Sometimes it does, where there is national conflict in a multinational state, especially when one nation opresses other, separating them into states (even small ones) will make things better. Example: Ireland and UK or post war resettlement at the Poland borders.

But libs, they are only regurgitating State Department divide et impera policy to break up countries that are resisting USA. Russia or China broken to dozen(s) of pieces would have no chance to defend itself even if communists taken power in half of them because other half would have compradors installed.