Answer:
the invasion and occupation of North Korea by the Soviet Union during World War II
Step-by-step explanation:
The peninsula was ruled by the Korean Empire until it was conquered and colonized by Japan after the Russo-Japanese war of 1905. In 1945 - just after World War II - the peninsula was divided into two zones, the north occupied by the Soviet Union and the southern part occupied by the United States. In 1948, North Korea refused to participate in the elections held under the United Nations, finally creating two independent governments in each of the occupied areas. Both states claimed the entire peninsula as their own territory, which would lead them to the Korean war in 1950, which ended with the signing of an armistice in 1953; officially, the two countries are still at war, as a peace treaty has not yet been signed.