> You can imagine outlawing processing some crypto transactions in some area. Miners have no choice but to comply, leading to at least a fork and massive confusion, at most to actual enforcement of the rule.

It is not a geo-location issue. The enforcement measures in question either manage to control 50% of the hashrate or they don't. If they don't, the protocol will ignore their censorship. Yes, they could continue mining a minority fork chain, but you would need to convince Bitcoin-users and services to use the fork instead of the uncensored version. You could imagine this being done by force: ISPs block the download of the software, exchanges no longer trade it etc.

The point is merely: <50%, the power is not with the miners at all; it is the users that need to be controlled.