I could not agree with you more.
Certainly WWI was the defining event of the entire 20th century. It is interesting that the 20th century began with problems in the Balkans and ended in the Balkans.
It was Bismarck who said war in the Balkans was Not worth the healthy bones of a single Pomeranian grenadier.
Here’s another Bismarck quote. Back in 1888, he said “One day the great European War will come out of some damned foolish thing in the Balkans.”