So, I know that relations between the IJA and IJN were very poor, to the extent that the IJA had to purchase a few of it's own aircraft carriers to protect it's own supply shipping, being unable to rely on the IJN. But here's a question for you experts: -To what extent would the Army and Navy co-operate in the event that Japan was involved in a single front defensive war on the Asian mainland? In Manchuria for example, or Korea. To clarify, this would be in 1940/41.