After all the books and papers written about the First World War (I've read quite a few of them), there is essentially one statement that summarizes everything that occurred:

SOCIETIES KILLED THEIR OWN YOUNG MEN
(scroll down for data supporting this statement)

If one can't say this--embrace the truth of this statement--then "further research" is futile.

If one embrace the truth of this statement, this opens up an understanding--makes it possible to understand--the other significant events that followed through the First Half of the 20th Century: Hitler, Nazism, the Holocaust and the Second World War.

Richard Koenigsberg

White, Matthew — First World War Casualties

Source: Historical Atlas of the Twentieth Century.