Sans said:
If WW1 was indeed inevitable, then what would've kickstarted it had the assasination of the archduke never happened/didn't succeed? I understand that the German General Staff wanted to have a war with Russia before their railway infrastructure caught up with Germany and would be too overwhelming an enemy to take down, so perhaps it would go down that route?
2 important things to remember about WWI kicking off;
1) they didn't think about war the same way we do. WWI was really the war that got people around the world to consider war bad. A good illustration of this is the story that, when WWI was declared in London, there was celebrating and dancing in the streets, while when WWII was declared people were weeping. I'm not sure how accurate the story is, but it does a good job illustrating the difference in sentiment between the wars. WWI was so horrible it changed people's idea of war. Look how hard the English tried to stay out of WWII, Neville Chamberlain's famous "peace in our time" speech and all.
2) the buildup of alliances, military technology, and nationalist sentiment was so high in Europe everyone was itching to go at it to a) knock the other alliance down a few pegs, b) play with and prove that they had the best "toys", and c) prove that their people/culture were superior to all others.
Everyone thought the war would be over in a matter of months, that with the strength of the forces arrayed against each other, neither side would be able to last long. There was almost no one considering the possibility of what was to come.
All that being said, I'm still not sure WWI, as it was, was inevitable, but some form of war definitely was. As for what would have set it off, my guess would be the Germans attacking France across Belgium, as that plan was in place since the end of the Franco-Prussian wars where Germany had defeated France. Thinking at the time held that a defeated enemy is likely to declare war on their old adversary (France on Germany), and the army that strikes first usually wins, so the German standing plan, well before the buildup of WWI, was to push across Belgium into France in a quick march that would knock France out before a real war started, so I think Germany would have gone for broke. Of course, if they had waited they may have been able o fight that war without all the alliances coming into play, meaning it wouldn't have been WWI, but that's just speculation.