What a US Nuclear Strike on Iran’s Pickaxe Mountain Could Look Like - Newsweek

President Donald Trump has threatened many times that the U.S. could attack Pickaxe Mountain, the secretive granite-swathed underground facility linked to Iran's cloaked nuclear weapons program.

"It's not a big deal," he remarked earlier this week. U.S. operations could be done in as little as one hour, he suggested.

But the U.S. did not strike the site during the brief war in June 2025, nor in the months of assaults carried out with Israel from late February 2026.

Some estimates put the heart of Pickaxe Mountain as far as 100 meters (nearly 330 feet) underground—meaning even the most destructive non-nuclear U.S. bombs, such as the GBU-57 Massive Ordnance Penetrator, or "bunker busters," would be hard-pressed to destroy it.

Conservative commentator and former Fox News host Tucker Carlson said on Sunday—without providing evidence—that the U.S. government was weighing up a nuclear strike on Pickaxe Mountain.

"[T]he Trump administration may be within days of launching a nuclear strike on Iran," he wrote on social media. The White House said the former Trump ally had "no insight into military planning" or the president's thinking.

While unlikely, if Trump did greenlight the first use of a nuclear bomb since the American attacks on the Japanese cities of Hiroshima and Nagasaki in 1945, analysts say it could encourage other nuclear powers to deploy their atomic arsenals while spurring others to chase nuclear capabilities and further radicalizing Iran's hardline factions.

But Carlson's claims raised the question: Just how far would the U.S. go to take out Pickaxe Mountain, and would it need to resort to a nuclear strike to get the job done?

The U.S. has the world's second-largest nuclear arsenal, after Russia. It has both strategic nuclear weapons—generally thought of as able to level entire cities—and tactical nuclear weapons, which have a lower yield and comparatively less destructive power.

For a targeted military strike like on Pickaxe Mountain, the U.S. wouldn't use its strategic weapons, such as its nuclear-armed intercontinental ballistic missiles.

Instead, it is more likely to use a tactical nuclear weapon, although any form of nuclear strike remains very unlikely. The U.S. has an estimated 200 B61 gravity bombs, half of which are deployed in bases across Europe. They can be launched from fighter jets like the F-35A.

The U.S. is rolling out the upgraded B61-13, which is designed to blast apart well-defended targets. Only strategic bombers can carry the B61-13, which has a yield of up to 360 kilotons—around 24 times the yield of the bomb dropped on Hiroshima.

Hypothetically, the U.S. could drop several GBU-57s on Pickaxe Mountain, opening up the way for a follow-up tactical nuclear strike with a B61 gravity bomb.

The 30,000-lb precision-guided weapons would first dig into the mountain side, meaning the nuclear explosion that follows would have maximum impact but hopefully minimal fallout, said William Alberque, a former head of NATO's nuclear non-proliferation center currently with the Pacific Forum nonprofit.

In June 2025, U.S. B-2 Spirit bombers dropped 14 GBU-57s on Iran's Fordow and Natanz nuclear sites, but not on Pickaxe Mountain. It was the first-ever combat use of the GBU-57.

To successfully attack Pickaxe Mountain, the U.S. would need excellent intelligence sources and meticulous modeling, experts say.

But little is publicly known about the design of the facility inside Pickaxe Mountain, including whether it has multiple levels. Unlike with other Iranian nuclear sites, schematics for the facility aren't available, according to the Institute for Science and International Security (ISIS).

This complicates the already ambitious task of attempting to take out the buried site—on top of any nuclear strike being unlikely to rip apart Iran's entire nuclear program or stand a chance of obliterating its remaining stockpile of highly enriched uranium.

"Destroying Pickaxe Mountain will be a scientific and targeting challenge," the U.S.-based Center for Strategic and International Studies (CSIS) said in September. "It is an underground fortress buttressed by granite."

Pickaxe Mountain sits a little over a mile from Natanz, which is Iran's main uranium enrichment facility. Tehran's then-nuclear chief, Ali Akbar Salehi, said in 2020 Tehran was piecing together a vast, "modern" hall for centrifuges "in the heart of the mountain" near Natanz after an explosion damaged a previous facility in a potential act of sabotage.

Centrifuges are used to enrich uranium for both peaceful nuclear power and for nuclear weapons. Weapons-grade uranium is generally considered to be above 90 percent, while civilian projects typically use uranium enriched up to little over 3 percent.

The United Nations' nuclear watchdog said that by mid-2025, Iran had enriched roughly 440 kilograms (nearly 1,000 pounds) of uranium to 60 percent, which is just a short scientific jump to the level needed to make a nuclear bomb and far above what is needed for civilian nuclear power.

A Wall Street Journal report in July said Israeli intelligence told U.S. officials Iran had moved centrifuges into Pickaxe Mountain last fall, shortly after the 12-day war in June 2025.

Satellite imagery has indicated internal work on Pickaxe Mountain has continued in the almost year and a half since that brief conflict, but analysts say Iranian scientists are probably not enriching uranium while construction is still underway.

The prospect of a U.S. nuclear strike prompts concern and consternation among observers and campaigners. It would be "extremely counterproductive, illegal, and it would, among other things, lower the threshold for nuclear weapons use by others in the months and years ahead," said Daryl Kimball, the executive director of the U.S.-based Arms Control Association (ACA)

The president is the only U.S. official able to authorize a nuclear strike. Top military leaders provide information and advice, but they do not need to approve nuclear weapons use, and neither does Congress.

If the U.S. did drop a nuclear bomb on Iran, it would "incentivize some countries that do not currently have nuclear weapons to acquire them," said Reid Pauly, an assistant professor of political science and expert in nuclear security and policy at Brown University.

"Using a nuclear weapon against Iran would be catastrophically stupid," Pauly told Newsweek.

Three NATO members, including the U.S, have nuclear weapons, with nine states across the globe believed to possess nuclear warheads.

If Trump did authorize a nuclear assault. countries like South Korea, Saudi Arabia and NATO member Turkey may mull over whether becoming a nuclear power is the best way to protect themselves, said Alberque. Even Japan, despite its excruciating history with the atomic bomb, could consider acquiring nuclear weapons, he added.

The consequences would be seismic. It would rip apart longstanding NATO dynamics, threaten the U.S.'s position on the U.N. Security Council and would kill the decades-old Non-Proliferation Treaty (NPT) signed by 191 countries, that stops more countries getting access to nuclear weapons and promotes disarmament, said Alberque.

Some speculate it may also be taken as implicit permission for Russian President Vladimir Putin to deploy Russia's vast nuclear arsenal against Ukraine—or for China's Xi to keep Beijing's own nuclear warheads on the table in any confrontation with Taiwan.

Much like the White House with Iran, Russia has become mired down in a grinding, unpopular war it thought would be finished and won within mere days. The Kremlin has already fired the nuclear-capable—not nuclear—Oreshnik intermediate-range ballistic missile at Ukraine.

"Is it likely that Trump actually orders a nuclear strike against Iran? No," added Kimball. "Is it possible that an unstable, desperate president who has sole authority to authorize nuclear weapons use, would do so, yes."

Nuclear weapons use during war would be governed by laws of armed conflict, or international humanitarian law (IHL). Nuclear attacks are judged by the same criteria as conventional strikes, meaning they are unlawful if, for example, deemed out of proportion or deliberately targeting civilians.

Human rights groups opposing nuclear weapons argue that laws banning indiscriminate and disproportionate attacks mean that, by their nature, nuclear weapons contravene IHL.

Pickaxe Mountain would need to qualify as a military target, and a site used for civilian uranium enrichment or centrifuge production does not automatically fulfil this criteria, said Marco Roscini, a professor of international law at the University of Westminster, U.K.

"If the facility qualifies as a military objective, if the expected incidental civilian harm would not be excessive in relation to the concrete and direct military advantage anticipated, and if no less harmful means of attack could reasonably achieve a comparable military advantage, a nuclear strike might potentially comply with the main IHL targeting rules," Roscini told Newsweek.

American soldiers are obligated through the Uniform Code of Military Justice “to follow orders provided they are legal and have come from competent authority.”

Trump last month ruled out using nuclear weapons against Iran, while referring to the GBU-43—sometimes nicknamed the "mother of all bombs"—an "extremely large" non-nuclear bomb.

But rather than being ground penetrating, the GBU-43 is an air-blast weapon which makes surface-level explosions, rather than being effective against buried targets.

In April 2017, during Trump’s first term, the U.S. dropped this very bomb on an Islamic State tunnel complex in Afghanistan. It was the weapon’s first combat use and remains the most powerful conventional blast bomb used by the U.S. in combat.

Rather than opting for a nuclear strike, the U.S. could launch a sustained campaign of bombardment using GBU-57s, Alberque said. But repeated strikes would likely mean U.S. airplanes would spend more time over Iranian airspace, risking being targeted by its remaining air defense systems.

The U.S. could also choose to employ sabotage tactics or send in ground forces to attack the site, the ISIS analysts say. Another option could be cutting power supply lines, or blocking ventilation to the underground areas, while the CSIS has argued the Pentagon could hit the tunnel entrances with cruise missiles, rather than trying to take out the underground facility.

When the U.S. struck the Isfahan underground site in June 2025, it used Tomahawk cruise missiles to collapse the entrances.

Contact Newsweek editors on this story: Ben Kelly and Yannick Demoustier.