Siberia?

[Axtremus]

https://thehill.com/opinion/international/5379824-china-wants-to-invade-siberia-not-taiwan/

The article, citing a NYT report, argues that China may invade Siberia before it invades Taiwan; reasons being:

• War with Taiwan will be very costly to all sides
• Siberia has lots of natural resources that China needs
• Russian defense are weakened and distracted by the war with Ukraine

Thus, the argument goes that while Taiwan "unification" remains a useful rhetoric, Siberia makes a lower cost, higher return target for China if it were to invade somebody.

[Mik]

I know China claims some parts of eastern Siberia. It’s possible, but the risks of it going nuke are probably too great.

[Renauda]

The scenario has been around for some time. It is plausible - particularly if Moscow chooses to become more like North Korea as opposed to the current ersatz Imperial Russia - although why would China take that route when it can ensure Russia remains very much its junior partner through economic means?

Agree with Mik though, if such a scenario were to play out, the nuclear threshold would be crossed very quickly.