Among the Iranian nuclear facilities the U.S. reportedly targeted in Sunday morning’s attack was the Pickaxe Mountain Facility. Iran has not acknowledged the site’s development or construction and it has retained a lower public profile, with the Institute for Science and International Security first discovering its existence in 2023. 

The facility, just south of the Natanz nuclear facility and buried roughly 330 feet below the mountain itself, was particularly concerning to experts due to its depth, which is between 30 to 70 feet deeper than Fordow. This is said to exceed the striking depth of the most powerful bunker-busting weapons in the U.S. arsenal.

Recent Iranian announcements stating the government planned to open a new facility heightened fears that Iran could take the site online in the near future, according to Andrea Stricker, the deputy director of the nonproliferation and biodefense program at the Foundation for Defense of Democracies.

“There’s concern that Iran was creating the floor space for another secret enrichment facility,” Stricker told Jewish Insider. “And so when the [International Atomic Energy Agency] Board of Governors passed a resolution finding Iran in non-compliance with the Nuclear Non-Proliferation Treaty a couple of weeks ago, the Iranians threatened to build another or to open another enrichment facility, and people immediately feared that this would be the site of it.”

An additional concern over the potential opening of Pickaxe Mountain was that Iran had previously refused to give notice of new nuclear facilities, as required by agreements Iran had signed with the IAEA. According to Stricker, this meant that Iran might begin operations at the plant without notifying the international community, which may have been a factor in Israel’s decision to launch its current operation against Iranian nuclear and military facilities.

Sen. James Lankford (R-OK) cautioned on Tuesday that bombing Iran’s underground Fordow nuclear facility would leave significant enriched uranium buried underground.

“I’m a little confused on all the conversation about dropping a bunker buster on a mountain that’s filled with enriched uranium, and how that solves the problem. If you’re going to try to get enriched uranium out of the country, dropping a big bunker buster on it may disable the centrifuges in [Fordow], but you still have 900 pounds of enriched uranium sitting there,” Lankford told Jewish Insider. “And so to me, the most strategic thing we can do is find a way to get that enriched uranium out of there and also take out their capacity to do any more enrichment.”

He added that such an operation could be “[with Iran’s] consent [through a deal] or kinetic [military operations], one or the other.” Most experts believe that Israel lacks the ability to destroy the Fordow facility without U.S. assistance.

“They can’t have that level of enriched uranium sitting there in those centrifuges, all spinning, but just burying that uranium inside the mountain, I think, doesn’t solve the problem either,” Lankford continued.

Andrea Stricker, the deputy director of the nonproliferation and biodefense program at the Foundation for Defense of Democracies, said that the risk from nuclear materials remaining at Fordow after an Israeli or American strike would be minimal.

“If the Israelis target Fordow they would likely render it, for all practical purposes, inaccessible. The highly enriched uranium stocks could survive but would be very difficult for the Iranians to reach,” Stricker told JI. “The United States using the 30,000-pound massive ordnance penetrators would effectively destroy the material or entomb it inside. “

She added that there is “little concern about a major radiological incident in either case. Any radiation and chemical hazard would be minimal and localized to the facility, requiring people to wear protective gear.”

She compared the possibility to the Israeli strikes on above-ground facilities at Natanz, where the International Atomic Energy Agency reported no significant concerns about radiological contamination outside the site.

Asked about whether the U.S. should be pushing for regime change in Iran, Lankford said that “the best thing that could happen is regime change there,” but did not endorse the idea of using U.S. forces to achieve that goal. President Donald Trump suggested on Tuesday that the U.S. could kill Iran’s supreme leader, Ayatollah, Ali Khamenei.

“This is a regime that chants, over and over, ‘Death to America. Death to Jews.’ And they’ve actively worked towards assassinating President Trump, assassinating former members of our cabinet, working for the undermining of the United States government, attacking our warships through the Houthis off the coast of Yemen,” the Oklahoma Republican said. “We need to see regime change there because I’m not sure things get better for the Iranian people, or for the region, until there’s new leadership with a very different vision.”

He said that while the nuclear threat is the most pressing issue, it’s hard to see how the situation will improve, how the Iranian government can ever be trusted or how the Iranian people could have better lives under the Islamic Republic regime.

Lankford said that, under war powers limitations, the U.S. military may not be able to get involved until it is attacked directly or until the administration can provide evidence that Iran is planning a direct attack on the United States or U.S. personnel, as it did for the 2020 killing of Quds Force Gen. Qassem Soleimani.

The Oklahoma senator said in a CNN interview that the U.S. should not “rush into a war” but added that “when we are attacked, when we are threatened, we can’t just sit back and pretend that’s not going to happen.”

“If 9/11 taught us anything, when people chant ‘Death to America’ thousands of miles away, that does have consequences, they can carry that out,” Lankford continued

He noted on CNN that there are also 700,000 Americans in Israel, and that what happens in the region will impact them. Lankford also said Iran is “dancing on a threshold there seeing how close they can get to attacking Americans without our response.”

Speaking to reporters on Capitol Hill, Lankford expressed support for the continued provision of U.S. aid to Israel to defend itself and carry on its military operations, and criticized colleagues who he said had not argued that additional congressional authorization was needed in order to provide U.S. support for Ukraine but are now taking a different approach to Israel.

“There seems to be a double standard among some of my colleagues that they strongly defend the rights of Ukraine to defend themselves, but hesitate on Israel,” Lankford said.