In a significant address to the UN Conference on Disarmament in Geneva, U.S. arms control official Christopher Yeaw revealed newly declassified intelligence alleging Chinese nuclear testing activities. The disclosure comes amid heightened global tensions following the expiration of the last nuclear arms pact between the United States and Russia earlier this month.
Yeaw, serving as assistant secretary of state for arms control and nonproliferation, presented detailed seismic data indicating a probable nuclear explosion at China’s Lop Nur underground testing facility on June 22, 2020. The event registered as a magnitude 2.75 seismic disturbance, detected by international monitoring stations in neighboring Kazakhstan. According to Yeaw’s analysis, the seismic signature matched historical patterns of explosive testing rather than natural earthquakes or conventional mining operations.
The timing of these allegations coincides with growing international concern about nuclear proliferation. With the New START treaty now expired, the world’s two largest nuclear powers face no constraints on their arsenals, while China continues its rapid nuclear expansion. Yeaw criticized both China and Russia for their lack of transparency, particularly highlighting that China may achieve nuclear parity with the United States within the next four to five years.
Chinese Ambassador Jian Shen vehemently denied the allegations, characterizing them as “completely unfounded” and accusing the United States of using false claims as pretext to resume its own nuclear testing program. Shen emphasized China’s continued adherence to the Comprehensive Nuclear Test Ban Treaty commitments and dismissed calls for three-way arms control talks as “unfair, unreasonable and unfeasible” given the disparity in nuclear arsenal sizes.
The diplomatic confrontation occurs against the backdrop of failed U.S. efforts to establish a trilateral nuclear agreement involving China during the Trump administration. Current Secretary of State Marco Rubio has indicated continued pursuit of diplomatic solutions through bilateral, small-group, or broader multilateral approaches to address what U.S. officials describe as China’s “unprecedented, deliberate, rapid and opaque nuclear weapons buildup.”