Soviet–Japanese border conflicts
The Soviet–Japanese border conflicts were a series of minor and major conflicts fought between the Soviet Union (led by Joseph Stalin), Mongolia (led by Khorloogiin Choibalsan) and Japan (led by Hirohito) in Northeast Asia from 1932 to 1939. The Japanese expansion in Northeast China created a common border between Japanese-occupied Manchuria and the Soviet Far East.
Source: Wikipedia — Soviet–Japanese border conflicts (CC BY-SA 4.0)