The country that controlled Korea when World War II began is JAPAN.
<h3>Further explanation
</h3>
Japan formally annexed the Korean Empire after The Japan- Korea Treaty or Japan-Korea Annexation was signed in 1910. Japanese ruled the Korean Peninsula ended on 15 August 1945 when Japan surrendered in World War II. Soon after World War II ended, the Korean peninsula divided into two countries, North Korea which is communist under the Soviet Union and South Korea, democratic, under the United States.
During the annexation, Korean suffered a lot. Korean culture and language suffered heavy losses. The Japanese aimed for the eradication of the Korean race. There is still a lot of dispute between Japan and Korea in many aspects until today.
Despite these disputes, the relationship between South Korea and Japan re-establish in 1965. Japan-South Korea maintains the relation in many aspects: education, trade, and tourism. Until now, South Korea continues to request Japan's apologize and compensation for Korea colonization under Japan. Whereas, there is no diplomatic or economic relation between North Korea and Japan.
<h3>Learn more
</h3>
Korean War brainly.com/question/10905733
Korean War brainly.com/question/1351858
Korean War brainly.com/question/1083893
Keywords: Korean history, World War II, Korean War, Korean, The Japan-Korea Treaty