How did imperialism end in Japan?

Between 1900 and 1905, Japan became a full-fledged member in the club of imperialist powers. Japan's imperial expansion in the 1930s was due to the long-term view taken by the country's military elite, argues Louise Young, author of "Japan's Total Empire." The Portsmouth Treaty to end the war gave Japan control of Korea and the Kwantung Leased Territories. Japan stood as one of the world's powers with a colonial empire of its own. Japanese military leaders believed that seizing control of areas like Korea was vital to securing Japan's security in the East Asia region.