Why did the Kosovo war start?

It started in 1998 and ended in 1999. It started over tentions between serbia and Kosovo. Yugoslavia broke up in the 80s into:

• Bosnia and Herzegovina - still under UN protectorate; population 3,981,000
• Croatia - population 4,491,000
• Kosovo - achieved independence in 2008; population 2,126,000
• Macedonia - still in dispute with Greece over its name; population 2,061,000
• Montengro - the smallest of former Yugoslavia countries; population 678,000
• Serbia - the largest of former Yugoslavia countries; population 7,395,000
• Slovenia - population 2,053,000

Since then ethnic differences have collided between all the counries. Serbia attacked Kosovo in 1998 when Kosovo only had 1 mil. people and wasn’t even accepted as a country by the whole world. N.A.T.O. came in in 1998 to help Kosovo and the war soon ended in 1999. The U.S. is one of the only countries that accept Kosovo as a country today.