Final answer:
Kim Il Sung was the Korean leader ordered by the Soviet Union to unite all of Korea under communist rule, an action that led to the Korean War when North Korea invaded South Korea with Soviet backing in 1950.
Step-by-step explanation:
The Korean leader who was directed by the Soviet Union to unite all of Korea under communist rule was Kim Il Sung. Following the end of World War II, Korea was divided into a northern communist segment under Soviet influence and a southern non-communist portion under American influence. In 1948, Kim Il Sung became the head of North Korea's Communist government after his appointment by Soviet officials. His government had the goal to reunify Korea under communist rule, which led to the outbreak of the Korean War.
Despite initial hesitations, Soviet leader Joseph Stalin eventually provided his support and military assistance to Kim Il Sung for an invasion of South Korea in 1950. This action instigated the Korean War, during which the North Korean forces, equipped with Soviet weapons and technical support, launched an offensive attempting to bring South Korea under communist control. However, the United Nations, largely influenced by the United States, responded with military intervention to repel the invasion.