It's rare that it's achieved without bloodshed: consider the partition of India for the worst example, or the war in Kosovo, or the wars between Ethiopia and Er

It's rare that it's achieved without bloodshed: consider the partition of India for the worst example, or the war in Kosovo, or the wars between Ethiopia and Eritrea. It's true that the breakup of Czechoslovakia into two countries was peaceful and smooth, but that's an exception. The problem is that how to divide or even whether to divide is a complex and controversial question and people tend to fight about it. I think your guess is backwards: attempting to split up countries makes war more likely if you look at the record, at least, a local war.