Southeast Asia Treaty Organization (SEATO), alliance organized (1954) under the Southeast Asia Collective Defense Treaty by representatives of Australia, France, Great Britain, New Zealand, Pakistan, the Philippines, Thailand, and the United States. Established under Western auspices after the French withdrawal from Indochina, SEATO was created to oppose further Communist gains in Southeast Asia. The treaty was supplemented by a Pacific Charter, affirming the rights of Asian and Pacific peoples to equality and self-determination and setting forth goals of economic, social, and cultural cooperation between the member countries. The civil and military organizations established under the treaty had their headquarters in Bangkok, Thailand. SEATO relied on the military forces of member nations and joint maneuvers were held annually. SEATO's principal role was to sanction the U.S. presence in Vietnam, although France and Pakistan withheld support. Unable to intervene in Laos or Vietnam due to its rule of unanimity, the future of the organization was in doubt by 1973, and SEATO was ultimately disbanded in 1977.