They sided with fascist forces in the Western provinces of the old Austro-Hungarian Empire.
Catholics,Orthodox and Muslims.
Natural allies of any Western country would be the Catholics.
Of course current Foreign policy does some incredibly stupid things.
Yes, and with Germany's WWII fascist Balkan allies -- but for the life of us, we couldn't figure out why the US would chose to side with those Balkan ethnic groups who had been US enemies, against those who had been American allies. But, according to this, the US didn't do the choosing -- Germany did -- which makes some sense of this lunacy.