The mongol conquests are going on, and they are blending cultures all over eurasia with each other. Ou now, against their will, they will run out of room to conquer any more in east asia. But the key, thewhole thing at ground zero was the japanese organization and military system. It was a cultural system, one might call it an organic system, that is often compared,. to the broad contemporary system in europe.
The Asia-Pacific War of 1937-1945 has deep roots. It also involves a Japanese society that's been called one of the most distinctive on Earth. If there were a Japanese version of Captain America, this would be his origin story.