<Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (February 2017) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (February 2017) (Learn how and when to remove this template message) </Td> </Tr> <P> This division of Korea, after more than a millennium of being unified, was seen as controversial and temporary by both regimes . From 1948 until the start of the civil war on June 25, 1950, the armed forces of each side engaged in a series of bloody conflicts along the border . In 1950, these conflicts escalated dramatically when North Korean forces invaded South Korea, triggering the Korean War . The North overran much of the South until pushed back by a US - led United Nations intervention . The UN forces then occupied most of the North, until Chinese forces intervened and restored communist control of the North . </P> <P> The Korean Armistice Agreement was signed after three years of war . The two sides agreed to create a four - kilometer - wide buffer zone between the states, known as the Korean Demilitarized Zone (DMZ). This new border, reflecting the territory held by each side at the end of the war, crossed the 38th parallel diagonally . </P>

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