New guinea is a remote island in the pacific Ocean. It has towering mountain ranges, so tall that some planes can't quite make it over the hump. The area of malaya north of singapore is also valuable for its rubber and oil resources. To day these rich territories are independent nation states like asia and belgians. They remind you a little bit of the colonial power baboons who were colonised by the dutch east indies.
Japan's rising sun goes supernova and engulfs a huge area of Asia and the Pacific. A war without mercy begins to develop infusing the whole conflict with a savage vibe.