I can't get over the lack of knowledge regarding WW2.
"Engage Japan more comprehensivly" you say. Before attacking the US in an attempt to destroy our Pacific fleet at the same time their diplomats were discussing peace in Washington The Japanese had brutally Invaded China, Korea, Manchuria, Indo-china, Indonesia, Thailand, and Burma. They were heading to vanquish the Philippines and many Islands in the Marshalls group such as Guam and Midway. There were no "Other Nations" as they also attacked and won
Singapore and declared war on Great Britain. They were heading for Australia. The small Australian army was in Europe fighting the Germans to defend England. They also took over the French and Dutch colonies. They were also attacking the Aleutian Islands in Alaska. We in American hardly had an army. navy or air force. Most of what we had was committed to stopping Germany from taking over England and Russia.
Please...read a book.