Kim Il-sung joined the Russian Communist Party

In order to escape the Japanese occupation of Korea as a child, Kim's parents escaped to Manchuria. He went to primary school in Manchuria and joined a communist youth group while still a student. Because of his involvement with the gang from 1929 to 1930, he was detained and imprisoned. Kim joined the Korean guerrilla resistance to the Japanese occupation sometime in the 1930s after being released from prison, taking the name of a famous prior Korean guerrilla warrior who had fought the Japanese. Kim was transferred to the Soviet Union for military and political training after being noticed by the Soviet military officials. He joined the Communist Party of the area there.

Kim served as a major in the Soviet army and oversaw a Korean contingent during World War II. Korea was effectively split in half when the Japanese surrendered in 1945, with the northern half under Soviet occupation and the southern half under American backing. In order to form a communist provisional government under Soviet supervision in what would later become North Korea, Kim returned at this time alongside other Koreans who had received Soviet training. In 1948, he was elected as the first prime minister of the newly established Democratic People's Republic of Korea, and in 1949, he was elected as the leader of the Korean Workers' (communist) Party.

The Soviet military establishment took notice of Kim because of his skill and accomplishment as a military officer. They extended Kim an invitation, inviting him to visit the Soviet Union to instruct military personnel. An interesting Kim Il-sung fact is that after his arrival, Kim joined the Russian Communist Party right away.