After World War II when Japan surrendered to US, Korea was divided into two occupation zones in 1945, with the United States administering the southern half of the peninsula and the Soviet Union taking over the area north of the 38th parallel. The politics of the Cold War resulted in the 1948 establishment of two separate nations with opposed political, economic, and social systems. In 1950 the Korean War broke out when North Korea breached the 38th parallel line to invade the South, ending any hope of a peaceful reunification for the time being.