Korean reunification selected the 38th parallel as a dividing line. Japanese troops to the North of this line were to surrender to the Soviet Union and troops to the South of this line would surrender to the United States. This was not originally intended to result in a long-lasting partition, but Cold War politics resulted in the establishment of two separate governments in the two zones in 1948 and rising tensions prevented cooperation. The desire of many Koreans for a peaceful unification was dashed when the Korean War broke out in 1950. In June 1950, troops from North Korea invaded South Korea.
Canada in the Korean War in the objective that it had set with the United Nations forces. In April 1951, Chinese forces of the 118th Division attacked the Kapyong Valley in force, and pushed South Korean and New Zealand troops into retreat. Under heavy pressure, the Korean 6th Division broke, and the line collapsed. American and South Korean men poured through a gap under protective covering fire from Australians who were holding their section of the line despite heavy pressure. The 3rd Battalion, Royal Australian Regiment (3 RAR) and 2nd Battalion, Princess Patricia's Canadian Light Infantry (2 PPCLI) were ordered to halt this Chinese advance.