Although Korea was once a united country, it is now divided into two separate nations along the 38th parallel. After World War 2, Soviet troops occupied the northern half of Korea while U.S. troops occupied the southern half. This led to the establishment of communist North Korea and capitalist South Korea. In 1950, North Korea attacked South Korea in an attempt to reunify the country under communist rule, but they were pushed back by U.S. and UN forces. Today, South Korea has a strong, developed economy while North Korea has a weaker, more isolated economy under the authoritarian rule of Kim Jong-il.