Mount Holyoke College
Mount Holyoke College: The Balkans' Lethal Nationalism
This article by historian William Hagan, "The Balkans' Lethal Nationalisms," (Foreign Affairs 78, no. 4 (July 1999), traces the background for the then contemporary conditions in Kosovo.
Other
War at the Crossroads: The Emergence of Nationalism
This site contains information about nationalism in the Balkans from the early 1900's to the present.