Besides, Imperial Japan had its eye on British and French colonies. Japan wanted to rule its sphere, which required cutting down the British and French.
Germany also tried to use Japan as an ally against the Soviet Union, but Japan declined. So it’s unlikely Japan would have been our ally against the Soviets.
Because Zhukov kicked Japan’s ass in the 1939 Battle of Khalkhin Gol. Probably the most significant battle of WWII that few know about, but had huge ramifications during and after WWII.