U.S. Says China Tested Nuke Week After Galwan Clash

U.S. Under Secretary for Arms Control and International Security, Thomas G. DiNanno said on Friday, China has conducted a nuclear test on June 22, 2020 | Illustrative Image: StratPost

A week after the People’s Liberation Army clashed with the Indian Army at Galwan in India’s northern frontier region of Leh, the People’s Republic of China conducted a nuclear test, according to the U.S. State Department.

The U.S. Under Secretary for Arms Control and International Security, Thomas G. DiNanno, told the Conference on Disarmament  in Geneva on Friday, “Today, I can reveal that the U.S. Government is aware that China has conducted nuclear explosive tests, including preparing for tests with designated yields in the hundreds of tons. The PLA sought to conceal testing by obfuscating the nuclear explosions because it recognised these tests violate test ban commitments. China has used decoupling – a method to decrease the effectiveness of seismic monitoring – to hide their activities from the world. China conducted one such yield producing nuclear test on June 22 of 2020.”

Tensions began simmering between the Indian Army and the PLA in the spring of 2020, with a number of standoffs beginning May 05, 2020 at several locations along the frontier between the two countries. Heavy clashes took place at Galwan took place on June 15, 2020, resulting in the deaths of 20 Indian soldiers with estimated Chinese casualties of around 40 personnel.

The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) said on Friday it did not detect the test.

A statement by the executive secretary of the Comprehensive Test Ban Treaty Organisation (CTBTO), Robert Floyd said, “The CTBTO’s International Monitoring System (IMS) is capable of detecting nuclear test explosions with a yield equivalent to or greater than approximately 500 tonnes of TNT, including detecting all six tests conducted and declared by the DPRK. Below 500 tonnes is roughly 3 percent of the yield of the explosion that devastated Hiroshima.” 

Floyd said in his statement, “Regarding reports of possible nuclear tests with yields in the hundreds of tonnes, on 22 June 2020, the CTBTO’s IMS did not detect any event consistent with the characteristics of a nuclear weapon test explosion at that time. Subsequent, more detailed analyses have not altered that determination.”

On April 15, 2020, the U.S. State Department had said in a report that China may have conducted low-yield tests.

According to a 1993 report by H. Doublas Garbin at the U.S. Sandia National Laboratories, ‘One proven method of evading the detection of a nuclear test is to decouple the explosion with a large air-filled cavity. Past tests have show it is possible to substantially reduce the seismic energy emanating from a nuclear explosion by as much as two orders of magnitude. The problem is not whether it can be done; the problem is the expense involved in mining a large cavity to fully decouple any reasonable size test.’

DiNanno’s statement to the Conference on Disarmament part of a speech explaining the reason for the decision by the U.S. government to allow the New START nuclear weapons treaty with Russia to expire on Thursday. New START was a nuclear arms control treaty between the U.S. and Russia signed in 2010 limiting each side to 1,550 strategic nuclear warheads and capping deployed intercontinental, submarine-launched and heavy bomber delivery systems. New START, which expired on February 05, 2026, included on-site inspections, data exchanges and notification measures designed to provide transparency and reduce the risk of miscalculation between the two countries.

U.S. Secretary of State Marco Rubio said in a statement on Friday, “China’s rapid and opaque expansion of its nuclear arsenal since New START entered into force has rendered past models of arms control, based upon bilateral agreements between the United States and Russia, obsolete. Since 2020, China has increased its nuclear weapons stockpile from the low 200s to more than 600 and is on pace to have more than 1,000 warheads by 2030. An arms control arrangement that does not account for China’s build-up, which Russia is supporting, will undoubtedly leave the United States and our allies less safe.”

The Bulletin of the Atomic Scientists estimated last year that China ‘possesses 600 nuclear warheads,’ ‘believed to have the fastest-growing nuclear arsenal among the nine nuclear-armed states,’ and ‘was the only Party to the Treaty if Non-Proliferation of Nuclear Weapons that is significantly increasing its nuclear arsenal.’

India and China have achieved disengagement at some friction points on the frontier after multiple rounds and levels of talks between the two countries but both maintain large deployment of forces without de-escalation.