Revelations of Chinese nuclear tests mark start of a new nuclear arms race era

How serious is this negative prospect?

Is it true that China was never before party to any nuclear weapons agreements?

"... And as we sit here today, China’s entire nuclear arsenal has no limits, no transparency, no declarations, and no controls. ..."

"As major powers renew their focus on nuclear testing, the world may be entering a new nuclear era.

Revelations that Beijing has conducted secret nuclear tests should trigger greater focus on China’s expanding nuclear arsenal. China’s nuclear expansion and modernisation could lead to an accelerated and unbridled nuclear arms race, particularly since Chinese President Xi Jinping refuses to participate in meaningful dialogue and abide by agreements on such issues. This would have implications that go beyond the US-China competition: it would affect global stability; undermine international non-proliferation norms and efforts; and harm the prospects of future arms control agreements.

On 6 February, US Under Secretary of State for Arms Control and International Security Thomas DiNanno revealed that the US was aware that China had been conducting nuclear tests. One such test was conducted in June 2020, based on US assessments. ..."

Revelations of Chinese nuclear tests mark start of a new era | The Strategist

Statement to the Conference on Disarmament (original US government statement)