Good point, Zonk. Since there is no WWI population surviving today and hasn't been for many years, it's not really something that's part of our consciousness. We're all well-versed in WWII as something that seems to have happened in "recent" history, but not so much with the first war. But WWI was absolutely horrific, and it was like no war Europe had ever seen. It was considered "the war to end all wars" for a reason. And when you look at the history, it was a rather pointless war and a situation that could have been solved diplomatically.
The generation that had to make decisions about what to do with Hitler had just lived through WWI a mere 20 years earlier. It was a very vivid memory, and Europe had not recovered physically, emotionally, psychologically, or financially. Quite naturally, no one wanted to live through anything like it ever again, especially not so soon. I still think appeasement was a terrible policy and this doesn't justify it - obviously, there were people who had lived through WWI who didn't take the appeasement attitude, like Churchill - but it's easier to understand if you remember the historical context.
Once the war started, the recent WWI history made it all the more horrifying. Unlike the start of WWI, when the general sentiment had been that the boys would be home by Christmas, everyone knew what kind of devastation was coming. It must have seemed to people that there would now be a vast world war everyone quarter century.
A story Queen Mum once told demonstrates the experience of the double wars for her generation: She was sitting somewhere next to the young Princess Margaret - I think it was a church service - and started to tear up over the war dead. Margaret turned to her with a look that seemed to wonder what was wrong, and the Queen suddenly recalled having the same moment with her own mother as a child. She wondered at the time if Margaret would have the same experience with her daughter in another 20 years.
