The movie is about China's role in the Korean War of 1950-1953. China had joined Russia in supplying arms and men to North Korean forces, which had invaded South Korea. America supported South Korea, and the 1953 armistice between the two sides resulted in the permanent division between North Korea and South Korea. With a total death toll exceeding 1 million deaths, and Korean civilian deaths accounting for the majority of those deaths, it was the fifth bloodiest war in U.S. history.