I wonder if Germany wouldn't have actually been the ~lone~ superpower. The USA didn't really achieve "superpower" status until after WWII. Had there been no participation in WWI and no WWII there would have been no massive buildup of ships and materiel and men.
It may be imponderable, but there's a real possibility that the big superpowers of the 20th Century would have been Germany and Japan. Not sure how that would have played out.
Undoubtedly the way that the Germans and Japanese intended it to before WWII, with Japan in charge of The Greater East Asia Co-Prosperity Sphere and Germans in charge of Western Europe and Britain's colonies in the Middle East.