Answer:
Several regions of Asia and the Pacific Ocean were European colonies or possessions, such as Indochina, Vietnam's former name, then a French possession, Indonesia, then Dutch possession, and Singapore, then English possession. Japan wanted to follow the example of the European colonialist powers.
When Hitler began his war in Europe, the Japanese found an opportunity to transform these European colonies in Asia and the Pacific into Japanese colonies. So while England, France, and the Netherlands were very busy with the problems caused by Nazi Germany, Japan took the opportunity to conquer the territories in which it was interested.
