The Vietnamese Demilitarized Zone was a demilitarized zone at the 17th parallel in Quang Tri province that was established as the dividing line between the two countries i.e. North Vietnam and South Vietnam from 22 July 1954 to 2 July 1976 when Vietnam was officially divided into the two military gathering areas, which was intended to be sustained in the short term after the First Indochina War. Wikipedia