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.
South Korea
South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korean Peninsula and lying to the east of the Asian mainland. The name "Korea" is derived from Goguryeo which was one of the great powers in East Asia during its time, ruling most of the Korean Peninsula, Manchuria, parts of the Russian Far East and Inner Mongolia, under Gwanggaeto the Great. South Korea lies in the north temperate zone and has a predominantly mountainous terrain. It comprises an estimated 51.4 million residents distributed over . Its capital and largest city is Seoul, with a population of around 10 million.