As soon as the war between North and South Koreas was broken out on June 25, 1950, except for six representative missionaries of the Korea Mission of the PCUSA, all the other missionaries including their children took the refugee to Japan via Pusan. Harold Voelkel also went to Japan with the missionary group. With the Incheon landing operation of the United Nations' Army commanded by General MacArthur, however, he was able to return to Korea as a civil chaplain and made efforts to rebuild the mission station in Seoul. Directly after some American missionaries returned to Seoul, they met in an inter‐denominational committee meeting, in order to discuss the problems of rebuilding the mission stations which had been severely damaged by the war. They firmly resolved to appeal each Mission Board in America to take part in a ‘Churches’ Crusade for Korea’ campaign. A few weeks later, the UN forces occupied Pyongyang, the centre of the Communist’s Korea, and the Executive Committee of the Korea Mission of the PCUSA became full of expectations that they could re‐take the mission stations in the North which had not been allowed to visit since 1941 by the banishment of Japan and, after its defeat in August 1945, by the refusal of the Soviet Occupation there. Directed by the Mission Board, Harold Voelkel made a tour of some mission stations in the North, in order to survey their situation. Soon after, however, the UN forces were forced to withdraw from the North by the attack of the Chinese People's Volunteer Army. Voelkel tried to persuade the US Commanders so that the Christians were able to take the refugee from Heungnam to Pusan, the South, because they were certainly expected to be persecuted by the Communists on their re-occupation. The so-called ‘Missionary Kids’ who were born and raised in Korea had supported the UN forces as staff by giving crucial information for their operations. For example, Horace G. Underwood, Jim Lampe and Bill Shaw played a crucial rule in the success of the Incheon Amphibious Operation which was carried out by General Douglas MacArthur. From the beginning of Incheon Operation, Harold Voelkel had been engaged in the evangelical works among the Prisons of War (POW). Some 140,000 POWs of People’s Army of North Korea were accommodated in the camps in Koje Island and, on the other, some 19,000 Chinese POWs in Cheju Island. The Board assigned Harold Voelkel to Koje for the evangelical purpose and Earle J. Woodbury, a former missionary to China, to Cheju. Their evangelical works were motivated in a strong anti‐Communist sense so that they were intended to convert the political stance of the Communists to Democracy. As the result of the evangelical activities by Voelkel and Woodbury, some half of the Korean POWs refused to return to the North and some 14,400 out of the 19,000 Chinese also selected to be repatriated to Formosa, instead of the Communist's China, at the expense of being separated from their families. This is why the evangelical movement of the missionaries in the POW camps were conceded in an anti‐Communist sentiment.