I was on the CIA world factbook and it said that interethnic warfare was a problem...what does that mean?

It means war and battles between different ethnic groups.

oh so like in America during the civil war?

Not really.

Interethnic warfare is difficult for most of us Americans to understand.

In the Balkans, most people live in the same area as their ancestors have for hundreds of years. They follow the same religion and marry people within the same ethnic group. They are clannish and are prejudiced against other ethnic groups. They have long memories and remember slights and battles that happened hundreds of years before. When the former Yugoslavia broke up, Serbs in Kosovo claimed that land because of a battle there some 800 years ago.

oh i can see that it's really confusing... But i thought when Yugoslavia broke they broke because of the government.

Yugoslavia broke up because the various ethnic groups wanted to be independent. They had stayed together only because a strong dictator ruled this country.

The same thing is going on in Sudan correct...Is that interethnic warfare?

Yes! You're right!

Did Czechoslovakia break for the same reason?

Ethnic strife was only a small part of the breakup of Czechoslovakia. Their reasons were historic, economic, and political.

http://en.wikipedia.org/wiki/Dissolution_of_Czechoslovakia#Background

Wow, I never realized how many different reasons there are for a country to break...Or that so many countries have broken!!!