 kg to 300 kg. It was restricted to using only 5,060 IR-1 centrifuges and barred from conducting enrichment at the underground Fordow facility. The Arak heavy-water reactor was redesigned to prevent weapons-grade plutonium production.
To ensure compliance, Iran accepted the Additional Protocol of the International Atomic Energy Agency (IAEA), granting inspectors round-the-clock access to nuclear sites. In exchange, the UN, EU, and US lifted nuclear-related sanctions, unfreezing billions in assets and reopening Iran's access to global oil and finance markets. The JCPOA also extended Iran's "breakout time" for producing bomb-grade material from a few months to at least one year.
Why Donald Trump Withdrew The US From The Deal
US President Donald Trump officially exited the JCPOA on May 8, 2018, labelling it a "terrible, one-sided deal" that benefited Iran much more than the US. He argued the agreement was the "worst ever" and "defective at its core" with sunset clauses that would eventually allow Iran to resume enrichment without oversight, and it failed to address ballistic missiles, regional behaviour, or Iran's support for militant proxies.
Trump also cited long-standing Israeli and Saudi criticisms, claiming that Iran had used the relief from sanctions to bankroll terrorism and military operations across the Middle East. He, at the time, vowed to apply "maximum pressure" by reimposing sanctions on Iran's oil, banking, and shipping industries, aiming to force Iran into renegotiating a more comprehensive deal.
A Second Chance, Then Strikes
Fast forward to 2025. Trump, now back in office for a second term, surprised many by wanting to renegotiate a new, tougher version of the nuclear deal. Quiet negotiations were underway. The proposed agreement would reportedly restore caps on enrichment, re-enable full IAEA monitoring, and include additional restrictions on Iran's missile development.
As talks advanced, so did opposition. Israeli Prime Minister Benjamin Netanyahu, who has claimed for over 30 years that Iran is racing toward a nuclear bomb, stepped up pressure on Washington. He dismissed the diplomatic track as naive and warned that Iran was only "weeks away" from weaponising its uranium stockpile.
Days before the expected signing of the new deal, Israel launched a series of preemptive airstrikes on Iranian nuclear facilities, including targets near Tehran. Israeli officials said the strikes were based on "clear and time-sensitive intelligence."
The attacks shattered diplomatic momentum. In the immediate aftermath, the US backed its ally. Trump authorised precision airstrikes of his own, with B-2 stealth bombers and Tomahawk cruise missiles targeting Iran's key nuclear sites: Fordow, Natanz, and Isfahan.
