While surfing through you tube, came upon a BBC rare documentary on the fall of Singapore. In reality, the documentary seems to dwell more on two UK. military ranking officials who later used there military knowledge to build up Japans Naval Air Power. They also sold, at least one of them, UK. weapon plans and tech information. In other words, without there help Japan might not have developed Naval air power and carriers which equaled the UK. Thus, WW II and the millions in casualties it cost in Asia might have been avoided. The Japanese attack on the US might also not have happened.Yes, it seems UK. sources also informed the Japanese on the US base in Hawaii. Has for Singapore, a UK. intel officer recommended less artillery and more fighter airplanes since he checked the area and believed that a land attack of Singapore was most likely. His suggestion was not taken and he was retired for his trouble. This documentary really dwells on things you do not hear in history books. And yes, the UK. intel knew about these people since the 1920's but because of royal titles and not wanting to give up there sources they did nothing. Later it even seems the UK. PM during WW II tried to cover up the doings of at least one of the persons, the one with the royal title.
You got to see this documentary. It does seem the War in the Pacific could have been avoided.
This will take you to it - https://www.youtube.com/watch?v=VVpAN_lQgcA