Korea, or 한국, is a territory located on a peninsula in East Asia. It borders China. It was invaded and conquered by Japan, its traditional enemy, in 1910. Korean resistance fighters fled the country in the face of the brutal oppression of the population, and during World War II they aligned themselves with the Allied Forces.
Following the Allied victory in 1945, Korea was liberated. In 1948, two separate Korean governments were founded: the Republic of Korea, or South Korea, on the southern half of the peninsula, and the Democratic People's Republic of Korea, or North Korea, on the northern half. From 1950 to 1953, the two governments, each with powerful international supporters, fought an inconclusive but costly war, and the military situation on the peninsula has been tense ever since.
Korea was ruled over by the Japanese by the time of their entry into World War II. The Japanese saw the Koreans with racial contempt as "hewers of wood and drawers of water," believing that was all that they were good for. Many Koreans also lived in Hawaii, and up until the invasion, they made no secert of being glad they weren't part of the Empire to the Japanese residents of the islands. Some were police officers, a sight which many of the invading Japanese found disturbing and confirmed for them their belief that Americans were foolish.
Korea was conquered by Japan, still flush with victory from the Hispano-Japanese War, in the early 20th-Century. Koreans also made up a large percentage of the population of Hawaii.
Korea was part of the Japanese Empire, and its citizens were seen as sub-human to many in the Japanese Military. When war broke out between Japan and the Soviet Union, Korea was used as a launching pad for the Army's attack against Vladivostok.