Korean War two years of fighting became a war of attrition, with the front line close to the 38th parallel. The war in the air, however, was never a stalemate. North Korea was subject to a massive bombing campaign. Jet fighters confronted each other in air-to-air combat for the first time in history, and Soviet pilots covertly flew in defense of their communist allies. The fighting ended on 27 July 1953, when an armistice was signed. The agreement created the Korean Demilitarized Zone to separate North and South Korea, and allowed the return of prisoners. However, no peace treaty was ever signed,
Australia in the Korean War and the United Nations Security Council asked its members to help repel the North Korean attack. Australia immediately contributed No. 77 Squadron RAAF and the 3rd Battalion, Royal Australian Regiment (3 RAR), both of which were stationed in Japan under the British Commonwealth Occupation Force (BCOF). No. 77 Squadron converted to P-51D Mustang fighters before arriving in Japan in February 1946 to participate in the British Commonwealth Occupation Force. Occupation duties proved uneventful, and No. 77 Squadron was preparing to leave Japan for Australia when the Korean War broke out in June 1950. 77 Sqn was immediately dispatched to Korea,