US Accuses China of Covert Nuclear Test Post-Galwan Clash Amidst Arms Treaty Expiry

The United States has accused China of conducting a covert nuclear explosive test on June 22, 2020, merely a week after the violent Galwan Valley clash between Indian and Chinese troops. This significant accusation, initially made by the Trump administration, has resurfaced and gained renewed attention in early February 2026, coinciding with the formal expiry of the New START treaty, the last remaining nuclear arms control agreement between the US and Russia. The core of the US allegation, articulated by then-Under Secretary of State for Arms Control and International Security Thomas G. DiNanno, was that China engaged in 'yield-producing' nuclear tests, using sophisticated 'decoupling' techniques to evade detection by international monitoring systems. Decoupling involves detonating nuclear devices in large underground cavities, which significantly muffles seismic signals, making them harder to detect through the global network of seismic monitoring stations. The timing of the alleged test, June 22, 2020, is particularly salient for India, as it followed closely after the deadly Galwan Valley confrontation on June 15, 2020. The Galwan clash resulted in the deaths of 20 Indian soldiers and an undisclosed number of Chinese casualties, marking the most serious military confrontation between the two nuclear-armed neighbours in decades. The proximity of these two events—a border clash and an alleged covert nuclear test—raised concerns about China's assertive military posture and its implications for regional stability. However, the US claims have been met with staunch denials from Beijing. Chinese officials, including the foreign ministry spokesperson Lin Jian, dismissed the accusations as 'false narratives' and maintained that China has always acted prudently and responsibly on nuclear issues. Furthermore, the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), which operates a global network of monitoring stations designed to detect nuclear explosions, stated that its system did not detect any event consistent with the characteristics of a nuclear weapon test explosion on the alleged date (June 22, 2020), and subsequent detailed analyses have not altered this determination. This lack of independent corroboration from the CTBTO adds a layer of complexity and skepticism to the US allegations. The broader context for the re-emergence of these accusations in early 2026 is the expiration of the New START treaty on February 5, 2026. This treaty, signed in 2010 by the US and Russia, imposed verifiable limits on the deployed strategic nuclear arsenals of both nations. With its expiration, the world's two largest nuclear powers are now without binding limits on their strategic arsenals for the first time in over five decades, leading to renewed calls from Washington for a broader nuclear weapons agreement that includes China. The Trump administration had long advocated for China's inclusion in arms control talks, arguing that Beijing's expanding nuclear arsenal, which is not constrained by such treaties, poses a growing threat. While the US State Department has consistently raised concerns about China's activities at its Lop Nur Nuclear Test Site in its annual compliance reports, the specific accusation of a 'yield-producing' test on June 22, 2020, and the method of 'decoupling,' represents a heightened level of detail in the allegations. The timing of the renewed discussion of these claims, alongside the New START treaty's expiry, underscores ongoing geopolitical tensions and the precarious state of global nuclear arms control, with significant implications for international security and particularly for India, given its shared border and historical military confrontations with China. The Indian audience views this news with high importance due to its direct relevance to national security and regional dynamics.

Frequently Asked Questions

Read Full Story on Quick Digest