Who is Thomas Stansfield from Transfer of Power and what is their importance?

Thomas Stansfield is the director of the CIA. He is known for being notoriously difficult to read and experienced in espionage. Described as wise and intuitive, Stansfield trusts Dr. Kennedy implicitly. and is not afraid to make enemies of even the most powerful Washington politicians. Stansfield lives outside of the chain of command and breaks rules when necessary.