Pieczenik was
Deputy Assistant Secretary of State under Henry Kissinger, Cyrus Vance and James Baker. He served the presidential administrations of Gerald Ford, Jimmy Carter, Ronald Reagan and George H. W. Bush in the capacity of deputy assistant secretary.
In 1974, Pieczenik joined the United States Department of State as a consultant to help in the restructuring of its Office for the Prevention of Terrorism. In 1976, Pieczenik was made
Deputy Assistant Secretary of State for management.
At the Department of State, he served as a "specialist on hostage taking". He has been
credited with devising successful negotiating strategies and tactics used in several high-profile hostage situations, including the 1976 TWA Flight 355 hostage situation and the 1977 kidnapping of the son of Cyprus' president.