TheVietnamese Demilitarized Zone, abbreviated asV-DMZ, was ademilitarized zone at the17th parallel inQuảng Trị province that was the dividing line betweenNorth Vietnam andSouth Vietnam from 21 July 1954 to 2 July 1976, whenVietnam was officially divided into twode facto countries, which was twode jure military gathering areas supposed to be sustained in the short term after theFirst Indochina War.
During theVietnam War (1955–1975) it became important as the battleground demarcation betweencommunist North Vietnam andanti-communist South Vietnam. The zonede jure ceased to exist with the reunification of Vietnam in 1976 (de facto in 1975).
The border between North and South Vietnam was 76.1 kilometers (47.3 mi) in length and ran from east to west near the middle of present-day Vietnam within Quảng Trị province.[1] Beginning in the west at thetripoint withLaos, it ran east in a straight line until reaching the village of Bo Ho Su on theBến Hải River. The line then followed this river as it flowed in a broadly northeastwards direction out to theGulf of Tonkin. Either side of the line was a Demilitarized Zone, forming a buffer of about 6.4–9.7 kilometers (4–6 mi) in width.[1] Although it was nominally described as being at "the17th parallel," the border never actually followed that line, only straddling the general area of that line of latitude.
TheFirst Indochina War (also called the French Indochina War) was fought inFrench Indochina where was usually and shortly called "Indochina" from 1946 to 1954 between theFrench Union (including the anti-communistState of Vietnam) aided by the US on the one side, and thecommunist-dominatedViet Minh/Democratic Republic of Vietnam and allies (aided byChina) on the other.[1] The Viet Minh won the war after theirvictory in Dien Bien Phu on 7 May 1954. On 21 July 1954, the State of Vietnam gave up its control of Vietnam whenthe agreement betweenFrance and the Democratic Republic of Vietnam inGeneva took effect, Vietnam wasde facto divided into two countries: North Vietnam (Democratic Republic of Vietnam, capitalHanoi) and South (State of Vietnam, capitalSaigon).[1]
The postcolonial conditions of Vietnam were set at theGeneva Conference of 1954, and an agreement about Vietnam (as parts of the three agreements about French Indochina) was signed between France and the Democratic Republic of Vietnam on 21 July 1954.[1] The agreement reflected the military situation on the ground: the northern part of Vietnam, which was almost entirely controlled by the Viet Minh, became the Democratic Republic of Vietnam, under the communist leaderHo Chi Minh. The southern part of Vietnam, where the Viet Minh controlled only relatively small and remote areas, became the independent State of Vietnam underBảo Đại, the last scion ofthe old Vietnamese imperial house. The State of Vietnam later became theRepublic of Vietnam after the1955 South Vietnam referendum, ruled byNgo Dinh Diem. A temporary boundary, running primarily along the Ben Hai River was established pending elections, with the area on either side of the border declared a demilitarized zone. Troops of both governments were barred from that area.[2]
Afterwar between North and South Vietnam broke out in 1955 – one year after the division – the DMZ hardened into ade facto international boundary. The war itself evolved into aproxy conflict of theCold War and millions ofAmerican and allied soldiers were sent to the country to help the anti-communist government of South Vietnam against communist North Vietnam from 1965 to 1973. Despite the DMZ's supposed status, 3rd Marine Division intelligence estimated that the combat strength ofNorth Vietnamese Army and theViet Cong (a nominally independent militant group aligned with North Vietnam against the South Vietnamese government) in the DMZ area in January 1968 was 40,943 troops.[3]
The North was ultimately victorious in the war and the Republic of Vietnam's government collapsed on30 April 1975. The DMZ ceased to exist after the reunification of the two Vietnamese countries under communist regimes: First theRepublic of South Vietnam (de facto controlled by the Viet Cong and the North) and the Democratic Republic of Vietnam, then full reunification as the communistSocialist Republic of Vietnam on 2 July 1976.
