Operation Big Switch was the repatriation of all remaining prisoners of the Korean War. Ceasefire talks had been going on between Communist and UN forces since 1951, with one of the main stumbling blocks being the Communist insistence that all prisoners be returned home, with the UN insisting that prisoners who wished to remain where they were be allowed to do so. After talks dragged on for two years, the Chinese and North Koreans relented on this point, and the Korean Armistice Agreement was signed on July 27, 1953.