Vance served as senior adviser to the secretary of state, coordinator for international narcotics matters, and executive director of the President's Cabinet Committee on International Narcotics Control (1974–1977).
Vance held key roles in the U.S. government, including serving as a senior adviser to the secretary of state and overseeing international narcotics matters. He was also the executive director of the President's Cabinet Committee on International Narcotics Control during this period.