Patrick West

Colonel Patrick West was a Starfleet officer who was involved in a conspiracy to sabotage peace-making efforts between the Klingon Empire and the United Federation of Planets. He first appeared as a proponent of invading Rura Penthe to rescue Kirk and McCoy, and later, disguised as a Klingon, attempted to assassinate the Federation president. He was killed by Montgomery Scott and later unmasked.

Comments

• Note that "Colonel" is not a Starfleet rank (they use the modern U.S. Navy ranks), suggesting that he might be part of a non-Starfleet branch of Federation military.
• West is omitted from J.M. Dillard's novelization of The Undiscovered Country. He is replaced in the briefing scene in the president's office by "a young lieutenant," and at the end by an anonymous Klingon assassin (who in Dillard's novel really is a Klingon and not a disguised human).