i think most of us already know that you cannot blindly apply soviet or chinese socialism to our respective states without considering the underlying reasons for reform and opening up and the rapid industrialisation of the soviet union. you can’t just create a sez in fucking malmo and expect to become a socialist paradise in a month, this is obvious. once a socialist state or multiple pop up in europe or north america, in the near future, the first thing that would happen is, most likely, a complete blockade. the remaining capitalist states in europe or nato if thats still around would either invade you or sink any ships sailing into your ports. any semblance of socialism in the west, especially in the core, would be seen as an existential threat (correctly so, actually). and you dont have any manufacturing capacity at home and definenetly not enough to resist the combined military effort of the west. like, what the fuck do you do once you, as a deindustrialized state with an aging population, have your trade cut off and have to fight a war without any nearby allies? maybe the billions of climate refugees can aid any reindustrialization effort if thats on the table, but thats really not gonna be on the table as intervention would happens as soon as you take control, you just dont have the time. this is ignoring any russian or chinese interference or an unforseeable change in the global economic system within 10 or 20 years, of course. that could change a lot and would be desirable. but i cant and we cant predict exactly how that would change the equation here, so i dont know how i could consider that in the scenario.
The bigger question is where this socialist state comes from, how it manages to come into being. Surely you don’t expect people to simply vote to secede and form the socialist state.
A much more likely scenario would be the weakening of the pre-existing state domestically, to the point where there is room for organized actors to replace some of the state functions. This would need to happen with some economic backing: firms of substantial size that can provide the money to make social services happen. Most likely there’s a party apparatus that facilitates these things, not an openly insurgent party but a special-interests party.
At a certain point, the party or regional assembly declares that they will function as an autonomous subunit, leaving to the national government only the questions of national defense and international trade arrangements. Leave the country nominally intact, while creating your own local laws. Then, with the economic engines you have, do the Deng gambit: make sure the imperial core economies rely on you enough that to go to war with you would be self-destructive.
Maybe at some point a switch flips, and the region goes from devolution to independence. By that time (and really, throughout every part of this) you want lots of weapons.