According to President Donald Trump, Iran’s nuclear program is finito. 

“Obliteration is an accurate term!” Trump wrote in a Truth Social post on Sunday. “Monumental damage was done to all nuclear sites in Iran.” He said on Monday that the three sites hit by U.S. strikes on Sunday morning “were totally destroyed, and everyone knows it.” White House Press Secretary Karoline Leavitt told reporters on Monday that the U.S. “took out” Iran’s nuclear program over the weekend.

Nuclear experts aren’t as confident. What, exactly, remains of Iran’s nuclear program — which, just weeks ago, Israeli officials said was on the precipice of being able to produce a nuclear weapon — remains an open question. (A White House spokesperson did not respond to a request for comment.) 

Experts agree that the combination of Israel’s strikes that began a week and a half ago, aided by the U.S. military’s intervention on Sunday, has done significant damage to Iran’s nuclear capabilities. But uncertainty lingers about the status of the enriched uranium that had been housed at Fordow, the major Iranian nuclear facility hidden under a mountain that the U.S. struck with bunker-buster bombs this weekend. 

Reports suggest Tehran may have removed the nuclear materials from Fordow and hidden them elsewhere in Iran. 

“I think that we can assume that damage was done, but it’s going to take a long time, and we may never know entirely the extent of the damage,” said Tressa Guenov, a senior fellow at the Atlantic Council who dealt with international security affairs at the Pentagon in the Biden administration. Iran’s claim that it moved the uranium “could be real, or it could be a strategy to keep things ambiguous,” she added. 

David Albright, a former United Nations weapons inspector, told The Free Press that “any highly enriched uranium at Fordow was likely gone before the attack.” 

Even with the possibility that the enriched uranium was moved from Fordow, experts agreed that Iran’s nuclear program has been left reeling by the Israeli and American military actions.

“Israelis believe that they dealt together with the U.S. … a really serious blow to the Iranian nuclear program, took it back by, some say, two years,” Michael Herzog, who until January was Israel’s ambassador to the U.S., said on Monday. But, he cautioned, it’s “premature to make that assessment.” Elliott Abrams, a longtime Republican foreign policy advisor who served as Trump’s special representative for Iran in Trump’s first term, said Iran is “now years away” from being able to make a nuclear weapon. 

And the extent of the damage goes beyond just the nuclear program. 

“Iran is losing its nuclear weapons option, and we have applied military force to ensure that,” said Dennis Ross, a former State Department official who worked in both Republican and Democratic administrations. “You have a military that has been decapitated. You have a Revolutionary Guard that has been decapitated. You have people in both those leaderships that have been basically together for the last 30 years. They’re not so easy to replace. You have a leadership that doesn’t know who it can trust. You have a leadership that is completely in hiding.” 

Even if Iran’s nuclear weapons program was set back several years, that is not the same thing as obliterating its ability to create a nuclear weapon, as Trump claimed. Vice President JD Vance repeated that statement several times in a Monday night interview on Fox News, where he discussed the newly announced ceasefire deal between Israel and Iran and asserted that Iran’s nuclear program was “obliterated.” 

But fully dismantling Iran’s nuclear weapons program might not even be a realistic goal.

“We know that no military operation on its own will completely eliminate the Iranian nuclear program,” Dana Stroul, a fellow at the Washington Institute for Near East Policy who oversaw Middle East policy at the Pentagon in the Biden administration, said earlier Monday.

During the war, Israeli officials hinted that they want to see regime change in Iran. Yet by announcing the ceasefire on Monday night, the Trump administration underscored that the goal of its military operation was to set back Iran’s nuclear program, and not target Iran’s leadership. 

“Absent a revolution in Iran that brings in a friendlier regime, where you could verify the moth-balling of [nuclear] sites and this dismantlement of the program, I don’t think you could ever say for certain that the program is over,” Steven Cook, a senior fellow at the Council on Foreign Relations, told Jewish Insider on Monday. 

Trump said in a Truth Social post on Monday evening that, once the fighting ceases, “the War will be considered, ENDED,” and that both sides “will remain PEACEFUL and RESPECTFUL.” He did not share whether either side had to abide by any particular demands, or whether the agreement would mark a return to the negotiating table.