US-China nuclear testing and arsenal dispute

The United States has initiated confidential diplomatic discussions with China regarding allegations of covert low-yield nuclear testing and a rapid expansion of China’s strategic nuclear arsenal. US officials have expressed concerns that China may be violating the 1996 Comprehensive Nuclear-Test-Ban Treaty, specifically citing the Lop Nur facility.

In February 2026, the US formally accused China of conducting a secret yield-producing nuclear test in June 2020 by using underground “decoupling” techniques to avoid seismic detection. Satellite intelligence has further identified infrastructure upgrades at at least seven Chinese sites. While China’s Mianyang laser complex is used for thermonuclear modeling, the parallel buildup of physical infrastructure supports an arsenal that has exceeded 600 warheads and is projected to reach 1,500 by 2035.

This situation has prompted domestic debate in the United States regarding the potential end of its nuclear test moratorium. President Donald Trump has indicated the US may resume nuclear testing on an “equal basis” if alleged breaches continue. Consequently, the US is seeking enhanced verification measures, including improved radiological and seismic detection capabilities.