Explained | How Trump blindsided Netanyahu with his Iran nuclear gamble

Washington: US President Donald Trump blindsided Israeli Prime Minister Benjamin Netanyahu last month with a gamble on immediately opening negotiations with Iran. Now, the success of those talks hinges on winning a handful of key concessions to stop the Islamic Republic from developing a nuclear bomb, eight sources said.

The pivot to negotiations with Iran in April was a shock for Netanyahu, who had flown to Washington seeking Trump's backing for military strikes on Iran’s nuclear facilities and learned less than 24 hours before a joint White House press event that US talks with Iran were starting within days, four sources familiar with the matter told Reuters.

Tehran's leadership remains deeply concerned that Netanyahu may launch a strike - deal or no deal, a senior Iranian security official said. However, in just three weeks, the US and Iran have held three rounds of talks aimed at preventing Tehran from building a nuclear weapon in return for sanctions relief. A fourth round is expected to take place in Rome soon.

For this story, Reuters spoke to officials and diplomats from all sides of the negotiations who disclosed previously unreported details under discussion. All requested anonymity to speak about delicate ongoing conversations.

An initial framework under discussion preserves the core of the 2015 Joint Comprehensive Plan of Action (JCPOA) - scrapped by Trump in 2018 during his first term, eight sources said.

A deal may not look radically different to the former pact, which he called the worst in history, but would extend duration to 25 years, tighten verification, and expand so-called sunset clauses that pause but don't completely dismantle aspects of Iran's nuclear program, all the sources said.

Under the terms being discussed, Iran would limit stockpile size and centrifuge types, and dilute, export or seal its 60 per cent uranium stock under unprecedented International Atomic Energy Agency (IAEA) scrutiny - all in exchange for substantial sanctions relief, all the sources said.

The US State Department, Iran's foreign ministry, and Netanyahu's office did not respond to requests for comment.

Dennis Ross, a former negotiator under both Republicans and Democrats, said that any new agreement must go further than the JCPOA by imposing a permanent, structural change in Tehran’s nuclear capabilities - shrinking its infrastructure to the point where developing a bomb is no longer a practical option.

"Anything less would leave the threshold threat intact," he told Reuters.

But several red lines are emerging that negotiators will have to circumvent to reach a deal and avert future military action.

Foremost is the question of Iran's capacity to enrich uranium, something Washington and Israel say must stop entirely, leaving Iran reliant on imported uranium for Bushehr, its only existing nuclear power plant, located on the Gulf coast.

Netanyahu is demanding “zero enrichment” and a Libya-style deal that dismantles Iran's nuclear infrastructure. Iran says its right to enrich is not negotiable. However, the size of the uranium stockpile, shipping stocks out of the country and the number of centrifuges are under discussion, three Iranian officials said.

Under proposals discussed in rounds of talks in April, Iran would cap enrichment at 3.67 per cent, in line with the JCPOA, all the sources said, including three Iranian officials. Tehran is also open to granting the IAEA expanded access to its nuclear sites, the Iranian sources said.

The proposals do not seek to dismantle Tehran’s nuclear infrastructure entirely as Israel and some US officials want, but aim to lock in permanent constraints on uranium enrichment that deter any breakout, the sources said. US Middle East envoy Steve Witkoff appeared to acknowledge that position in comments last week, but later said Iran must "stop and eliminate" enrichment.

One way out could be for Iran to accept long breaks to the enrichment program, through an extension of sunset clauses, said Alex Vatanka, a senior fellow and the founding director of the Iran program at the Middle East Institute in Washington.

"The Iranians, if they were smart, would settle for much longer sunset clauses going into the future," Vatanka said, emphasising the importance of each side being able to claim victory in the talks.

Another possible compromise could involve Iran retaining minimal enrichment, with 5,000 centrifuges, while importing the rest of the enriched uranium, possibly from Russia, one of the three Iranian sources, a senior security official, told Reuters.

In return for limits on enrichment, Tehran has demanded watertight guarantees that Trump would not again ditch a nuclear pact, the three Iranian officials said. Among the red lines mandated by Supreme Leader Ayatollah Ali Khamenei is reducing the amount of enriched uranium it stores to below the level agreed in the 2015 deal, the three sources said. Iran has been able to "significantly" increase the amount of uranium it can enrich to 60 per cent purity, the IAEA said in December.

The JCPOA only permitted Iran to accumulate enriched uranium produced by its first-generation IR-1 centrifuges, but now Iran is using far more advanced models banned under the 2015 deal.

A senior regional source close to Tehran said the current debate over Iran's uranium stockpiles centres on whether Iran "will keep a portion of it - diluted - inside the country while sending another portion abroad, possibly to Russia."

According to the source, Iran has even floated the idea of selling enriched uranium to the United States. Iran currently operates around 15,000 centrifuges. Under the JCPOA, Iran was allowed to operate around 6,000.

"Essentially, the negotiations are shaping into a “JCPOA 2” with some additions that would allow Trump to present it as a victory, while Iran could still keep its right to enrichment," the senior Iranian official said. Another sticking point relates to Iran's ballistic missile manufacturing capacity. Washington and Israel say Iran should stop making missiles. Iran counters that it has a right to self-defence. One Iranian official previously told Reuters it would not go beyond the requirements of the 2015 deal, offering only to avoid building missiles capable of carrying nuclear warheads as a "gesture of goodwill."

Washington is pressing to include the ballistic missile program in the talks, but Tehran "continues to reject any discussion," said one regional security official. "The problem", he added, "is that without addressing the missile issue, Trump cannot claim that the new deal goes beyond the JCPOA."

Former negotiator Ross points out the contradiction: Trump abandoned the JCPOA for being too weak, and as a result, now faces a reality where Tehran stands at the threshold of nuclear weapons capability.

"Accepting a deal that mirrors or softens the original would be politically indefensible," he said, suggesting a deal must slash centrifuges from 20,000 to 1,000, ship out all enriched stockpiles, and impose intrusive, penalty-backed inspections.

Strike Risk

Vatanka, the analyst, likened Iran's current predicament to the 1988 decision by the regime's founder, Ruhollah Khomeini, to accept a ceasefire with Iraq - a moment he famously likened to drinking "the bitter chalice of poison"

"It's about survival," Vatanka said. "It's not capitulation."

Diplomats say Netanyahu sees a rare opening: last year’s military campaigns crippled Iran’s air defenses, and decimated Hezbollah’s missile arsenal - Tehran’s primary deterrent.

"This is a historic window for Israel to strike Iran's nuclear sites," said an official in the Middle East. The United States, he said, opposes such a move for several reasons - chief among them the concerns of Gulf Arab states, which Washington cannot ignore given its deep strategic and economic ties in the region.

"Still, it must weigh Israel's security calculations," he said. "So while the US may not take part directly, it could offer indirect support. It would be a difficult operation for Israel, but not an impossible one." The US military has surged assets in recent weeks to reinforce the Middle East. The Pentagon has deployed six B-2 bombers to the Indian Ocean island of Diego Garcia - a location used in the past to support its military operations in the Middle East.

Additionally, the US currently has two aircraft carriers in the region and has moved in air defence systems from Asia.

Alan Eyre, a former US diplomat and Farsi-speaking Middle East expert, warned that a strike may slow Iran's program, but won't eliminate it. "You cannot bomb know-how," he said. "The knowledge is there. Iran has mastered uranium enrichment.