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.
United Nations Security Council Resolution 82
At the end of World War II, the Korean Peninsula, which up to that point had been occupied by the Empire of Japan, was divided along the 38th Parallel. To the north, the Soviet Union (USSR) occupied the country, which established itself as a communist state, the Democratic People's Republic of Korea under Kim Il Sung. To the south, the United States (US) occupied the country, establishing the Republic of Korea under an autocratic anti-communist leader, Syngman Rhee. As tensions rose between the US and the USSR, each government in Korea claimed it had sovereignty over the whole country.