Operation Big Switch was the repatriation of all remaining prisoners of the Korean War. Ceasefire talks had been going on between the North Korean, Chinese and United Nations Command (UNC) forces since 1951, with the main point of contention being the repatriation of all prisoners to their home countries, in accordance with Article 118 of the 1949 Geneva Convention. China and North Korea wanted prisoners to be compulsorily repatriated as outlined by the Geneva Convention but the UNC insisted 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 27 July 1953.
Negotiations
On 28 March 1953, replying to UNC Commander General Mark W. Clark's request for the exchange of sick and wounded prisoners, North Korean leader Kim Il Sung and PVA commander Peng Dehuai said that they were perfectly willing to carry out the provisions of the Geneva Conventions in this respect. On 30 March Zhou Enlai, the Foreign Minister of China, issued a statement urging that both sides "should undertake to repatriate immediately after the cessation of hostilities all those prisoners of war in their custody who insist upon repatriation and to hand over the remaining prisoners of war to a neutral state so as to ensure a just solution to the question of their repatriation." In a letter to Kim and Peng on 5 April, Clark proposed that the liaison officers meet the following day and requested that Kim and Peng furnish the UNC with more particulars on the communist method for disposition of the non-repatriation question. In preparation for the first meeting of the liaison officers on the arrangements for the transfer of the sick and wounded, Clark and his staff formulated a UNC plan. It contemplated that each prisoner to be exchanged would be brought to Panmunjom, furnished with a medical tag on his condition and treatment and given unmarked, serviceable clothing.
On 6 April, Rear Admiral John C. Daniel and General Lee Sang Cho led the liaison officers groups when they gathered at Panmunjom. The UNC was ready to start immediate construction of the facilities necessary for the delivery and receipt of the sick and wounded at Panmunjom and to begin delivery of 500 prisoners a day within seven days of the agreement on procedures. To expedite matters Daniel suggested that each side turn over its lists of names and nationalities of the prisoners to be exchanged and that officers be appointed to discuss administrative details. Lee pointed out that the Communists wanted to repatriate all sick and wounded eligible under Articles 109 and 110 of the Geneva Conventions. On 7 April, Daniel informed the Chinese and North Koreans that the UNC was prepared to repatriate all prisoners eligible under the two articles, subject to the proviso that no individual would be repatriated against his will. Daniel stressed that the UNC would give the broadest interpretation possible to the term "sick and wounded." On 11 April, an agreement was reached that within ten days the exchange at Panmunjom would begin, with the Chinese and North Koreans delivering 100 and the UNC 500 a day in groups of 25 at a time. Rosters prepared by nationality, including name, rank, and serial number would accompany each group and receipts would be signed for a group as it was turned over to the other side.