Though the Trump administration’s stated objectives in the Iran war have repeatedly shifted, U.S. President Donald Trump has consistently pointed to preventing Tehran from obtaining a nuclear weapon as a central goal. And now he’s reportedly considering an operation to extract Iran’s stockpile of highly enriched uranium (HEU) in order to accomplish that aim.
Trump has gone back and forth on this issue rapidly, so it’s difficult to determine where he stands. On March 29, for example, Trump suggested that Iran would be destroyed if it didn’t give its HEU to the United States. “They’re going to give us the nuclear dust,” Trump saidin reference to the HEU. “If they don’t do that, they’re not going to have a country,”
Then, on March 31, he seemed to signal that the HEU wasn’t high on his list of priorities at the moment, while suggesting that the stockpile is virtually unreachable because it’s “so deeply buried” and “pretty safe” after U.S. strikes on Iranian nuclear facilities last June. But the U.S. intelligence community has reportedly determined that Iran could still access the stockpile at its nuclear facility in Isfahan, despite it being under rubble.
Still, Trump did not rule out an HEU operation. “We’ll make a determination,” he said. Trump also signaled that the United States will not end the war until it’s confident that Iran cannot obtain nuclear weapons. “When we feel that they are, for a long period of time, put into the stone ages and they won’t be able to come up with a nuclear weapon, then we’ll leave,” Trump told reporters in the Oval Office.
In an interview with Reuters on April 1, Trump said Iran was now “incapable” of obtaining a nuclear weapon and that its HEU was “so far underground, I don’t care about that.” Trump said the United States will “always be watching by satellite.”
One major reason for Trump’s vacillation on the issue may be how risky an operation to get the HEU would be.
Foreign Policy spoke with former U.S. officials and top military and nuclear experts who expressed grave concerns over the potential dangers of a mission to remove the near-bomb-grade uranium. They warned that it would likely last days and involve a large number of U.S. troops operating deep inside Iran in multiple locations while facing enemy fire.
“It would be very complicated and risky. I have no doubt that the United States could do it. But, to reduce risks, you’d have to put a lot of people on the ground,” said Richard Nephew, a nuclear weapons expert at Columbia University and a former U.S. deputy special envoy for Iran.
Since the war began in late February, U.S. forces have not operated on the ground inside Iran itself. But Trump recently deployed thousands of additional troops to the Middle East, including Marines and Army paratroopers, giving him a range of potential options and raising speculation that a ground operation could be on the horizon.
Several hundred U.S. special operations forces, including Army Rangers and Navy SEALs, have also reportedly arrived in the region. Some of these commandos could potentially be used in an operation focused on Iran’s HEU, possibly in collaboration with Israeli special forces. If troops are ultimately tasked with this mission, they’re expected to face serious challenges—including trying to pinpoint where the HEU is located.
Before the 12-day war last June—which culminated with the U.S. launching major strikes on three key Iranian nuclear sites: Isfahan, Natanz, and Fordow—the International Atomic Energy Agency (IAEA) estimated that Iran had a stockpile of roughly 440 kilograms (970 pounds) of uranium enriched up to 60 percent (weapons-grade levels are 90 percent). If enriched further, that would be approximately enough material for 10 nuclear bombs, per the IAEA.
IAEA Director-General Rafael Grossi has said that while some of the HEU stockpile may have been destroyed in the June strikes, it’s “mainly” believed to be in underground tunnels at Iran’s nuclear facility in Isfahan. Satellite imagery also points to much of the stockpile being at the Isfahan complex, but it’s possible that some of the HEU is in other locations. The IAEA believes a portion of the HEU stockpile is still at Natanz, for example.
Because of such uncertainties, this would not be the type of “quick in and out” operation that the U.S. public has perhaps become accustomed to, such as the January raid that saw Venezuelan President Nicolás Maduro captured, said Jonathan Schroden, chief research officer at CNA, a Washington-based nonprofit research and analysis organization. “I don’t know how you would recover that amount of radioactive material from the rubble of a facility that housed it in a matter of hours,” Schroden said, noting that this would likely be a “much longer duration mission.”
There are a wide array of substantial logistical considerations to take into account for a potential HEU extraction operation. “You can’t just walk in and take the Isfahan stocks,” Nephew said. “They’re in tunnels, the entrances of which are buried. So, you’d have to dig them out, and you can’t do that while under fire.”
More forces and infrastructure would be needed to address the security issues and the engineering of digging out the material, Nephew said. The operation would also require demolition experts to look for traps, pilots and aircraft to transport troops and equipment to the relevant locations, experts to verify the material, close air support, and probably drone and missile defenses.
To bring in all of the excavation equipment, such as earthmovers, and to remove the HEU, the United States would likely either need to secure a local airfield—Iran’s Badr air base is around 10 kilometers (6 miles) from the Isfahan nuclear complex—or create a makeshift airstrip.
If the operation focuses on more than just Isfahan and extends to other facilities like Natanz and Fordow, the latter of which is buried deep underneath a mountain, the “complexity and difficulty goes up,” Nephew said.
While Joint Special Operations Command (JSOC)—which oversees the U.S. military’s most elite special missions units—would be at the center of an operation to secure the HEU given the specialized training required, any such mission would call for “a lot more than them” despite how “capable” they are, said Mick Mulroy, who served as deputy assistant secretary of defense for the Middle East in the first Trump administration and is now a distinguished military fellow at the Middle East Institute.
The operation might involve elements of every unit in JSOC, which includes the U.S. Army’s Delta Force and DEVGRU (formerly referred to as SEAL Team 6), plus all of the 160th Special Operations Aviation Regiment (known as the Night Stalkers), and “probably a pretty substantial conventional force to coordinate the area,” said Mulroy, who is also a retired CIA paramilitary operations officer and retired Marine.
Mulroy also emphasized that the destruction of Iran’s nuclear sites by U.S. and Israeli strikes also further complicates preparations. While the units involved have done extensive training and preparation, they have likely done so using intact replicas of Iran’s facilities and “haven’t trained on something that’s collapsed,” he said.
“It might be they get there, they’ve fought their way in, and then they’re calling in the Seabees,” Mulroy said, referring to the Navy’s combat engineers. “The engineers might be the biggest part of the success or failure of this mission,” he said.
Transportation of the HEU—which is stored in scuba tank-like cylinders and would need to be placed in specialized transport casks—while possibly facing incoming fire is also a concern. The troops involved would be prepared as far as having the proper protective equipment and knowing how to handle the hazardous material, Mulroy said, but this “doesn’t mean that it’s going to go smoothly.”
“The enemy gets a vote, and everything changes when the gunfire starts,” Mulroy said, underscoring that Iran knows the targets that the United States would be going after and can thus prepare for a fight.
Iran’s strategic military assets have been “degraded substantially,” Mulroy said, but it still has a large army. The Islamic Revolutionary Guard Corps (IRGC) and the Artesh, Iran’s regular army, have the capacity to “send mass formations at this issue” to try and “overwhelm” U.S. forces, Mulroy said, and “we might end up in a pretty precarious situation.”
The United States is no stranger to complex missions involving HEU extraction. In 1994, for example, the United States worked with the government of Kazakhstan to covertly remove HEU from that country. The operation, known as Project Sapphire, took extensive planning and had its own challenges, including brutal winter weather. But it was not conducted in an active war zone or enemy territory.
There are therefore many questions about whether the risks of a military operation to remove Iran’s HEU are worth the reward.
“You really have to focus on the risks that we’re putting this force up against. They are the best in the world, but that doesn’t mean that we should use them without serious deliberation on the risk versus the benefit, looking for alternatives,” Mulroy said.
Trump has also pushed for Iran to hand over the HEU stockpile as part of a negotiated settlement, but a diplomatic resolution to the war is far from guaranteed—and Tehran has rejected U.S. proposals so far.
Trump has warned that he will order strikes on Iran’s energy infrastructure and could order U.S. troops to seize Kharg Island, through which 90 percent of Iran’s crude oil exports flow, if an agreement isn’t reached by April 6. But the president could also feel compelled to green light an operation to secure Iran’s HEU if diplomatic efforts fall through.
Fred Fleitz, who served as chief of staff on the National Security Council in Trump’s first administration, said it’s “not necessary” for the United States to retrieve Iran’s HEU because “it may not be usable,” and “even if Iran could dig it out, they don’t have the technical capabilities to further enrich it [and] convert it into uranium metal to serve as fuel in an unfinished and unfueled nuclear device.”
“In a perfect world, it would be great if we could acquire that material, but the cost and risk to American troops, I think, is simply too high,” added Fleitz, who is now vice chair of the America First Policy Institute’s Center for American Security.
But Nephew said that he doesn’t see how the Iran war could even “remotely” be considered a U.S. national security success without either “stopping Iran from having this material” or “stopping Iran from wanting to build nuclear weapons, which probably doesn’t happen with the IRGC in charge.”
If the war ends and the HEU has not been extracted, or if Iran’s use of it has not been permanently incapacitated by “verifiably destroying its cylinders” such that Tehran “cannot collect it back up,” then “you’ve absolutely opened a door to Iran getting nuclear weapons when the drones and missiles stop flying,” Nephew said.
While the U.S. strikes last June did significant damage to major facilities, the operation did not “obliterate” Iran’s nuclear program, which Trump has misleadingly claimed, as evidenced by the remaining HEU stockpile.
Israeli Prime Minister Benjamin Netanyahu recently said that Iran no longer has enrichment capacity, but he did not provide evidence to back that claim up. But Iran, which has for years maintained that it has no desire to develop a nuclear weapon, is also not currently believed to be enriching uranium, and its capabilities were assessed by the IAEA to have been severely degraded by U.S. and Israeli strikes.
While enrichment is only one step in a complex process, and building a deliverable nuclear weapon would also take time, Iran is still thought to have the capacity to build a crude nuclear weapon within months with the material it has. The U.S. intelligence community’s annual threat assessmentreleased in March, said that before the war, Iran was working “to recover from the devastation of its nuclear infrastructure sustained during the 12-Day War,” but it did not say that Tehran was actively pursuing a nuclear weapon. Experts have also emphasized that you can’t bomb away knowledge, and Iran maintains the know-how to reconstitute its program in time.
