Pathet Lao was a political and communist movement in Laos that was established in the mid-20th century. The organization eventually succeeded in gaining the highest power in Laos after an internal war. war or revolution (against the French and American) that lasted from the 1950s to 1975. The organization had very close relationship with the Vietnamese communists. During the Indochina War, the organization was effectively organized, supported and equipped by the Democratic Republic of Vietnam.