"The Balkan peninsula is, according to some definitions, what lies south of the rivers Sava and Danube from the city of Belgrade."
"Slovenia, too, was once part of Yugoslavia. It is their recent independence that has allowed for the Slovenes to re-proclaim their desire to be considered Central European".
Is Slovakia part of the Balkans- No link
Slovakia was a part of Czechoslovakia and gained indendence in 1993 when splitting from Czech Republic after democratic elections
Kosovo is still part of Serbia.
Through my life, I am chagrined to admit I often confused Baltic States and Balkan states, despite knowing WWI began with the assassination in Sarajevo and had a close childhood friend who was born in Estonia.