Belgium is a country not unlike the former Czechoslovakia, made up of two quite different cultures. See this article in the Weekly Standard concerning the issues there and the future of Flemish/Walloon Belgium.
The future of Belgium gives us some indication of what to expect from other multicultural nations like Canada, and perhaps someday the United States. Meanwhile, Andhra Pradesh, an Indian state, will soon be splitting in two as a result of this same kind of cultural tension.