Answer:
It did not have to fight the majority of US forces.
Step-by-step explanation:
Japan was able to expand its territory because of its victory over Russia and China and many other Asian countries. During WW II, Japan became part of the Axis Power and was military strong which help them to conquer many Asian countries. Another reason was that the European were busy in the war that started in Europe between the German and Allied. So, nobody paid much attention to Japan.