The Republic of Korea, or South Korea, consists of the southern half of the Korean peninsula in East Asia and many islands lying off the western and southern coasts. The largest island, Jeju, has the highest mountain in South Korea at 1,950 meters (6,398 feet). The terrain is mountainous, though less rugged than that of North Korea.

Major population and industrial centers are located in the northwest (Seoul-Incheon area) and southeast. To overcome distance and traffic congestion, South Korea launched a high-speed rail service between Seoul and Busan in 2004. English is taught as a second language in most schools, and more than 1.5 million ethnic Koreans reside in the U.S. In 2000 the government introduced a new phonetic system for transcribing Korean into English, changing names like Cheju to Jeju and Pusan to Busan.

Starting in the late 1970s this capitalist prodigy matured into the world's 12th largest trading nation and a major exporter of cars, consumer electronics, and computer components—due in part to huge export-oriented conglomerates called jaebols. From 1980 to 1990 economic growth averaged 10 percent a year—more than three times that of the U.S. and twice that of Japan. However, the Asian financial crisis caused a deep recession. Economic growth rebounded in 1999, and the economy continues to perform well thanks to vibrant exports.

After the Korean War, South Korean society has shifted from being 75 percent rural to being 82 percent urban. Since 1987 it has grown as a multiparty democracy, and the government has pursued peace initiatives and trade with the unpredictable North Korean regime. Road and railway projects are under way to link the two Koreas, and in 2003 more than half a million South Koreans visited the North—and 1,023 North Koreans traveled to South Korea, mainly for joint sporting events. The potential military threat posed by North Korea keeps some 37,000 U.S. troops here.