When three villagers from China’s Sichuan province wrote to local officials in 2022 asking why the government was confiscating their land and evicting them from their homes, they received a terse reply: It was a “state secret.”
That secret, a CNN investigation has found, centered on China’s covert plans to massively expand its nuclear ambitions.
More than three years after the evictions, satellite images show, their village has been flattened and, in its place, new buildings erected to support some of China’s most important nuclear weapons production facilities.
The expansion of the sites in Sichuan province, observed in satellite imagery and a review of dozens of Chinese government documents, supports recent claims by the administration of US President Donald Trump that Beijing has been conducting its most significant nuclear weapon modernization campaign in decades.
Trump is set to visit Beijing on a landmark trip next month where he is expected to try to begin a dialogue about a deal to curb Chinese leader Xi Jinping’s nuclear ambitions. Earlier this year, the latest arms reduction agreement between Russia and the United States – known as New START – expired, with Trump wanting to strike a new and improved deal with Moscow that would also include China.
But the dramatic changes seen at sites in Sichuan suggest that the nuclear weapons development of China’s military, known as the People’s Liberation Army (PLA), shows little sign of abating.
One of the most substantial additions to the area is an enormous dome, unusually shaped like a Tic Tac, emerging from the banks of the Tongjiang River in less than five years. It appears to continue to be outfitted with equipment, suggesting it may not yet be in use.
At 36,000 square feet – the size of 13 tennis courts – the reinforced dome is enclosed by a concrete and steel structure with radiation monitors and blast doors, its network of pipes snaking out of the facility and into a building with a tall ventilation stack. These and other features, including extensive air handling equipment, are designed to keep highly radioactive materials such as uranium and plutonium trapped inside the dome, according to multiple experts.
The facility, which was built inside a nuclear weapons base long known to the CIA, is encircled by three layers of security fencing. A nearby tunnel disappears into the side of a mountain. To analyze individual features of the site known as 906, CNN compiled more than 50 snapshots from different phases of the facility’s construction into a 3D model.
“This building is almost a Rorschach test for people’s worst nightmares about what China is up to,” said Jeffrey Lewis, a distinguished scholar of global security at Middlebury College, one of three experts who reviewed CNN’s findings.
“You’re looking at a reconfiguration of this complex,” Lewis added, referring to the network of nuclear weapons sites in and around Zitong county. “This facility is a centerpiece. It is emblematic of all these changes. It does seem that there’s going to be a much bigger capacity to produce at the end of this.”
Newly refurbished roads link Site 906 to at least three other nuclear weapons bases strung along narrow valleys in and around Zitong county. The construction project of the dome facility inside 906 was designated XTJ0001, according to Chinese government documents reviewed by CNN.
Another of these production facilities is Site 931, which expanded into Baitu village, prompting the evictions of its inhabitants. The nearby village of Dashan was also torn down to make way for the development of the base.
A road to rail transfer point connecting the network to the west of the country has also been dramatically overhauled since 2021 – another telltale sign of a comprehensive revival of the Zitong facilities.
When spy satellites first captured images of the Zitong network in 1971, US intelligence deemed the sites a gamechanger. Declassified documents concluded that they set Beijing on course to become the world’s third largest producer of the deadly warheads.
This prediction bore out around 2020, when China’s warhead stockpiles overtook those of France. Beijing is the fastest producer of nuclear weapons in the world, according to the Pentagon, though, with just over 600 warheads, it continues to trail far behind the US and Russia, each of which commands a stockpile at least four times the size of China’s.
In February, Undersecretary of State for Arms Control Thomas DiNanno accused China of having violated a ban on explosive nuclear testing. Beijing vehemently denied that claim.
US intelligence officials also assessed that Beijing had been testing a new generation of nuclear warheads.
Chinese defense ministry spokesman Jiang Bin said those remarks “distort facts and smear China.”
“It is known to all that China pursues a nuclear strategy of self-defense and follows a nuclear policy of no first use of nuclear weapons,” Jiang said. “China pledges not to use or threaten to use nuclear weapons against non-nuclear-weapon states and nuclear-weapon-free zones.”
But unusual designs of some of the facilities, such as that of the Zitong River dome, lend some credence to DiNanno’s claims that China is overhauling its nuclear weapons program.
“It might be that there are new processes being established at these locations, new types of things being made,” said Renny Babiarz, vice president of Analysis and Operations for AllSource Analysis, who reviewed satellite imagery for CNN.
“It’s clear that there are a lot of changes happening on the ground.”
Those developments may have created blind spots for Western adversaries. “It used to be that we could make some educated guesses about how many nuclear weapons the Chinese could produce,” said Decker Eveleth, a nuclear and deterrence analyst at CNA Corporation, who also reviewed CNN’s findings.
“The fact that this modernization is so extensive suggests a fundamental overhaul in the technology that underlies the entire system.”
Further supporting the contentions of a modernization drive is a massive overhaul seen in a collection of research institutes some 40 miles southwest of the Zitong network. The area, known as Science City, is considered the brains of China’s nuclear weapons program.
The growth of the campuses is so extensive that over 600 buildings were torn down to make way for the facilities in 2022, according to satellite imagery.
Asked about CNN’s findings, the Chinese Ministry of Foreign Affairs said: “We are not aware of the situation you mentioned.” The Chinese Ministry of Defense did not respond to requests for comment.
The comprehensive, ongoing change around Zitong county began in 2021, according to CNN’s analysis. This came just a few months after Xi publicly instructed his military top brass to “accelerate the construction of high-level strategic deterrence.”
Beijing’s nuclear weapons posture has become more muscular. China has developed early warning systems, according to the Pentagon, allowing it to detect an incoming missile and fire before it impacts.
In the case that the PLA launches an invasion of Taiwan, the self-ruled island which Beijing claims as its own, China’s bolstered arsenal is likely to act as a deterrent against Western forces that may come to Taipei’s aid.
It is also a lynchpin of Xi’s vision of a diplomatically empowered China.
“(China’s) leadership appears to believe that to build and demonstrate strategic capability, including nuclear weapons, can have a psychological impact on Western countries,” said Tong Zhao, a senior fellow at the Nuclear Policy and China program at the Carnegie Endowment for International Peace.
“And to compel them to accept the reality of a rising China.”
There are fears that the seemingly unfettered growth of China’s arsenal could spark a new arms race, more complex than the Cold War because Beijing would act as a third major nuclear power.
In such a scenario, the size of a warhead stockpile may prove immaterial, argued Eveleth. “Once you get past a certain number of warheads it becomes an academic distinction,” he said. “It’s about the capabilities and what you’re planning to do with them more than it is about the number of warheads.”
There are also concerns that the US may overestimate China’s capabilities, exacerbating nuclear proliferation.
“There will be people in the US who will argue that we need to radically expand our own ability to produce nuclear weapons to match China,” Lewis said. “But we’re not going to match what they’re doing. We’re going to match what we think they’re doing. We’re going to match our own nightmare. And that’s potentially very dangerous.”
Meanwhile, Trump may find himself in a bind in Beijing. China’s infrastructure – and Xi’s increasingly consolidated rule over its military as evidenced by recent purges of top generals – gives it some advantage in the event of an arms race, and Beijing may see little reason to concede.
The US and Israel’s ongoing war on Iran may have hardened China’s resolve to expand its nuclear weapons program, experts say.
“If you are the Chinese… in hindsight, you don’t look at what’s happening and think it makes sense to disarm or get weaker,” Lewis said.
“One consequence of what the Trump administration is doing in Iran is not going to be to cow or intimidate the Chinese, but it will be to frighten them into building more nuclear weapons,” he added.
In case the US makes concessions on core strategic issues such as Taiwan, Xi may “make a symbolic commitment to launching a broad bilateral strategic security dialogue in which nuclear issues would be one component,” Zhao said.
“Even in this optimistic scenario, Beijing would be unlikely to pursue any serious arms control negotiations,” he added. “But its willingness to initiate a broad-based dialogue could be sufficient to satisfy Trump.”
Methodology
CNN reviewed dozens of satellite images, Chinese government documents and declassified US intelligence reports to produce this story. We identified China’s key nuclear weapons research institutes and production bases – all located in and near Mianyang city, Sichuan province – then determined their locations, code names and functions by comparing against official records. We further examined satellite imagery to confirm the expansion and upgrade of these facilities over the past five years. Following this, we consulted several of the world’s leading non-government experts on China’s nuclear weapons program to better understand the roles of these sites in the country’s nuclear weapons strategy.
We placed particular focus on Site 906, which has undergone the most dramatic overhaul among the known facilities. By comparing tender notices published by the lead construction company and the China Academy of Engineering Physics (CAEP), we determined that this site is intended to handle radioactive materials for nuclear weapons research and development.
In addition to these production sites, we identified 10 CAEP research institutes in Mianyang via official information, and found six of these have seen significant recent expansion. Due to limited open-source information available on these specific institutes, we were unable to determine the exact function of each one. However, based on collective evidence showing major expansion of both research and production facilities, we concluded that China is systematically upgrading its nuclear weapons program.
CREDITS:
Senior Investigative Reporter/Writer: Tamara Qiblawi
Investigative Reporter/Producer: Thomas Bordeaux
Investigative Producer: Yong Xiong
Supervising Visual Investigations Editor: Gianluca Mezzofiore
Data and Graphics Editors: Lou Robinson and Annette Choi
Senior Visuals Editor: Gillian Roberts
Supervising Producer: Barbara Arvanitidis
Supervising Editor, Enterprise: Boer Deng
Senior Video Editor: Oscar Featherstone
Supervising Investigative Editor: Tim Elfrink
Managing Editor, Investigations: Matt Lait
