One of the coolest parts of Kaiserreich is that it doesn't adhere to the strict bipolar (or perhaps tripolar if you separate the Comintern from the Allies) structure of the post-WWI world of OTL. Instead you have multiple alliance structures continuing even after the Weltkrieg. As far as I can tell, they are:
Mitteleuropa + colonies
Syndicalist Internationale
Entente
Catholic League
What else is there? Does Russia form an alliance with former imperial states? Does Japan join anything?
Mitteleuropa + colonies
Syndicalist Internationale
Entente
Catholic League
What else is there? Does Russia form an alliance with former imperial states? Does Japan join anything?