7. The Japanese expanded their presence in Manchuria throughout the 1920s
Japan had, since the end of the Russo-Japanese War, retained a lease on the South Manchuria Railway, granted to them in the Treaty of Portsmouth. The Japanese Showa government interpreted this to mean that Japan exercised all control of the region which the railway serviced. The Showa government, as had its predecessors, stationed Japanese troops along the railway, reporting them as railway guards to the League of Nations and the Chinese government. Japan also encouraged the settlement of Japanese immigrants to the region, as farmers and businessmen. These immigrants also included settlers from Taiwan and Korea, both Japanese possessions at the time.
In the late 1920s, the Chinese government began to assert its authority nationally, to the detriment of independent Chinese warlords. They also began to deny the Japanese settlers their property, or rather what they thought were their property, and refused compensation. This created tension between the governments of the two Asian nations which the nationalists in Japan decided to turn to their advantage. Japanese troops’ levels were increased at the end of the decade, with military units drilling in full view in the territories which the Japanese occupied. While the Chinese prepared to appeal to the League of Nations to resolve the dispute, the Japanese Army prepared a casus belli.
