George Shulz served in various positions under three U.S. presidents -- in fact Shultz held four different cabinet-level posts over the years.

An economist by training,  Shultz came to Washington as Richard Nixon's first Labor Secretary.  He became Director of the Office of Management and Budget a year later, and a year after that Nixon appointed him Treasury Secretary.

Ronald Reagan was elected president in 1980. and in 1982 chose Shultz as his Secretary of State. Shultz became a key shaper of foreign policy during  the Reagan's administration. 

I met him in the spring of 1993, when he wrote a long memoir of his years at the State Department.

So here now, from 1993, George Shultz.