China Nuclear Test: US Accuses Beijing of Secret 2020 Explosion

Washington D.C. – The U.S. Government has publicly accused China of conducting a secret, low-yield nuclear test in 2020, a claim Beijing vehemently denies. The allegations, revealed on Tuesday, February 17, 2026, center around a tiny seismic event detected by a remote monitoring station in Kazakhstan in June 2020.

According to Christopher Yeaw, the assistant secretary for arms control and nonproliferation at the State Department, the event – registering a magnitude of just 2.75 – originated approximately 450 miles from China’s Lop Nur nuclear test site. “There is very little possibility that it is anything other than an explosion, a singular explosion,” Yeaw stated at an event hosted by the Hudson Institute, a conservative think tank. “It is quite consistent with what you would expect from a nuclear explosive test.”

The accusation comes at a time of heightened geopolitical tension between Washington and Beijing, and as China rapidly expands its nuclear arsenal. The Pentagon estimates China’s nuclear stockpile has grown from around 200 warheads to approximately 600, with a stated goal of reaching 1,000 by 2030. This expansion is occurring despite China’s adherence – though not ratification – to the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which prohibits nuclear testing.

Independent seismological analysis has offered a more cautious assessment. Ben Dando, head of seismology and verification at NORSAR, a Norwegian organization monitoring for nuclear tests, acknowledged the seismic signature was consistent with an explosion. However, he cautioned that the signal was weak and recorded at only one station. “I would not say that there’s really strong conclusive evidence,” Dando told NPR. “We can’t really confirm or deny whether a nuclear test took place at this point.”

The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), whose station in Kazakhstan detected the event, released a statement noting two very small seismic events occurred 12 seconds apart. However, the CTBTO added that “with this data alone, it is not possible to assess the cause of these events with confidence.”

China’s Foreign Ministry spokesperson, Lin Jian, dismissed the U.S. Claims as “completely groundless,” accusing Washington of fabricating pretexts for its own potential resumption of nuclear testing. The Chinese Embassy did not respond to a direct request for comment from NPR.

The U.S. Has not conducted a nuclear test since 1992, and China’s last official test occurred in 1996. However, both nations continue to invest heavily in maintaining and modernizing their nuclear capabilities. The U.S. Utilizes advanced computer simulations and sub-critical experiments – involving small quantities of plutonium that do not trigger a full nuclear chain reaction – to ensure the reliability of its existing arsenal. Satellite imagery suggests China has been expanding facilities at its Lop Nur test site, including the construction of new tunnels.

The allegations raise concerns about China’s intentions and its commitment to the spirit of the CTBT. Experts suggest a potential motive for a low-yield test could be to develop more sophisticated nuclear weapons, including those designed for limited use scenarios or to enhance the capabilities of hypersonic delivery systems. Tong Zhao, a senior fellow at the Carnegie Endowment for International Peace, noted that China has fewer historical nuclear tests than the U.S., potentially creating a greater need for updated testing data.

Yeaw indicated the U.S. Is considering options for responding to China’s alleged actions, including potentially increasing the number of nuclear weapons deployed on its missiles, bombers, and submarines. He also expressed hope for renewed arms control negotiations with China and Russia, but acknowledged the current geopolitical climate presents significant challenges.

The timing of these accusations also coincides with the expiration of the New START treaty between the U.S. And Russia, the last remaining major arms control agreement between the two nuclear superpowers. The treaty’s lapse has further heightened concerns about a potential new arms race.