The US-Israel attack on Tehran on February 28 comes as a negotiating team led by Oman’s foreign minister made a last ditch attempt at an agreement between the US and the Ayatollahs to prevent war.

Iran agreed to a “zero bomb-grade” uranium stockpile and zero enrichment the evening before on February 27, according to reports. Mediators said Washington and Tehran were edging towards a breakthrough agreement the day before designed to prevent precisely such a confrontation.

A negotiating effort led by Oman’s Foreign Minister Badr Albusaidi had been attempting a final compromise between the two sides just before the strikes were launched.

According to diplomatic reports circulating on February 27, Iran had agreed the evening before to unprecedented nuclear concessions, including a commitment to maintain a “zero bomb-grade” uranium stockpile and effectively accept zero accumulation of highly enriched material.

However, it appears that the Trump administration was not satisfied with the progress made and has instead given the go ahead for a full-scale attack on Iran in cooperation with Israel. In a video posted on social media US President Donald Trump called on the people to seize a “once in a generation opportunity,” and overthrow the government.

The enrichment limits proposal represented a significant shift in Tehran’s position. Oman’s Albusaidi said Iran had reportedly made a commitment it had never previously accepted: no remaining highly enriched uranium capable of rapid weaponisation.

Iran has some 440kg of uranium enriched to 60% that was the target of last year’s US bombing attack on mountain nuclear research labs. Although Trump claimed that Iran’s stockpile was “obliterated” it has since transpired the stockpile survived the bunker-busting bombs and has been recovered by the Iranian authorities.

Now it appears the authorities were prepared to give up their stockpile as part of the new deal and the surviving highly enriched material would be diluted down to power-reactor levels. Uranium only has to be enriched to 3-5% for use in nuclear power plants (NPPs) but to 90% before it becomes weapons grade. As part of the agreement, the International Atomic Energy Agency would also be given unfettered access to the facilities — a provision diplomats describe as the essential enforcement mechanism behind any deal.

Albusaidi characterised the arrangement as a “structural reset” of Iran’s nuclear programme. If Iran later chose to break the deal, it would have given up its reserve of enriched uranium making it significantly harder to restart Iran’s nuclear programme. Diplomats involved in the talks hailed the proposal as eliminating the “stockpile risk” that has haunted negotiations since the collapse of the 2015 Joint Comprehensive Plan of Action (JCPOA) nuclear accord.

“The most important achievement is the agreement that Iran will never possess nuclear material capable of producing a bomb,” Albusaidi said, adding that zero stockpiling was “something completely new” compared with earlier agreements.

He argued that eliminating stockpiles fundamentally altered the proliferation equation. Yet even as negotiators spoke of progress, military preparations accelerated.

Decapitation strategy

“I’ve been messaging my sources who suggest that the US involvement in this attack is aimed at ‘decapitating the Iranian regime’,” Alan Fisher, reporting for Al Jazeera from Washington, said in a social media post.

“They say that from what they can understand, the attacks were concentrated on areas where Supreme Leader Ayatollah Ali Khamenei may be sheltering, so the intention was to try and take out the head of the regime and then see what would happen afterwards.”

Separately, there have been unconfirmed reports that dovish Iranian President Masoud Pezeshkian was targeted by the missile strikes, and that other senior figures in the regime were targeted and killed.

A decapitation strategy mirrors Operation Absolute Resolve on January 3 where the US government removed the sitting president of Venezuela Nicolas Maduro, who is now awaiting trial in New York on “narco-terrorism” charges. If the Trump administration is attempting a similar decapitation strategy in Iran, it would mark a dramatic escalation from coercive diplomacy towards regime-change logic — a move that US allies in the Gulf had reportedly urged Washington to avoid.

“There are countries that have been cautioning the US against this attack and wanted to know what the plan for the day after would be, simply because you can’t guarantee that by removing the Supreme Leader you would necessarily form a pro-US government,” Fisher added.

The apparent contradiction between diplomatic progress and military action highlights the deep mistrust shaping the negotiations. Western officials have long argued that Iran’s accumulation of enriched uranium dramatically shortened the timeline for producing a nuclear weapon. International inspectors have repeatedly warned that limited access to key sites has complicated verification efforts.

For Washington and Israel, the fear has been that talks could buy Tehran time. For Tehran, the growing military pressure, as Trump’s “armada” arrives in the Gulf, reinforces the Ayatollah’s belief that the US is not pursuing a non-proliferation strategy but simply after regime-change.

As a moderate actor in the Middle East, Oman’s mediation had aimed to bridge that gap and prevent a region-wide war by reframing the debate away from enrichment levels towards stockpile elimination — effectively trading technical limits for structural safeguards. The foreign minister argued recently that a peace deal was “within our reach” if diplomacy were allowed to continue.

The US-Israeli missile strikes have slammed that window closed. Analysts note that military strikes launched just as concessions emerged will strengthen hardliners inside Iran who have threatened to rain down missiles on Israel and strike US bases across the region.