Wars in Europe may or may not have been inevitable, but that doesn't mean any of them HAVE to turn into a general European war and later a World War.
Yep +1
Similarly the AH empire wasn't doomed to collapse, although it was facing mounting internal pressures that would need to be tackled without resorting to more of the same, and officially adding Bosnia to the fold in 1908 was always going to have consequences both for them internally and internationally in Eastern Europe.
The problem was the alliance system was designed to prevent general war between two or more great powers. But not necessarily smaller wars between one great power and lesser ones. And it had worked pretty well at that for 45ish years.
Thing is while no one was truly dumb, or relentlessly belligerent there were some really dumb moves and stupidly belligerent moves in July/Aug1914 that kind of boxed everyone else into a corner making the alliance system a trap not a precaution.
what compounds this was there were a couple of factions who felt they needed to put their head down and charge or lose their opportunity. namely:
1). the AH who didn't want to go to intentional mediation over FF and Serbia (or at least if it had to they wanted to do so with the AH Flag firmly planted on Serbian soil nad the world a fait accompli).
2). Germany gives AH a Blank cheque, (and some in Germany seizing what they thought was their political opportune chance for war)
and the thing is the alliance system gets the blame , but IMO the two big reasons why we get a general European and then World war are actually because the alliance system was ignored in favour of short term policy in two main ways.
1). AH for some reason thought the Russians wouldn't honour their treaty with Serbia if they just went in quick enough to catch the Russians on the hop* (although because AH was pretty fractious at this point they're not quick** meaning every was watching and sympathy for AH had dissipated).
2). Germany thought that either Belgium would let*** German troops through or that Britain wouldn't honour**** it treaty with Belgium
The irony is both moves involved assuming other great powers would ignore their treaties, while both AH & Germany were invoking and meeting their own treaty obligations!
And the thing is I've never come across of good reason for why either of these two made those decisions beyond the necessity of those choices being driven by the course they had already taken. In that AH can't back down once it's thumped it chest so hard with demands, and Germany's Schlieffen 'Plan'.
*only they mobilised faster than they had in the 1st half of the C19th because despite European sneering Russia has modernised somewhat
**Including not telling the army command until the last minute oh you'll need to mobilise
***neutrality having a different meaning in turn od the century German.
****Not wanting to get into land wars in Europe not being the same as being unwilling if it comes to it