Why North Korea & South Korea Are Separated

A UNIFIED KOREA

For centuries before that point, the peninsula was a single, unified Korea, ruled by generations of dynastic kingdoms. Occupied by Japan after the Russo-Japanese War in 1905 and formally annexed five years later, Korea chafed under Japanese colonial rule for 35 years—until the end of World War II, when its division into two nations began. “The catalyzing incident is the decision that was made—really, without the Koreans involved—between the Soviet Union and the United States to divide Korea into two occupation zones,” says Michael Robinson, professor emeritus of East Asian Studies and History at Indiana University, who has written extensively on both modern Korea and its history.