U.S. officials have not conducted an explosive nuclear test since the 1992 moratorium, despite President Trump’s October 2025 directive to resume on a parity basis with alleged low-yield Chinese and Russian activities. Recent developments center on verification rather than detonation: the National Nuclear Security Administration’s September 30, 2026, non-nuclear chemical high-explosive experiment at the Nevada National Security Site aimed to refine detection of decoupled blasts, while bilateral talks with China explore reciprocal site visits and confidence-building measures under P5 channels. Congressional requirements for approval, bipartisan stockpile stewardship certifications, and the absence of site preparations keep implied probabilities low across 2026 deadlines. Any shift would require confirmed test preparations or a breakdown in ongoing diplomatic verification efforts within the resolution window.