Neither the army nor the navy are even unified as a service. They're faction ridden. The imperial way faction wants to take manchuria and move on up to the soviet union. There's a japanese concept called gekojo, and it's difficult to understand. It provides an opportunity for junior officers to high jack policy here in a way that would be impossible in most great powers.
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.