 The December 1964 South Vietnamese coup took place before dawn on December 19 , 1964 , when the ruling military junta of South Vietnam led by General Nguyễn Khánh dissolved the High National Council ( HNC ) and arrested some of its members . The HNC was an <unk> legislative @-@ style civilian advisory body they had created at the request of the United States — South Vietnam 's main sponsor — to give a veneer of civilian rule . The dissolution dismayed the Americans , particularly the ambassador , Maxwell D. Taylor , who engaged in an angry war of words with various generals including Khánh and threatened aid cuts . They were unable to do anything about the fait <unk> that had been handed to them , because they strongly desired to win the Vietnam War and needed to support the Army of the Republic of Vietnam . Instead , Taylor 's searing verbal attacks were counterproductive as they galvanized the Vietnamese officers around the embattled Khánh . At the time , Khánh 's leadership was under threat from his fellow generals , as well as Taylor , who had fallen out with him and was seeking his removal . 
