South Korea–United States relations
Following Japanese surrender at the end of the Second World War, the Allied Powers divided the Korean peninsula along the 38th Parallel with two occupation zones with the United States in the south, and the Soviet Union in the north that would later become North Korea. On August 15, 1948, the southern half of Korea declared independence as the Republic of Korea with Syngman Rhee as president. The United States recognized the Republic of Korea as an independent state on January 1, 1949 and diplomatic relations between two countries were established on March 25 in the following year.
Cross-border skirmishes and raids at the 38th Parallel escalated into open warfare when the North Korean forces invaded South Korea on June 25, 1950. The Korean War broke out when North Korea invaded South Korea. In response, 16 member countries of the United Nations, including the United States, came to the defense of South Korea. It was the first significant armed conflict of the Cold War with extensive deployment of American and other troops.
Supreme Council for National Reconstruction
The Supreme Council for National Reconstruction, initially named the Military Revolutionary Committee, was a military junta that oversaw the government of South Korea from May 16, 1961 until the inauguration of the Third Republic of South Korea in 1963. It was composed largely of military officers who were involved in or supportive of the May 16 coup which overthrew the Second Republic of South Korea. The council was chaired initially by Chang Do-yong, and subsequently by Park Chung-hee. The president of the Second Republic, Yun Po-sun, stayed in office as a figurehead.