> I have no idea how to pull that off.

you start with a military force that is enough to prevent another sovereign nation from doing something bad like cutting off your comm link, or forcing or freezing your bank account...

A small and geographically distributed nuclear arsenal would also be a good starting point if you wanted to avoid having the large standing army needed for conventional deterrence.

Still doesn’t solve the banking issues, but one problem at a time I suppose.

Sure, but I have no idea how to pull that off. I have lots of other ideas that should work, but I don't know how to pull any of them off in practice.

Which means starting with a globally distributed computer that operates on the level above any military’s capacity to control a territory/populace…

Which is basically impossible. No old military platform in the ocean would be able to do that.

Indeed. A better idea might be to use custom in-house tech and avoid all public protocols and service providers. (Except TCP/IP. Maybe.)

The premise that you can buy secure comms from a commercial third party is... unconvincing.

There is a limit to that. North Korea does a lot of things that no government likes, but so far they are okay. There are a lot of bigger countries that have even more immunity to targeting.