I think a bigger problem for the European powers was the unconcious self-glorification created by their colonial conquests.
Tiny European armies repeatedly defeated much larger native armies, even when similarly armed. The Maxim gun and other high tech weaponry just made it worse.
So the Brits, and the French, and the Germans looked at their ability to crush native armies when outnumbered 20:1 in India, North Africa and East Africa and thought it was due entirely to their own national prowess. Then extrapolated that inappropriately to similar results when facing other Euro armies.
The American Civil War and the Boer War should have given them reason to think otherwise, but neither the American nor the Boers were “real armies” in the Euro POV, so they didn’t count.
So their conflicting delusions banged into each other and blew up the world. All sides had their plans to win the war, and apparently never gave much thought to the fact that the enemy gets a vote, you can’t just march out and implement your plan.
I don’t disagree with your assertion, but the Europeans had experienced all the wars I listed AFTER both the Civil War and the Boer Wars, and none led to catastrophe. Okay, the second Boer War I did not list, but it was the guerrilla war aspects that were particularly nasty, not the conventional fighting of army against army.
I can’t see how one avoids the conclusion that Europe was still looking at war as it had in 1864, without realizing that the nature of war had changed by 1914. Everyone understood what total war meant in 1945, because they had been through two before and had seen atomic bombs in action. No one could imagine WWI in 1914.
I think we’ll both agree there was massive failure of imagination in the decision making when going forward to war in 1914. The Germans in particular were expecting to fight and win a quick, decisive conflict as they had in 1870. I can’t believe that any of the European leadership, as inbred and decadent as it was, would have jumped for mobilization if they had any clue it was going to mean millions of dead four years later.