In a post on X, DiNanno alleged China used ‘decoupling’ to hide its activities. “China has conducted nuclear explosive tests, including preparing for tests with designated yields in the hundreds of tonnes… China has used decoupling – a method to decrease the effectiveness of seismic monitoring – to hide its activities from the world. China conducted one such yield-producing nuclear test on June 22, 2020,” the US official wrote.
China has conducted nuclear explosive tests, including preparing for tests with designated yields in the hundreds of tons… China has used decoupling – a method to decrease the effectiveness of seismic monitoring – to hide its activities from the world. China conducted one such…
— Under Secretary of State Thomas G. DiNanno (@UnderSecT) February 6, 2026
In reference to the Strategic Arms Reduction Treaty, which aims to significantly cut down on deployed strategic nuclear warheads, he said, “New START was signed in 2010 and its limits on warheads and launchers are no longer relevant in 2026 when one nuclear power is expanding its arsenal at a scale and pace not seen in over half a century and another continues to maintain and develop a vast range of nuclear systems unconstrained by New START’s terms.”
“… almost all of the US deployed nuclear forces were subject to
New START, while only a fraction of Russia’s much larger stockpile was… exactly zero Chinese nuclear weapons were covered by New START,” the official added.He asserted that the United States can now finally take steps to strengthen deterrence, adding, “No longer constrained by the political-military circumstances of 2010 and the treaty they yielded and in response to the destabilising behaviour of these other countries.”
Last year, US President Donald Trump also hinted at similar accusations but without providing the same level of detail. In a social media post in October, he said that Washington would start testing nuclear weapons “on an equal basis” in response to testing programs by other countries.
DiNanno’s remarks came as he was presenting a new US strategy calling for three-way negotiations with Russia and China to negotiate new limits on nuclear weapons.
China has already declined to participate in disarmament negotiations with Moscow and Washington “at this stage”.
According to a report in Reuters, Shen Jian, China’s ambassador on disarmament, did not directly address DiNanno’s charge, but stated that Beijing has always dealt carefully and responsibly with nuclear problems. “China notes that the US continues in its statement to hype up the so-called China nuclear threat. China firmly opposes such false narratives,” he added.
