What we know about the damage done to Iran's nuclear program

VIENNA — The big question following U.S. and Israeli attacks on Iran's nuclear program is: What remains of it?

U.S. President Donald Trump has said three targets hit by American strikes were "obliterated." His defense secretary said they were ''destroyed.''

A preliminary report issued by the U.S. Defense Intelligence Agency, meanwhile, said the strikes did significant damage to the Fordo, Natanz and Isfahan sites, but did not totally destroy the facilities.

The head of the International Atomic Energy Agency said that as a result of Israeli and U.S. strikes, the agency has ''seen extensive damage at several nuclear sites in Iran,'' including those three. Israel claims it has set back Iran's nuclear program by ''many years.''

Officials and experts are still assessing the damage, and their evaluation could change.

Two of the major questions they are trying to address are where Iran's stockpile of enriched uranium is and what is the state of the centrifuges that enrich the fuel.

The answer to the first is not clear, but the IAEA believes significant damage was done to centrifuges at the two enrichment facilities in Natanz and Fordo.

The IAEA — and the world — want to know the state of both the uranium and centrifuges because if Iran chooses to make a nuclear weapon, then making the fuel required would be just a short, technical step away.

Iran has always maintained that its nuclear program is peaceful.

But it has enriched significant quantities of uranium beyond the levels required for any civilian use, and Israel launched strikes on nuclear and military targets on June 13, accusing Iran of trying to develop atomic weapons.

The U.S. joined that attack on Sunday, dropping 14 bunker-buster bombs on two sites. Iran retaliated with strikes on Israeli and American targets. Israel and Iran have since agreed to a ceasefire.

Here's what we know — and don't know — about the state of Iran's nuclear program.

It's possible the nuclear fuel was moved

At least some of Iran's highly enriched uranium may have been moved before the U.S. strikes, the assessment from the DIA suggests, according to two people familiar with the evaluation. The people were not authorized to address the matter publicly and spoke on condition of anonymity.

That would mean that some of the stockpile may have survived.

The assessment was preliminary and will be refined as new information becomes available, the agency has said. Its authors also characterized it as ''low confidence,'' an acknowledgement that the conclusions could be mistaken.

The White House has called the assessment ''flat-out wrong,'' pointing to the power of the bombs to back up the president's characterization that the sites hit had been destroyed.

Iran has previously threatened to hide its enriched uranium if attacked, and reiterated its pledge the day Israel launched its military campaign. Enriched uranium is stored in canisters that can be moved around fairly easy.

In May, the IAEA, which is the U.N. nuclear watchdog, said Iran had amassed 408.6 kilograms (900.8 pounds) of uranium enriched up to 60%. If it is further enriched to 90%, it would be enough to make nine nuclear weapons, according to the U.N.'s yardstick, though a weapon would require other expertise, such as a detonation device.

Before the war, experts believe the stockpile was mainly stored in two places: underground tunnels at a facility in Isfahan, and in a heavily fortified underground enrichment site in Fordo.

U.S. Defense Secretary Pete Hegseth told reporters Thursday that he was "not aware of any intelligence that I've reviewed that says things were not where they were supposed to be — moved or otherwise.''

Trucks seen at nuclear facility prompt speculation

Satellite imagery showed trucks and bulldozers at the Fordo site beginning June 19, three days before the U.S. struck.

Eric Brewer, a former U.S. intelligence analyst and now deputy vice president at the Nuclear Threat Initiative, said it's ''plausible'' that Iran used the trucks to take nuclear fuel away.

But Jacob Kirkegaard, senior fellow at the Breugel think tank in Brussels, disagreed: ''I think that that was a decoy more than anything else.''

Subsequent satellite imagery ''revealed that the tunnel entrances into the underground complex had been sealed off with dirt prior to the U.S. airstrikes,'' said Stephen Wood, senior director at American satellite imagery and analysis firm Maxar Technologies. ''We believe that some of the trucks seen on 19 June were carrying dirt to be used as part of that operation.''

Trump offered a similar explanation.

In a post on his Truth Social network on Thursday, he wrote: ''The cars and small trucks at the site were those of concrete workers trying to cover up the top of the shafts. Nothing was taken out of facility. Would take too long, too dangerous, and very heavy and hard to move!''

Gen. Dan Caine, chairman of the Joint Chiefs of Staff, told reporters that the bombs were dropped onto the two main ventilation shafts of Fordo.

He said Iran attempted to cover the shafts with concrete before the U.S. attack, but the cap was ''forcibly removed by the main weapon.''

Centrifuges are highly sensitive and vulnerable to damage

Inspectors from the IAEA have remained in Iran throughout the war, but they are currently unable to inspect any nuclear sites due to safety concerns.

But with the ''explosive payload utilized, and the extreme vibration-sensitive nature of centrifuges,'' the agency believes ''very significant damage is expected to have occurred'' as a result of U.S. airstrikes at Fordo, according to a statement from IAEA Director General Rafael Mariano Grossi to the agency's board earlier this week.

The centrifuges there are ''no longer operational,'' Grossi told Radio France Internationale on Thursday.

Centrifuges are used to enrich uranium — and could eventually bring it up to weapons-grade levels, if Iran chooses to do so.

Natanz, Iran's biggest enrichment site, also houses centrifuges.

In its underground plant, the IAEA believes most if not all of the centrifuge cascades — groups of centrifuges working together to more quickly enrich uranium — were destroyed by an Israeli strike that cut off power to the site.

Its aboveground plant has also been ''functionally destroyed,'' the agency said.

Strikes also caused ''extensive damage'' at Isfahan, according to the IAEA, especially at the uranium conversion facility and the plant for making uranium metal that's vital to producing a nuclear bomb.

What the damage means for Iran's program is disputed

Much like Trump, Israeli Prime Minister Benjamin Netanyahu has said Iran's nuclear program has been brought ''to ruin.''

The Israel Atomic Energy Commission believes the recent strikes have set back Tehran's ability to develop an atomic weapon by years. Israeli officials have not said how they reached this assessment.

The DIA assessment, however, suggested that Iran's nuclear program has been set back only a few months, according to the people familiar with it.

U.S. Secretary of State Marco Rubio, speaking in an interview with Politico, limited his own evaluation to saying Iran was ''much further away from a nuclear weapon today than they were before the president took this bold action.''

Iranian Supreme Leader Ayatollah Ali Khamenei has said that Trump ''exaggerated'' the impact of the American strikes.

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Associated Press writers Sam McNeil in Brussels, Michelle L. Price and Mary Clare Jalonick in Washington, and John Leicester in Paris contributed to this report.

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