Laos–Vietnam border
The Laos–Vietnam border is the line between Laos and Vietnam. It is about 2,161 kilometers (1,343 miles) long, from the China border in the north to the Cambodia border in the south. The border mostly runs southeast, then briefly west along the Nam Sam River, and then southeast again along the Annamite Mountains and the Sepon River to the Cambodian tripoint.
Historically, the Annamite Range was a natural divide between Vietnamese lands and Lao, Thai, and Khmer kingdoms. In the colonial era, France created French Indochina, which included Laos and Vietnam. Laos was part of Siam (Thailand) until 1893, when it joined French Indochina. The exact border line was not fixed at first; later demarcations in 1916 and colonial maps shaped the frontier.
Laos gained partial independence in 1949, Cambodia in 1953, and Vietnam in 1954 (though Vietnam was split into North and South with a demilitarized zone). The border area became a route for wartime supply lines, including the Ho Chi Minh Trail, and was heavily bombed during the Vietnam War.
After the region came under communist control in the 1970s, a border treaty in 1976 set the frontier along the colonial line. Cambodia later faced the Khmer Rouge regime, which Vietnam helped to end in 1979. From 1979 to 1984, the border was demarcated on the ground, with minor changes in 1986. Today there are several border crossings between Laos and Vietnam.
This page was last edited on 3 February 2026, at 01:52 (CET).