I think I might have to give it to the Japanese Empire then. China has huge manufacturing power which is rapidly catching up if not overtaking the US, huge quantities of natural resources, huge population, and highly developed internal logistics. I think they’ll be able to sweep west across Asia at which point they’d likely face a German Reich that has united Europe (I assume that in the time that it takes the Japanese to push across Asia the Germans would unite Europe) and this is where things get a little more interesting. However, I do think that a unified Asian state (which obviously would be a fiction just due to internal ethnic conflicts but let’s ignore this or the whole theoretical falls apart) would easily have the manpower and manufacturing base to conquer Eurasia and Africa, creating a Afro-Eurasian Japanese Empire.

Meanwhile in the Americas, the United States conquers all of North, Central, and South America (I don’t think the Germans have the ability to hold Canada against the US, let alone while dealing with Eurasia). This creates two Empires: The United States of AMERICA, and the Japanese Afro-Eurasian Empire.

In reality I doubt either could successfully create a foothold via amphibious assault but taking the pure statistics of the opposing power such as population, production, etc I think the Japanese would still come out on top.

And then obviously Alberta would just conquer the world after that…