Introduction This chapter deals with the question of how the Cold War influenced the development of democratization in Thailand, and focuses on the period of the Vietnam War. Democratization is defined here as a long-term political process by which a social structure grows more stratified and new social forces emerge to participate in political arrangements.1 The system reaches full-fledged ‘democracy’ when the lower strata perceive that it is in their interests to participate. The process may be uneven; at certain points the system appears close to achieving democracy only to be interrupted by concerted attempts to reduce participation.2 The chapter argues that the United States played an active role both in the uneven development of Thai democracy and in the events leading up to the violence of 1973. Particularly during the Indochinese wars, the USA needed a stable Thai government prepared to enter into friendly relations, and was prepared to go to great lengths to secure these objectives.