Korea is a region of Asia that is just south of China and the Soviet Union. It is a peninsula that reaches out towards Japan. Japanese forces during World War II occupied Korea. After the war was over the country was split with a Russian and Chinese backed North Korea and South Korea backed by the United States. In the early 1950's, the two countries (and their backers) fought in what is called the Korean War.
While Cate Archer was infiltrating the Dumas Lumber Company location within the state of Washington she overheard two H.A.R.M. thugs talking about experiences in the Korean War. One of the thugs had been a member of the U.S. Marine Corps while in Korea.
Korea on Wikipedia