The scenario assumes that the Second Sino-Japanese War did not continue and that Japan joined the Allies on 25 June 1940. Japanese troops would probably remain in Manchuria, but the army would not be committed to the wider war in China. Without that conflict, the United States would have a weaker case for imposing the same embargoes on Japan. Relations between Washington and Tokyo would remain uneasy, while leaving Japan more room to choose cooperation with Britain.
Chapter · 5:59-7:31
Removing the war in China changes Japan's strategic choices
The scenario begins by removing the Second Sino-Japanese War, weakening the chain of embargoes and confrontation that historically pushed Japan toward war with the United States.