To understand pacificism in Western Europe, on the first day of the Battle of the Somme in 1916 Britain had nearly 60,000 casualties (of whom 20,000 were killed). In one day.
The troops didn’t know it at the time, but the French were about to lose Verdun (which may have taken them out of the war if breached); they relayed this to the British, who sent their troops over the top to draw German troops away from Verdun. By the end of the day, the British weren’t even running towards the German trenches any more; they simply walked towards them and were mowed down by machine guns.
25 years later they were asked to do it again, and much of Europe said “no thanks”; they realized all those men lost in the “war to end all wars” had died for nothing. It has given them a healthy skepticism that holds their governments much more accountable to their populations than we have here.
WWI was a disaster on all fronts.. an entire continent at war due to treaty agreements that got triggered over an individuals assassination, followed by years of stalemate meat grinding.
I cannot even begin to comprehend what madness had to be going on in leaders minds after it was clearly obvious what a disaster it was, yet it continued, and continued and continued.
To be fair none were prepared for the full onslaught of industrialized warfare.. Sheer and utter madness can be the only excuse. How does an entire continent go mad?