Let’s just assume for the sake of argument that Kiev falls and the political leadership of Ukraine is taken into custody. What is the next move politically? Show trials? No trials? A bullet in the brain pan in some basement cell in Lubyanka?
What is the next move militarily to secure the country? Does Russia move forces right up to the NATO frontier? That might get dicey. If they don’t then they would seem to be conceding a swath of land to a rump-Ukrainian government and a secure basing area for a guerrilla force to rest, train & refit.
This all interlocks. If Russia makes half-measures militarily (as the US would) and treats the legitimate Ukrainian government harshly then there will be a guerrilla war that could last a long time — maybe until the next general European war breaks out.
Good questions and thoughts.
Seems you’ve covered the options up to the point of Russia just keeping on going.