The US and Israel’s war with Iran makes uranium stocks unsafe

The US and Israel’s war with Iran makes uranium stocks unsafe

By Dan Vergano edited by Claire Cameron

This past weekend, the Trump administration and Israel launched a war with Iran over the latter nation posing an imminent threat, largely because of its nuclear ambitions. The US and Israel hit a number of military and leadership targets related to the country’s uranium enrichment program. But the fate of Iran’s partially enriched uranium – the war’s casus belli – is unlikely to be decided by the conflict, non-proliferation experts say.

“Without effective monitoring, the whereabouts and security of Iran’s nuclear material will now become even more uncertain,” said Daryl Kimball, Thomas Countryman and Kelsey Davenport, nuclear nonproliferation experts at the Arms Control Association in Washington, DC, in a statement released Saturday.

The US conflict is “not justified on non-proliferation grounds”, they said, adding that there were reports of progress towards a deal to limit Iran’s nuclear program before the war began.

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Last Friday, hours before US bombs hit Tehran, the International Atomic Energy Agency (IAEA) released a report indicating that Iran has not allowed inspections at any of its four declared uranium enrichment facilities since US and Israeli airstrikes on the three such sites then known to be operational were carried out last June.

Uranium must be concentrated, or enriched, to the isotope uranium 235 in order to serve as either nuclear reactor fuel or material for nuclear weapons. The IAEA estimated that Iran had 441 kilograms of 60 percent enriched uranium – enough for 10 nuclear weapons if the material was further enriched – before the military action in June 2025. It is unclear how much remains after the latest airstrikes, but US and Iranian negotiations ahead of last Saturday’s attack reportedly included the status of the stockpile, says nuclear security expert Edwin Lyman of the Union of Concerned Scientists. That “would assume it was still under Iran’s control,” he says.

Iran’s enrichment program was set back in the June 2025 airstrikes, says Ian Stewart of the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies in Monterey. And the country’s leaders did not seem keen to quickly rebuild it, perhaps for fear of further conflict. “Iran cannot now rapidly acquire nuclear weapons, but the risk is that an extremist could take responsibility and move forward with the program,” he says.

“Now any attempt to recover the material or further process it, without a diplomatic agreement and inspector access, will become an urgent matter requiring an even more extensive intervention,” adds Stewart.

In January, satellite images of the Isfahan nuclear enrichment facility suggested that Iran may be recovering uranium stocks from the bombed site. The US and Israel reportedly struck Isfahan again this past weekend. However, in a statement on Monday, IAEA Director General Rafael Mariano Grossi said that “we have no indication” that any of Iran’s nuclear facilities have been hit. – So far, no increase in radiation levels above the usual background levels has been detected in countries bordering Iran, Grossi said.

While not fully enriched to weapons grade, Iran’s uranium stockpile provides a capacity to build “several” nuclear explosive devices right now that would have “significant” yields, Lyman says. It may also be possible to deliver crude bombs with hidden means, he adds. “However, the potential cost to Iran of taking such a drastic step may well outweigh any benefits, given the unpredictability of how the United States and other nations may respond,” Lyman says.

Editor’s Note (3/2/26): This story is in development and may be updated.

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