US Claims Secret Chinese Nuclear Tests at Lop Nur Signal Global Shift

US reveals evidence of secret Chinese nuclear tests at Lop Nur, marking a shift in global security as the New START treaty expires and tripartite tensions rise.

By: AXL Media

Published: Feb 24, 2026, 7:44 AM EST

Source: Information for this report was sourced from The Diplomat

The Revelation of Clandestine Explosions in Xinjiang

The United States government has officially accused Beijing of conducting secret nuclear explosive tests, a move that fundamentally challenges the long-standing international moratorium on nuclear detonations. According to statements made by Under Secretary of State Thomas DiNanno at the Conference on Disarmament in Geneva, US intelligence identified at least one "yield-producing" test conducted on June 22, 2020. This event, which registered as a 2.75 magnitude seismic signal, originated from the Lop Nur test site in China’s western Xinjiang region.

US officials allege that the People’s Liberation Army (PLA) utilized "decoupling" techniques—detonating devices within large underground cavities to muffle seismic waves—to hide the true scale of the explosions. While the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) noted that its current systems did not detect an event definitively consistent with a nuclear explosion, Washington maintains that China’s efforts were specifically designed to bypass international monitoring. These revelations suggest that the 2020 event was not an isolated incident, but part of a broader program to refine a new generation of tactical nuclear warheads.

Strategic Context and the Collapse of Restraint

These disclosures arrive at a critical juncture for global security. On February 5, 2026, the New START treaty between the United States and Russia officially expired, leaving the world without a legal framework to limit the deployment of the planet's most destructive weapons for the first time in decades. The lapse of this treaty removes the "guardrails" that governed the bilateral relationship between Washington and Moscow during and after the Cold War.

By highlighting Chinese violations now, the US is signaling that the old bilateral model of arms control is no longer sufficient. The strategic landscape has shifted from a two-way standoff to a complex three-way rivalry. Analysts suggest that the timing of these revelations is a deliberate attempt by the Trump administration to justify a potential US return to nuclear testing "on an equal basis" and to pressure Beijing into entering multilateral negotiations—something China has historically resisted.