They don't have to coordinate.
Nations can have their own self-serving regulations and laws that choke out Bitcoin mining making it a great burden to do (economically and legally). They could also force all miners in their jurisdiction to censor certain transactions. As fee pressure rises on censored transactions you *might* be able to get other miners in a different country to mine it, but it's going to cost you a lot of money and confirmation time so it won't be an everyday thing that most people do.
If Bitcoin was private and anonymous you couldn't pick out and censor individual transactions because they all would look the same. Anyone attacking the network would be forced to indefinitely censor the *entire* network to stop a few transactions, which is much costlier and harder to do all things equal.
CPU mining is relatively easier to attack, but easier to spin up more CPUs to push back against an attack once it is in progress
ASIC mining is relatively harder to attack, but harder to spin up more ASICs to push back against an attack once it is in progress