Well, yes. That is true. He also knew that the Balkans have ALWAYS been a source of trouble, for 700 years.....
Remember, that WW I started when a Serbian Nationalist murdered the Austrian heir to the throne, Archduke Francis Ferdinand........
That's one perspective.
Some would say that it began when Germany declared on Russia, turning a local conflict into WWI.
Others would say the wheels were set in motion when AH annexed Slavic Bosnia or when they first occupied the territory.
When did the "War of Northern Aggression" or "US Civil War" begin? Did not the Confederate States rise up against a power from the north?