score:2
Yes, the Japanese garrison could have fed itself because this is enough square miles to feed such a number of troops.
However, this does not change at all the issue of the war: New Britain offered no facilities for the development of ammunition nor military material, so the Japanese garrison in New Britain would have still been blockaded and bombed by the US until the capitulation in 1945.
Upvote:1
Umm, the Japanese garrison at Rabaul did feed itself, especially compared to other Japanese garrisons in the Pacific (Truk was not terrible, but in much worse shape than Rabaul. Islands in the middle of the Pacific like Jaluit were in horrible shape.) As articles linked by others note, Japanese soldiers became highly proficient farmers and fishermen. As the Australian general who accepted the Japanese surrender at Rabaul remarked, Rabaul achieved virtual self sufficiency "like a small independent country." Doubtful that many, if any, Japanese at Rabaul actually "starved, " while there are far better known cases elsewhere.