Deportation of Koreans in the Soviet Union, originally conceived in 1926, initiated in 1930, and carried through in 1937, was the first mass transfer of an entire nationality in the Soviet Union. Almost the entire Soviet population of ethnic Koreans (171,781 persons) were forcefully moved from the Russian Far East to unpopulated areas of the Kazakh SSR and the Uzbek SSR in October 1937. The official reason for the deportation was to stem "the penetration of the Japanese espionage into the Far Eastern Krai", as Koreans were at the time subjects of the Empire of Japan, which was hostile to the Soviet Union. Estimates based on population statistics suggest that 40,000 deported Koreans died in 1937 and 1938 from starvation, exposure and difficulties adapting to their new environment.