 On June 25 , 1950 , war broke out between the provisional governments of North and South Korea as they competed for control over the Korean peninsula . North Korea was supported by the People 's Volunteer Army ( <unk> ) of the People 's Republic of China and South Korea by the allies under the aegis of the United Nations which included the United States . The conflict is known as the Korean War . The 1st Marine Division was sent in and saw action in the Battle of <unk> Reservoir . In 1952 , 2nd Battalion , 9th Marines was reactivated and underwent training in Japan with the intention of participating in the conflict as part of the 3rd Marine Division . However an armistice was signed on July 27 , 1953 , and the unit did not deploy to Korea . Even though 2nd Battalion , 9th Marines did not actively participate in the conflict , the unit was awarded the Korean Service <unk> and National Defense Service Medal <unk> . The 3rd Marine Divisions headquarters was moved to Okinawa in 1955 and in 1959 the 2nd Battalion , 9th Marines returned to the 1st Marine Division . In 1960 , the battalion returned to the 3rd Marine Division in Okinawa . 
