And if that tickles your fancy, "Tinker Tailor Soldier Spy" [0] is an excellent miniseries from 1979 about a mole in MI6, perhaps the best spy series ever made. I didn't care about the movie much, so don't let this deter you, but Alec Guiness as George Smiley is a perfect match. John Le Carré thought so, too.

Oh and Patrick Steward plays "Karla" the soviet mastermind in this series and its successor "Smiley's People". Just a few seconds, but very memorable, its incredible really.

[0] https://www.imdb.com/title/tt0080297/