It’s been my take for a long time that China was much more involved than we were led to believe.
There’s your source.
Thank you for your observations, estimations. I appreciate your insight.
China seems a natural supporter.
Fusion technology is readily available from the Russians, whom I suspect.
What is odd is that China has a seismic post and an air sniffer for isotopes very close to the blast site. That post has greatly contributed to the monitoring data for all the NK nuke tests.
China, also has contributed little to their fission program.