[2] Annexed in 1941, Thailand returned it to French Indochina in 1946, along with all other areas it had gained by the war as a condition for admission to the United Nations.

Accordingly, all wartime claims against Thailand were dropped and the kingdom received a substantial American aid package in gratitude for the assistance its anti-Japanese underground had provided to the Allied war effort.

In August 1940, after a series of border clashes, the Axis-leaning government of Thailand attacked French military posts on the eastern banks of the Mekong between Vientiane and Champassak Province.

[3] The Thai administration was not very active in the province during that time and the largely rural districts were pretty much left to themselves until they were reincorporated into Laos.

[4] At the end of World War II France threatened to block Thai entry into the United Nations unless it returned the provinces to their colonial empire.