A House briefing from Trump administration officials on last weekend’s strikes against Iranian nuclear sites has done little to mollify the concerns of Democrats, who say they were presented little evidence that the attacks will prevent Tehran from producing nuclear weapons.

Skeptical Democrats had gone into the briefing with two pressing questions: Did Iran pose an imminent threat to Americans, thereby justifying Trump’s move to launch the strikes without congressional approval? And did the attacks “obliterate” Iran’s capacity to make nuclear weapons, as Trump has claimed?

Leaving the closed-door gathering, Democrats said they got satisfactory answers to neither. 

“I would say that that particular briefing left me with more concerns and a true lack of clarity on how we are defining the mission and the success of it,” said Rep. Katherine Clark (Mass.), the Democratic whip. 

Rep. Bill Foster (D-N.J.), a former nuclear physicist, said the U.S. strikes likely knocked out Iran’s centrifuges and other infrastructure required to enrich uranium in the future. But there’s no evidence, he said, that the attacks destroyed Iran’s existing stockpiles of enriched uranium. If those are intact, he warned, Iran could still produce weapons with the strength of a Hiroshima bomb in “a very small break-out time.”

“I was very disappointed that we learned very little about the inventory of high-enriched uranium — 60 percent enriched uranium —  its whereabouts and what that meant for the breakout time to Iran’s first nuclear device,” Foster said. “The 60 percent-enriched material, while not weapons-grade, is weapons-usable. The Hiroshima device was a mixture of 50 percent and higher enriched uranium. And that worked pretty well.”

“The goal of this mission, from the start, was to secure or destroy that material,” he continued. “That’s where they’re hiding the ball. And that’s what we have to keep our eyes on.”

Friday’s House briefing came six days after Trump ordered strikes on three Iranian nuclear sites in an effort to dismantle Tehran’s ability to produce nuclear weapons. The briefing was conducted by top administration officials — including Defense Secretary Pete Hegseth, CIA Director John Radcliffe and Secretary of State Marco Rubio — who had also briefed Senate lawmakers a day earlier.

Tulsi Gabbard, the director of national intelligence who has clashed with Trump over the threat of Iran’s nuclear program, did not attend either briefing. 

Trump has repeatedly said the mission was an unqualified success, “obliterating” Iran’s nuclear capacity and setting the program back by years. And the president’s GOP allies in the Capitol echoed that message after the briefing.

“It is clear, everyone can see by the videos, that these massive ordinance penetrating bombs did the job,” said Speaker Mike Johnson (R-La.). “I think their key facilities have been disabled and I think Iran is now a long time away from doing what they might have done before this very successful operation.” 

A preliminary report from the Pentagon’s Defense Intelligence Agency (DIA) reached different conclusions, finding that the strikes set back Iran’s nuclear program by months, rather than years. More recent statements from the CIA and Trump’s head of national intelligence have disputed the DIA report, creating mixed messages from the administration about the success of the mission. 

Republicans are siding clearly with the latter. 

“You can dismiss the low-level initial assessment, and you can rely upon what the CIA has said, because these are first-hand accounts,” Johnson said. 

“The greatest evidence that we have of the effectiveness of this mission was that Iran came immediately and was willing to engage in a ceasefire agreement,” he added. “That would have been unthinkable just a few weeks back.”

Indeed, Trump said Wednesday that administration officials will meet with Iranian officials next week, when the U.S. will press Iran on ending its nuclear ambitions. 

At least one prominent Democrat, for his part, did air some satisfaction with the briefing: Rep. Jim Himes (Conn.), the top Democrat on the House Intelligence Committee, said Rubio clarified that the objective of the mission “was to set back or destroy Iranian nuclear capability in the service of bringing them to the table.”

But whether that goal was achieved remains an open question. Himes said that even though the U.S. wants to bring Iran back to the negotiating table, it does not mean Tehran will follow suit.

“There’s two questions: Did we, in fact, set back or destroy? And two, Will they come to the table?” Himes said. “It’s really too early to tell what the intentions of the Iranians are. If the intentions are to go to the negotiating table, great. 

“But the intentions may also be to just go underground and produce a device.”