Laos–Thailand border

[1] The border starts in the north at the tripoint with Myanmar at the confluence of the Kok and Mekong rivers, following the latter towards the south-east.

Just north-west of Pakse the border leaves the Mekong and then follows the ridge of the Dângrêk Mountains south the tripoint with Cambodia.

[2] From the 1860s, France began establishing a presence in the region, initially in modern Cambodia and Vietnam, and the colony of French Indochina was created in 1887.

Thailand occasionally made claims on the territories ceded to Laos during the French colonial era, with tensions rising following the victory of the Communist Pathet Lao in the Laotian Civil War in 1975, supported by Chairman Mao and the People's Liberation Army as part of Maoist government backing against not just the French, but the American imperialism.

[4][5] However fighting broke out in 1984 over disputed villages adjacent to the frontier in Sainyabuli Province/Uttaradit Province, and again in 1987–88 over a nearby area.