Germany on the move

I am reading The Guns of August about WWI and I can't understand what motivated the European nations in the cusp of their prosperity to fight each other to death. Much posturing and bayonet sharpening, and horses and honor, but why the enthusiasm? These days America is abandoning the NATO and the Europeans are preparing to defend themselves. I have not clear who is against whom. The initiative comes from Germany, that is rearming. Moreover, is recruiting its satellites into the Bundeswehr.

"So far, the low-profile and ad hoc approach of the Framework Nations Concept has worked to its advantage; few people in Europe have objected to the integration of Dutch or Romanian units into German divisions, partly because they may not have noticed. Whether there will be political repercussions should more nations sign up to the initiative is less clear."

 Some Germans must be thinking "The mustachioed psychopath is dead and his histrionics half forgotten - this time we shall succeed."

As a Jew, I hope there is nothing to worry about German power, although - who knows?