The sudden defeat of the Japanese military against the allied forces temporarily brought about a power vacuum in the Korean peninsula right after the announcement of unconditional surrender by the Japanese Emperor in August 15, 1945. While the United States prepared for the occupation of Japan during the Second World War, it did not have any specific plans for Korea, a former Japanese colony. The Supreme Commander for the Allied Power (SCAP) under General Douglas MacArthur launched massive de-militarization policies to transform the Japanese society from the beginning of occupation of Japan. But the United States of America Military Government in Korea (USAMGIK) was formed by the 24th US Army Corps without any blueprints for occupation of South Korea. Originally the 24th Army Corps of the United States was planned to occupy Japan after it successfully invaded Okinawa. But it was suddenly redirected toward Korea without any preparation for the occupation of Korea in advance. The US considered Korea not as an independent state but as a colony of Japan.
The 24th Army Corps moved to the southern part of the 38th parallel in Korea in September. Thus, the Soviet army occupied the northern part of the 38th parallel, whereas the US army occupied the southern part of the 38th parallel in Korea. The division of the Korean peninsula by the Soviet Union and the United States was the beginning of the long and turbulent saga of anti-communism in South Korea. As the Cold War between the communist bloc and the capitalist bloc escalated more, the Korean peninsula became the forefront of the military conflicts between the Soviet Union and the United States that lasted from 1948 to 1992.
The formation of anti-communism at the early stage in South Korea was a complex outcome of interplay of many factors: The domestic politics in South Korea and the role of the USAMIK, the rise of anti-communism in the American politics, and the intensification of the international conflict between the Soviet Union and the United States after 1945. The domestic politics under the trusteeship of the USAMIK was the beginning of the formation of anti-communism in South Korea. Anti-communism in South Korea was led by the Korean elite who supported the Japanese colonial rule in the colonial period. The SCAP in Japan launched sweeping reform policies to get rid of the militarist institutions and policies, executing war criminals including military, business oligarchs and bureaucrats (Cohen 1987; Gordon 1993). At least until 1947, when the reverse course was taken by the SCAP, demilitarization and democratization were the two most important keywords representing the policy principles of the SCAP in postwar Japan (Hanneman 2013: 84-98). Extensive reform policies in education, business, politics and military were launched by the SCAP. Thus massive reforms had continued until the reverse course, reviving major economic and political groups to face the threat from the USSR, was taken by the SCAP.
In contrast, there was no purge of the pro-Japanese groups and social elites in South Korea at that time(Lee 2010). Furthermore, the USAMG recruited officials for the military government among former administrative staff who were working for the Japanese Governor General in Korea. The USAMG didn’t have any information or knowledge about Korea. It recruited Koreans with experiences of administrative works including police men. Thus, Koreans working for Japan were not purged at all. Instead, they could maintain their positions and power even after the liberation from Japan in August, 1945. Only thing that changed was their affiliation from the Japanese Governor General in Korea to the United States of America Military Government. It betrayed the expectations of the people, that is, the purge of traitors. The return of traitors to power became a source of anger and protests of the people in 1946. However, the ruling elite and the USAMG considered local protests as communist insurgency supported by the Soviet Union or the North Korean communist party (Cumings 1981; Moon 2005, 23-44).
The shift of domestic politics in the United States strongly affected the postwar policy in South Korea as well as Japan. Harry Truman who succeeded Franklin Roosevelt adopted the Truman Doctrine which attempted to contain Soviet expansion. It was a radical shift of the relationship between the USA and the Soviet Union from the wartime alliance during the Second World War to the peacetime enemy in the postwar period, signaling the beginning of the Cold War. George Kennan’s containment policy against the Soviet Union was implemented in East Asia as well as Western Europe (Kennan 1947). Thus, the comprehensive reform in Japan was halted in 1948. Accordingly, there was a fundamental shift of principles of occupation policy of the SCAP from demilitarization and democratization to rebuilding Japan as a front of anti-communist expansion in Asia, by reviving the old imperial elites as well as Japanese big corporations. The restoration completely changed the occupation policy of the SCAP to make Japan a bulwark against the Soviets (Cumings 1988: 247). American staff and advisors in the SCAP in the reform period, mostly New Deal liberals (Takemae 1988: 93-96), were suspicioned of some connection with communists by George Kennan (Cohen 1987; 415-416). Thus, so the called “reverse course” by the SCAP took place more bluntly in Japan (Cumings 1993: 34-63).
After 3 years of trusteeship of USAMG, South Korea could establish an independent government in August, 1948. In 1948, the First Republic introduced the National Security Law (NSL) which purported to promote national security by outlawing any activities that might be beneficial to communist activities and eventually North Korea. Illegal activities included anti-state activists, dissemination of communist ideas, organization of communist groups, etc. The NSL had been frequently used to oppress political opposition by the Syngman Rhee government. For example, Syngman Lee got rid of Bong Am Cho, the chairman of the Progressive Party, who was the rival to Syngman Rhee in the 1956 presidential elections. He proposed a peaceful unification policy which was far different from Syngman Rhee’s unification policy by military invasion. In 1959, Bong Am Cho was charged of violation of the National Security Law. He was executed right after the verdict by the court without due process. Any other anti-government activists were accused of violating the National Security Law under the Syngman Rhee government.
The National Security Law was completely abolished in Arpil 19, 1960 when Syngman Lee stepped down as president and fled to Hawaii after the nationwide student protests against his dictatorial rule. However, after two months the new National Security Law was established with significant revision or deletion of some codes violating civil rights. Another significant revision of the NSL was done in 1991 when the Socialist bloc in Eastern Europe was dissolved and the Cold War System had been disappearing. One of key changes was that the NSL should be confined to organizations or associations to overthrow the government. Those who do not report those organizations are not penalized anymore by the revised NSL in 1991.
The Anti-communism Law was another institutional component of anti-communism in South Korea. The military government which replaced civilian government by the military coup in May 16, 1961 introduced the Anti-communism Law. Claiming anti-communism as the national policy, the military government attempted to punish opposition movements affiliated with or affected by communist organizations. It made appraisal and incitement of communism illegal. It also made those who knew someone violating the Anti-communism Law but did not report them to the police punishable.
However, the Anti-communism Law was revised several times because it overlapped with the NSL and outdated with the change of international relations in December 31, 1980. The normalization of diplomatic relationship between the USA and communist China shattered the ideological core of anti-communism. In addition, the withdrawal of the US army from Vietnam in 1975 was another shock to the authoritarian regime in Korea. The military regime strengthened its ideological control by terrifying opposition movements and ideological challenges. The reign of terror by secret police and intelligence organizations for surveillance of the people was intensified. However, it was abolished in December 31, 1980, when the new military regime seized the power after president Park Chung-hee was assassinated by the chief of Korea Central Intelligence Agency (KCIA). Mainly because the Anti-communism Law overlapped with the NLA, the Anti-communism Law was abolished and some parts of the Anti-communism Law were transferred to the National Security Law.