Between the wars, Japan had a slogan " Asia for the Asian". what did it mean

The slogan means that the Asian countries should be run by Asians, not by the European colonialists.

Explanation:

The Japanese slogan ''Asia for the Asian'' means that the Asian countries should govern themselves, not by European colonialists, and that the colonialists should retreat from Asia. This was due to the high level of European colonialism in this period in Asia, spreading in Southeast, East, South, and Southwestern Asia. The Europeans used these countries, their people, and resources, getting wealthy and living them on the verge of existence.

The Japanese despised this, and unlike the rest of the Asia countries they intervened on time, strengthened themselves both economically and military, and set them as an powerful country not to be messed with. The European colonialism in Asia was actually one of the prime factors that resulted in the manner in which Japan developed and became a very aggressive country in response.