I imagine a big power like China would have to step in to enforce such international consensus, which would be massively unpopular; I’m sure by the time socialists have wrested control of this land from fascists et. al., we should be lucky if there is much capital, resources etc. still intact.

Agreed- though if you were to ask me, end of the day, there are only three main paths I can see ahead for the west- increasing fascism (with occasionally decreasing fascism portraying itself as a "return to liberalism") ie. the status quo which is inherently deeply unstable and headed off a cliff, internal collapse and revolution (which could then hopefully head to the right direction, and if not is probably headed eventually back to the cycles of fascism and "liberal democracy"), and world war (which would then- frankly, ideally see whatever's left afterwards needing to be decisively policed by an international consensus, and if you were to ask me- if it comes to that point, then it would also need to be de-whitened through either opening the floodgates of mass migration and foreign troops and administration to prevent such an imperial core from ever rising up again)