Did China conduct secret nuclear test days after Galwan clash with India?

The US has just dropped a bombshell, sharing publicly for the first time that China conducted a secret nuclear test in 2020, just days after deadly clashes with India in the Galwan Valley along the border, and as the world was grappling with Covid-19. The allegation was made by US Under Secretary of State Thomas DiNanno during a United Nations conference on disarmament in Geneva on Friday. Crucially, the allegation comes as the last nuclear arms deal between the US and Russia ended on February 5, with President Trump keen on roping in China for any future nuke pact.

In a series of posts on X, DiNanno said the US had intel of China conducting covert nuclear tests to dodge detection by global agencies. The senior US official claimed China conducted one such nuclear test on June 22, 2020. This is just seven days after Indian and Chinese forces clashed in Galwan amid the border standoff in eastern Ladakh -- the deadliest confrontation between New Delhi and Beijing in decades.

India lost 20 soldiers in the hand-to-hand combat (an agreement between the two countries forbids the use of firearms). China, which never officially revealed the death toll, lost more troops than India, according to global reports. The standoff ended only in 2024 after both sides reached a deal.

WHAT US SAID ON CHINA NUCLEAR TEST?

Now, it has come to light that China allegedly conducted the nuclear test just seven days later, possibly at the Lop Nur site in the Xinjiang region, bordering India. The US official said China used a technique called "decoupling" that made it harder to detect seismic signals.

You must be wondering what is decoupling? In simple terms, it basically is a technique where an explosive is detonated in a large underground cavity to muffle seismic waves. It is a classic way to potentially hide such tests.

"The US government is aware that China has conducted nuclear explosive tests, including preparing for tests with designated yields in the hundreds of tons. China has used decoupling to hide its activities from the world. China conducted one such yield-producing nuclear test on June 22, 2020," the US official tweeted.

The development comes at a time when the India-China border standoff has reverberated in Parliament Budget session, with Leader of the Opposition Rahul Gandhi accusing the Modi government of mishandling the issue.

WHY TIMING IS SIGNIFICANT?

Now, while the US did not explicitly link the nuclear test to the border conflict with India, the timing of it is significant. At that time, the border conflict was at its peak, with aggressive troop movements along the Line of Actual Control or LAC. Tensions arose over regional stability as both nuclear-armed countries came head-to-head.

However, a section of geopolitical experts has floated another theory. If China did conduct such a nuclear test, it would have taken months of meticulous planning. In such a scenario, the Galwan clash, which drew global attention and made headlines, provided a perfect mask for China to conduct a nuclear test without any distraction.

It had to do it covertly as China is a signatory to the Comprehensive Nuclear Test Ban Treaty (CTBT), which bans explosive nuclear tests. However, China, like the US, has not ratified the treaty.

WHY IS US WARY OF CHINA?

The US has been wary of China ramping up its nuclear arsenal. Beijing is believed to have around 600 nuclear warheads. Last year, in November, Trump ordered the military to resume testing of nuclear weapons as China and Pakistan were doing so. "Russia's testing and China's testing, but they don't talk about it," he said in an interview.

This is why Trump now wants China to be part of any future nuclear deal with Russia. The Strategic Arms Reduction Treaty or START, which helped end the Cold War, placed limits on the nuclear arsenals of the US and Russia. Its expiry has raised concerns of a global arms race.

China's ambassador on nuclear disarmament, Shen Jian, however, has not denied or rejected DiNanno's charge of conducting a test in 2020. Jian said Beijing had always acted responsibly on nuclear issues, Reuters reported.

"China notes that the US continues in its statement to hype up the so-called China nuclear threat. China firmly opposes such false narratives... The US is the culprit for the aggravation of the arms race," Jian said.

Separately, an international monitor, the Comprehensive Nuclear-Test-Ban Treaty Organisation, said its system did not detect any nuclear activities in China during that period.