As the United States and Russia navigate uncharted waters without a nuclear arms treaty, China’s nuclear buildup is like a storm mounting on the horizon.
Beijing has dramatically multiplied its force since Chinese leader Xi Jinping came to power in 2012. China had held its stockpile steady at around 200 since the 1970s. Now, it contains more than 600 nuclear warheads and is projected to exceed 1,000 by 2030, according to a 2025 Pentagon report.
China is moving from a land-based force to a land-air-sea nuclear triad. It now has six nuclear-weapons-capable submarines, with one at sea at all times, experts say. Breaking with its traditional second-strike nuclear posture – a modest force designed to survive a first strike and inflict unacceptable damage on a soft target like a city – it’s developing an advanced force capable of taking out enemy nuclear missiles and fighting a nuclear war.
Why We Wrote This
China is engaged in a huge nuclear weapons expansion, growing the size and capabilities of its arsenal. At a time when the will to curb nuclear proliferation is waning, this could unleash a new wave of nuclear arms competition.
“China is on the path of a massive nuclear buildup with very little transparency about the end goal,” says Tong Zhao, senior fellow with the Nuclear Policy Program and Carnegie China. This, he says, is “driving a renewed nuclear competition.”
One reason the Trump administration declined to extend the New Strategic Arms Reduction Treaty (New START) was to gain leeway to respond to China’s rapid expansion, says Dr. Zhao: “[Washington] feels the need to react.”
China’s buildup
China’s leaders remain tight-lipped about their intentions for the nuclear arms expansion, but experts say one overarching objective is clear: A more powerful China.
“Xi Jinping wants China to be strong,” says Jeffrey Lewis, distinguished scholar of global security at Middlebury College. “The Xi Jinping vision is to have a nuclear force that looks more like Russia and the United States,” which currently control an estimated 86% of the world’s nuclear warheads.
China traditionally maintained a comparatively modest force, and reaching a broad parity with the U.S. and Russia would take time. But Beijing is concerned that if China appears weak, that could embolden U.S. aggression, experts say.
“President Xi wants a larger nuclear arsenal to counter America’s perception of Chinese strategic inferiority,” Dr. Zhao says.
In a public show of force, Mr. Xi presided over a huge military parade in Beijing in September that unveiled the People’s Liberation Army’s (PLA) newest intercontinental ballistic missile (ICBM), the DF-61. “The goal is to showcase the fast advancement of China’s strategic capability,” says Dr. Zhao.
Mark Schiefelbein/AP/File
To be sure, China’s nuclear weapons development has not been without glitches, including, most recently, widespread corruption. In recent years, Mr. Xi has overseen a major military purge that has netted several top commanders from the PLA’s Rocket Force, which controls the country’s nuclear and conventional missiles. Quality issues discovered with the lids of new silos China has been building may have contributed to the dismissals, experts say.
But it’s moving ahead swiftly enough to rattle Washington, which had initially called for China to join the nuclear arms control process in 2020 – a proposal that Beijing rejected. Now, China’s expansion threatens to fuel a new arms race.
“We are likely to see the U.S. starting to upload more warheads to missiles,” says Dr. Zhao. “This action-reaction dynamic … will have broader global implications.”
Collaboration with Russia
From the U.S. perspective, China’s nuclear buildup brings several risks, both geopolitical and technical. One major concern in Washington is that China and Russia could join forces against their common adversary, the United States.
China could then attack Taiwan, and Russia could move into Europe, “daring the United States to respond,” says Rose Gottemoeller, a former American diplomat who served as Under Secretary for Arms Control at the U.S. State Department and was the chief U.S. negotiator of New START. “That’s the absolute worst case scenario that the United States is contemplating, given what we call the ‘two nuclear peer’ problem,” she says.
China and Russia almost certainly remain too wary of each other to conduct joint nuclear planning, integrate their forces, or threaten a joint nuclear strike against the U.S., experts say. But they are increasingly collaborating on nuclear weapons technology and in signaling exercises. For example, Chinese and Russian nuclear-capable bombers have conducted joint patrols over the Sea of Japan and South China Sea to show resolve to Tokyo and Washington.
Advancing without guardrails
China’s nuclear program is advancing in several key areas that the Pentagon and U.S. analysts view as risky and destabilizing.
These include China’s development of an early warning system, which would use infrared satellites and ground-based radars to allow China to launch a counterstrike before an enemy’s first strike could even detonate. The U.S. and Russia both have this capability, known as “launch on warning,” as a legacy of the Cold War. It’s widely regarded as the most dangerous nuclear posture because it requires quick, life-and-death decisions – and false alarms are common, experts say. In 2019, Russia confirmed it was working with China to develop an advanced missile attack early warning system. “Those systems mean that political leaders have only a few minutes to make the most consequential decision in human history,” says Dr. Lewis. “I’m definitely worried about China joining that club.”
Another concern is the orbital bombardment system that China tested in 2021, which would allow it to launch a nuclear warhead and strike with very little warning. “China could use this weapon to conduct surprise attacks on the American leadership or [its] nuclear command and control system,” says Dr. Zhao.
China is also focused on developing dual-capable forces – missiles that can deliver either nuclear warheads or conventional warheads. In wartime, ambiguity over whether an attack is nuclear or conventional “poses all kinds of problems for keeping the nuclear genie in the bottle,” says Dr. Lewis.
The Trump administration this month accused China of conducting explosive nuclear tests, an allegation Beijing denied as “groundless.”
As China marches forward in expanding its nuclear arsenal, it has little interest in entering into talks about arms control or reducing nuclear risks. And the recent expiration of New START, which Beijing called “regrettable,” frees the U.S. and Russia to modernize and expand their own arsenals – further reducing international political pressure to restrain China.
Yet on a positive note, Ms. Gottemoeller says, Mr. Trump has endorsed U.S. nuclear experts to stay engaged with Russian counterparts. Igor Korotchenko, editor of the Moscow-based National Defense Magazine and a leading Russian military expert, says that Russia is ready to resume talks in the old format, or to find some formula for extending the New START limits. Russia’s primary concern is Mr. Trump’s desire to build a “Golden Dome” anti-
missile shield, which would undermine the Russian deterrent and make any form of arms control obsolete, he says.
Moreover, President Trump will have four opportunities to meet with Mr. Xi this year. “There’s a lot of opportunity in 2026 for the U.S. and Russia, and separately the U.S. and China, to come together and talk about reducing nuclear risks and improving nuclear controls,” says Ms. Gottemoeller.
■ Fred Weir contributed to this story from Moscow.
