> only reasonable reaction is a Metternichian rebalancing of powers

It's rational, but it comes at costs. (And with costs.) China would have to put a stop to Putin's revanchism. Otherwise, Europe is just financing its burial and subjugation. And the EU would have to sign off on China's human-right records, and, in all likelihood, Taiwan policy. That, in turn, sets up a clash with the rest of Asia.

That is pretty much my opinion as well.