In 1930, the Soviet Union stopped Buryat migration to the Mongolian People's Republic to prevent Mongolian reunification. All leaders of Mongolia who did not fulfill Stalin's demands to perform Red Terror against Mongolians were executed, including Peljidiin Genden and Anandyn Amar. The Stalinist purges in Mongolia, which began in 1937, killed more than 30,000 people. Choibalsan died suspiciously in the Soviet Union in 1952. Comintern leader Bohumír Šmeral said, "People of Mongolia are not important, the land is important. Mongolian land is larger than England, France and Germany".