It really comes down to demographics. Losing so many men to death and injury resulted in a big drop in the birth rate. This big drop that rippled though the decades.
In France for example, people had big families before WW1. After the war, the birth rate decreased because there were fewer men, but the birth rate continued to be depressed well after the war because families had fewer children. The decline of the cultural influence of Christianity, overall rising affluence, and birth control are cited as the chief factors for lower bith rates. This became the norm which has persisted to this day.
The Muslim invasion is the final nail.
Islam is not the last thing, or the worst thing.
If Islam ever does dominate the world, everything will be fire, death and chaos.
The horror will be so complete that something new, and far more horrible, will be born after gestating within the seething mire.
Something that makes Islam look like a recipe for cupcakes.
And, they’re replacing them with....
WW1 was a drop in the bucket of self-murder....abortion. Began with 1931 contraception made possible by WW1 error.
I read an article recently which estimated that because of all the deaths France suffered, there were 300,000 fewer possible soldiers born to defend them against Germany. Of course, as stated elsewhere in this thread, if there hadn’t been a WW I, there wouldn’t have been a WW II, so in a sense it’s a moot point.