This anniversary also recalls that during the Cold War American spies, such as Julius and Ethel Rosenberg, stole atomic secrets and sent them to Moscow.

FORBES: Fact and Comment

Withholding Smiley's voice is one of many intriguing games that the film plays in the course of a Cold War mystery about spies playing sinister games of treason and personal betrayal.

WSJ: Young Adult | Tinker Tailor Soldier Spy | Nervy 'Young Adult' Dazzles by the Book | Film Review by Joe Morgenstern

With the end of the cold war, some professional spies offered their talents to business.

BBC: I spy with my private eye.....