The movie brilliantly conjures up the heavy weather of Le Carré's spy game: it involves nothing like derring-do, but a ritual of humiliation and a ballet of shame in which the security services play their part in managing decline and managing denial, and the Brit spooks try to rebuild their reputation with the Americans – the only people with secrets worth keeping – in their calamitous post-Philby world. While we are still living in a Britain ruled by public school elites, this aristocratic concept of service would appear long gone. The film received numerous Academy Award nominations, including a nomination for Best Actor for Gary Oldman for his role as George Smiley.

Karla is nominally an unseen character who operates either through functionaries, hitmen, or by turning his enemies into double agents. Once a Cambridge don, he becomes convinced that one of his subordinates is a Soviet agent, and spends the last years of his tenure trying to uncover them. Smiley then visits Max, a Czech operative who served as a legman for Jim on the operation, who tells Smiley that Prideaux gave him instructions to leave Czechoslovakia any way he could if Jim didn't surface at the rendezvous at the appointed time.The director cast Gary Oldman in the role of George Smiley, and described the actor as having "a great face" and "the quiet intensity and intelligence that's needed".

I said: ‘It’s not about the size of George Smiley’s tummy; it’s about the size of his massive brain, for heaven’s sake. Guillam begins to suspect that the operation is being undermined by their nominal allies in the CIA, in cooperation with certain elements of the British government. He tells him that Karla regarded Smiley as the person most likely to uncover Haydon and that the affair was calculated to cloud Smiley's judgement and cast any accusations he may make as the vengeance of a wronged husband. Melvyn Bragg wrote that le Carré sought to illustrate that "the public or institutional default is always more excusable than the personal betrayal of faith.

Recruited by Smiley at Oxford, he was the top specialist in Soviet satellite states and spent several years undercover as a left-wing academic in the Balkans before being instated in the Circus. When Smiley confronts Esterhase about Operation Witchcraft, he states that Esterhase was a "wanted man" at the time of his recruitment and implies that Esterhase is still a fugitive.