Agreed on CCP seeming non-rational. As best I can figure it's that they've not only promoted 'zero covid' as a good solution (to be fair, pre-Omicron, it was) but as part of that promotion amplified some of the anti-vaxxer attacks on the Western vaccines - and they don't have one that works on Omicron. They know they'll have uptake issues if they import a Western vaccine. I see the lockdowns as doubling down on zero covid after they've painted themselves into a corner.

Also, have you read any of Peter Zeihan's work on geopolitics (or watched snippets of his presentations on youtube)? The northern Chinese may have realized just how very screwed they are. If they have, then there's the whole 'existential threat' thing mixed in...