Purely asking this for some fiction writing
Balkanised has become slang for “region formerly in a federation or union that has split into many small independent nations after the fall of said Union. Like happened in the Balkan region with the fall of USSR”
500 years of general public and economic decline where access to information is greatly reduced and local governments slowly replace the influence of the national government. Over time they organize locally for protection as outsiders begin to pillage whatever value remains. It’ll look a lot like what happened to the Roman Empire.