What is political disintegration?

This term is most commonly used to refer to the situation
in which a political entity that has been at least relatively united splits up into
smaller parts.  This is, for example, something that happened in many communist
countries after the fall of communism.  There are indications (see link below) that it
might happen in the European Union and even in the nation of
Belgium.

What happens in political disintegration is that
various parts of a political entity come to feel that their differences are too serious
to be overcome by whatever similarities they feel.  This often happens when a country is
made up of people from different ethnic groups.  In the case of the EU, it could happen
because that political entity is made up of a group of sovereign nations that have many
historical, ethnic, and cultural differences.