Film:
* The Godfather Part III (1990) - Don Altobello
* The Jewel of the Nile (1985) - Omar
* The Last Emperor (1987) - Italian Ambassador
* The Right Stuff (1983) - John Glenn (voice)
* The Ten Commandments (1956) - (uncredited)
Television:
* The Crown (2016) - Lord Mountbatten
* The West Wing (2000-2006) - Vice President John Hoynes
* The Man in the High Castle (2015-2019) - Heinrich Himmler
* Murder, She Wrote (1984-1996) - Various roles
* Babylon 5 (1993-1998) - Ambassador Sheridan
* Star Trek: Deep Space Nine (1993-1999) - Ambassador Leyton
* Quantum Leap (1989-1993) - Various roles
* The Twilight Zone (1985-1989) - Various roles
* The Adventures of Brisco County, Jr. (1993-1994) - Various roles
Other Projects:
* The Complete History of America (1989) - Narrator
* The Vietnam War (2017) - Narrator
This is not an exhaustive list, but it highlights some of his most memorable and prominent roles. He is a versatile and experienced actor, and his contributions to the entertainment industry are significant.