Region: Middle Earth
Yes. I read back through my post and I don't think I made it clear that's what I was talking about...
The hobbits return to the Shire, and their inability to rejoin society. On one level, the Shire itself had been touched by Saruman's industrial warfare, and so was a changed place from that which they remembered. And on another level, they themselves had been touched by their great ordeal, and were returning quite traumatized, especially Frodo.
I am unsure. I could easily see both being true. Certain theatres of WWI sounded like about the height of human suffering yet seen on our sorry planet. And then, as you say, Europe was forever changed, not just physically by the war machine, but the massive social changes, as well.
It must have been a mind-boggling time to live through and attempt to make sense of. Those who accuse the "appeasers" for allowing a second world war to break out, just don't comprehend the experiences of those who lived through the first and the lengths they were willing to go to avoid seeing such a thing reoccur.
A strange reading recommendation: " Rites of Spring: The Great War and the Birth of the Modern Age" by Modris Eksteins. Doesn't involve Tolkien, if memory serves. But a pretty wild look at the origins and outcomes of WWI. The thesis may not exactly hold, but I think the journey is worth the read, regardless.