But I do hold out a little bit of hope in the sense that seasteading can be attempted on nearly any state's doorstep. As US and Russian positions on the issue of independence of small states and regions in Western Eurasia shows, great powers are great friends of the principle of self-determination when it is limited to the spheres of interests of rival great powers. Perhaps if China feels its economic interest isn't sufficiently represented by its influence on US policy or vice versa?

There are naturally even more desperate alternatives including alliances with so called rogue states, some of which might in the near future posses nuclear weapons which for now seem to offer at least some minimal source of protection. Now naturally many might object to how one could contemplate to cooperate even for defence with a regime like say Iran, but I think this misses the point. The sovereignty of a chunk of land or sea or a virtual community, does allow things to go horribly wrong like say North Korea, but it also allows things to go potentially horribly right. Yes your cooperation may prolong the existence of X regime you dislike or even despise which has a few dozen million people living horribly, but at the same time it ensures billions of people living in a sort of ok or seemingly ok system have a working demonstration of a great or much better system, this might in itself greatly increase the probability of those states eventually transitioning to such systems.

Utilitarians (let alone others!) who think and have good reasons to think that their X form of government has this potential, need to shut up and calculate.