Nguyễn Khánh
In April 1960, Quát signed the Caravelle Manifesto, a list of grievances and demands specifically critical of Diệm, and was promptly jailed by the GVN. After Diệm's assassination in October 1963, Quát was appointed Foreign Minister by Major General Nguyễn Khánh, one of the principal participants in the bloody coup. Though Quát frequently criticized Khánh's self-serving rule, he remained in Khánh's cabinet until November 1964, when Trần Văn Hương was installed as Prime Minister of General Khánh's freshly created High National Council (HNC).