Kosovo was an autonomous province of serbia, itself a part of Yugoslavia, until NATO broke it up in 1999, as it was the last surviving socialist bloc in Europe after the fall of the USSR. NATO stirred up ethnic tensions, bombed the shit out of serbia, and carried out its strategy of balkanization, which Britain and the US had perfected in the middle east, asia, and latin america.

I highly suggest watching this parenti lecture on his book, to kill a nation, about the overthrow of Yugoslavia.