I submit that WWI was necessary, given the rules of the time, and Germany’s refusal to abide by the rules of war.
They didn’t intend to lose, and thought that their cheating would not be punished after the war was over if they won. Also in WWII they were the same way, as Manstein/Lewinski was the nephew of Hindenburg, and had the same idea of laws of war (lie as necessary to avoid punishment afterwards, and emphasize differences between the victors).
Was there some reason why Britain had more "right" to have an Empire than did Germany?
Granted the Kaiser was not a lovable character, and the maladroit Zimmerman Note was no help. But WWI in the best interests of the US? No way.