Seldom have accusations at an international forum carried such profound implications for global security. On February 6, 2026, US Undersecretary of State Thomas DiNanno addressed the Conference on Disarmament in Geneva. He alleged that China had conducted a covert nuclear explosive test on June 22, 2020. Furthermore, he claimed Beijing had employed decoupling techniques to conceal the detonation from seismic monitoring systems.
The allegations surfaced at a particularly volatile juncture in nuclear diplomacy. The New START Treaty, the last binding arms control agreement between the US and Russia, expired on February 5, 2026. Its expiration left the world's largest nuclear arsenals unconstrained for the first time since 1972. Washington argued that a bilateral treaty with Russia alone was no longer sufficient to address modern threats.
China has categorically rejected the accusations, maintaining its adherence to a nuclear testing moratorium. The Chinese Embassy spokesperson reaffirmed Beijing's longstanding policy of no first use and a defensive nuclear strategy. Meanwhile, the Comprehensive Nuclear-Test-Ban Treaty Organization stated its monitoring system detected no event consistent with a nuclear test. This discrepancy between the US claims and international monitoring data has generated considerable scepticism.
The Trump administration has advocated for a new, multilateral treaty encompassing both China and Russia. DiNanno warned that China's nuclear warheads now number approximately 600 and are increasing by roughly 100 annually. US projections suggest China could possess over 1,000 warheads by 2030. Such a rapid proliferation underscores the urgency of establishing a comprehensive arms control framework.
Security analysts caution that any new nuclear agreement will likely take years to negotiate. China has thus far rebuffed calls to participate in trilateral disarmament talks, citing its comparatively smaller arsenal. The vacuum left by expired treaties and unsubstantiated allegations risks fuelling an unmitigated nuclear arms race. Whether diplomacy can prevail over escalating distrust remains an open and consequential question.
