China's secret nuclear expansion: New warhead facilities detected in Sichuan mountains

In the mist-covered valleys of southwest China’s Sichuan Province, satellite imagery is revealing a rapid expansion of the country’s nuclear weapons infrastructure, part of what experts say is a broader effort to strengthen China’s position in an era of intensifying superpower rivalry.

These secretive nuclear-related sites, including facilities near Zitong and Pingtong, have expanded and been upgraded in recent years. Analysts say the changes fit a wider national push to modernize China’s nuclear arsenal, complicating efforts to revive global arms control after the expiration of the last remaining US-Russia nuclear treaty. Washington argues that any future agreement must also include China, but Beijing has shown no interest.




According to the Pentagon’s latest estimate, as reported by The New York Times, China possessed more than 600 nuclear warheads by the end of 2024 and could reach 1,000 by 2030. Although that total remains far below the stockpiles of the United States and Russia, analysts say the pace of growth is concerning.

“I think without a real dialogue on these topics, which we lack, it’s really hard to say where it’s going, and that, for me, is dangerous,” said Matthew Sharp, a former State Department official now at the Massachusetts Institute of Technology. “Because now we’re forced to react and plan around the worst-case interpretation of a concerning trend line.”

One valley lies near Zitong, where engineers have been constructing new bunkers and ramparts. A newly built complex there is threaded with pipes, suggesting it handles highly hazardous materials. Another valley houses a heavily secured site known as Pingtong, where specialists believe plutonium cores for nuclear warheads are produced.

The main structure at Pingtong, marked by a 360-foot ventilation stack, has been refurbished with new vents and heat dispersers, and further construction is underway nearby. Above the entrance, large characters bearing leader Xi Jinping’s slogan—“Stay true to the founding cause and always remember our mission”—are visible from space.

Experts say Pingtong’s layout resembles plutonium pit production plants in other countries, including the Los Alamos National Laboratory in the United States. At Zitong, the new bunkers and fortified areas are likely used to test high explosives — the chemical charges that compress nuclear material to trigger a chain reaction.

“You have a layer of high explosives and the shock wave at the same time implodes into the center. This needs blast tests to perfect them,” said Hui Zhang, a physicist at Harvard University who reviewed the findings, as quoted by NYT.

The precise purpose and scale of the upgrades remain uncertain. “We don’t know how many warheads have been produced, but we just see the plant expansion,” Zhang said. Some changes could reflect safety improvements or preparations to adapt warhead designs for new weapons systems such as submarine-launched missiles.

“The changes we see on the ground at these sites align with China’s broader goals of becoming a global superpower. Nuclear weapons are an integral part of that,” said Renny Babiarz, a geospatial intelligence expert who analyzed satellite images of the locations. “There’s been evolution at all of these sites, but broadly speaking, that change accelerated starting from 2019,” he said.

US officials worry that a larger and more advanced arsenal could affect China’s actions in a future crisis, especially over Taiwan. China seeks to ensure it is “in the position where they believe they’re largely immune from nuclear coercion by the United States,” said Michael S Chase, a former Pentagon official now at RAND. “I think they probably judge that could come into play in a conventional conflict over Taiwan.”