On the other hand: Out of the 100 wars that happen in the 1910's in parallel universes only 1 will lead to the follow up. We can see this because of how people reacted to Ferdinand dying: People could have worked something out, but there were a lot of tensions, a bunch of countries thought they had much more to gain than they had to lose in a large scale conflict, so a war was coming for sure.
Europe was a powder keg during that time and just needed a spark to explode.
