Just my humble opinion:
Albanian uprisings in southern Serbia, eastern Montenegro and western Macedonia (in order to create Greater Albania). They are supported by Kosovo and Albania.
1) Kosovo declares independence
2) S&M dow kosovo (partly because it declared independence, partly because they are supporting the uprisings)
3) Albania dow S&M in response
4) Macedonia organizes a brutal crackdown on Albanians in Macedonia, causing both Kosovo and Albania to dow Macedonia
5) S&M form an alliance with Macedonia to jointly crush Albania and Kosovo
6) Serbs in Bosnia, see a chance for a creation of a greater Serbia, and create an uprising in Bosnia
7) Now Bosnia makes a brutal crackdown on the serbs, causing S&M dow Bosnia.
8) Croatia, feeling itself threatened by a possible greater Serbia, forms an alliance with Bosnia, Albania and Kosovo against S&M and Macedonia.
This is just a very rough draft, which I think could be plausible and would be very interesting.
P.S: SNS, I didn't know there were any of us in Cetinje.