Paper short abstract:

Japan's imperial expansion has generally been associated with the events after the Manchurian Incident in 1931. Yet, Japan's continuous territorial expansion also occurred from 1894 to 1922. I explain the dynamics of this expansion, focusing on the principles of modern Japanese diplomacy.

Paper long abstract:

Japan's imperial expansion has generally been associated with the events after the Manchurian Incident. Yet, Japan's continuous territorial expansion also occurred from 1894 to 1922. During that period, Japan acquired Taiwan, the South Sakhalin, and, in effect, the South Sea Islands, annexed Korea, and had a special influence on the North East district of China.

The commonly accepted theory concerning modern Japan's diplomacy and its imperial expansion is that Japanese leaders found themselves in a world of ruthless competition and went along realistically with the stream of imperialism. However, leading Japanese diplomats understood the practical significance of norms in international relations, and pursued Japan's national interests, which were closely tied with international rules and norms.

Leading Japanese diplomats eagerly pursued national interests, which could include not only economic profit but also concession and territorial cession. Yet, the word interest often had an implication of mutual benefit or a spirit of compromise, and did not solely mean Japan's self-interest. Another concept on which they placed a high value was justifiability. They hesitated to make baseless claims or to take military actions without justification. However, it does not mean that they always tried to do what was ethically right, and once they concluded that they were justified in following a certain course, they did not hesitate to take military measures or to make demands on a territory. As attaching importance on the notions of interest and justifiability, leading Japanese diplomats, at least subjectively, refrained from making excessive demands in international relations. This mentality can be called a belief in "fairness." One of their typical ways of thinking based on this spirit was that if, for instance, Russia gained something in Manchuria, Japan had a right to acquire something in Korea. The leading diplomats' belief in the notions of interest, justifiability, and "fairness" formed Japan's motive for international cooperation and at the same time led its imperial expansion. Current studies on Japanese imperialism chiefly pay attention to social and cultural spheres, but this paper shows a new explanation on the dynamics of its imperial expansion with a classical approach.