First of all in this thread we will consider the balkan geographical region to extend from modern day Slovenia till Greece till northern Serbia and Wallachia-Moldavia.
Nowadays Balkans are known for being one of the most divided ethnically regions of the world.
Today it consists of 4 main ethnicities . 1)Southern slavs* (Serbia, Macedonia, Bulgaria, Bosnia Hg, Croatia)
*The Southern slavs are distinguished between the East and the West divisions. East division consists of Serbs, Bulgars, Montenegrins and Macedonians. While the west consists of Slovenian, Bosnian and Croatian people (who are mostly influenced religionmusly and polticaly by the Italian and Austrian type of governments and cultures, because they once used to be part of the Habsurg empire )
This split between the southern slavs goes further deep as the east is orthodox and the west is Catholic (with some Muslim minorities).
Historically the Western division is more influenced by the Western world than the east division. Since the latter used to be under the ottoman rule for 400+ years, while the west was ruled by the Austrian empire. Thus it was exposed to renaissance and enlightenment, while the east was culturally and technologically stationary and influenced by middle Eastern culture and religion.
In order to discuss realistically how much is this union possible . First we need to know how many and who of the balkan peoples could join this union or not, in order for this union to be relatively stable and not get dismantled in the first decade of its existence.
For example we have seen in the past that the Habsurg Empire and the Jugoslavian Republic both collapsed because of the instability all these ethnicities they ruled yielded because of their strong nationalist spirit.
The lesson we took from these two empires is Croats, Bosnians and Serbs cannot be in the same empire, Union, federation etc. Because they simply cannot coexist and their bitter rivalry will bring instability to whoever rules them.
Thus our union should contain only one of these peoples, otherwise it will consumes most of its resources on this rivalry .
Thus it should contain , Either Eastern South slav division either Western South slav division. In my opinion it should be the Eastern division , because the Western is not connected to the rest of the balkans in no way whatsoever (either that's economy, either culture, either language or even culture) .
Moving on towards the south we find the Albanians. Well Albanians are a weird situation when it comes to their nationalism honestly. They were the last of the balkan people to get an ethnic consciousness and the last to get independence. Although they have a very bitter rivalry on their northern border with the Serbs, the situation on the southern border isn't the same as it once used to be nowadays. Since the 90s more than one million Albanians have migrated to Greece. Thus the Albanian nationalism may still be "burning", but the economic and politic ties between Greece and Albania are so strong nowadays that there is no real rivalry whatsoever, of course except a few bunch of ultra nationalist Albanian groups. Thus the addition of Albania into the union would be tricky because of the Serbs, but their economic and political dependance to Greece is stronger than their Serbian rivalry.
Next on the line are the Greeks. These people have managed to diplomatically tighten relationships with Bulgarian, Albanian, Macedonian and Serbian governments over the past decades. Economically, Greece is the leader the southern balkan region in many ways and the only ones who could convince all the others to persuit this union . That means that a beginner 3 part base for this union could be Greece, Serbia and Bulgaria. Since those three are the strongest of all other balkan countries in military terms. Their combined economies are probably one of the largest in Eastern Europe. Religiously and ethnically speaking they already are very united nowadays and their combined interests are pretty similar to each other.
A further addition to the union could be Macedonia. Macedonia heavily depends , economically and militarily on Greece. Even the national Bank of Macedonia is just a branch of Greek Bank (btw same is true for the albanian banks) . Thus her entry into the union would be very possible and regarded by all the other 2 main members.
About the governing body of the union. At first I was thinking that this union could be created only by a Greek initiative, since the Greeks are the only balkans who have the economical, military and political resources can actually make this union possible. Thus a Greek head of state with some Greek, serb and Bulgarian ministers was my first idea.
But I thought that in order for this union to stabilise fast, it needs one more centralised goverment at first. Thus a constitutional monarchy run by a temporary Greek governor for the union , elected by the people of the Union, would be a more efficient one.
Please tell me your opinions and ideas. And especially if you have noticed flaws, tell me all the flaws.
Thank you for your time,