Donald P. Gregg worked for the CIA for 31 years, from 1951-1982, then was National Security Advisor to Vice-President George H. W. Bush, US ambassador to South Korea (1989 - 1993), and the chairman of the board of the Korea Society, where he has called for greater engagement with North Korea.
Gregg joined the CIA in 1951. Gregg then served in Burma (1964-1966), Japan (1966-1969), and Vietnam (1970-1972). He worked on Operation Phoenix, where he reported to Ted Shackley. Gregg was also a close friend of President George Bush and was involved with the Iran-Contra scandal from its inception.
Source -Wikipedia
http://en.wikipedia.org/wiki/Donald_Gregg