[quote=Dinh AaronMk]
The formation of the full former Yugoslavia would probably also entail strong leaders, or complete ethnic subjugation to force them to settle down. The people of the Balkans don't exactly embrace each other very well.
[/quote]

I would go the route of complete ethnic subjugation as the Yugoslav Wars and the genocide of Bosinan Muslims is causes this to be more likely. Serbia and Greece still hold a good relationship with each other since they share the Eastern Orthodox Faith, share the same former Byzantine territories, and have a raging hatred of Turks among other things.