Most movie-goers do not know the story behind the acclaimed new film Tinker Tailor Soldier Spy, opening nationally this weekend.  Adapted from the 1974 John Le Carré book, and the 1982 sequel Smiley's People, both were dramatized on BBC TV and PBS and can be found on Netflix and other sites.

Le Carré, the pen name for David Cornwell -- who served in MI6, Britain's secret intelligence service -- penned the two books (and the Honorable School Boy, the third installment in this trilogy), drawing on the real-life drama that tore apart the British spy demi-monde in the 1950s, '60s, and '70s: the discovery that the Soviet KGB had recruited upper-class British subjects to penetrate U.K. intelligence agencies.

Their infamous careers as spies are legends in Europe, but not as well-known in the U.S., which says volumes about the American culture.  Yet three of the five penetrated U.S. secret services and diplomatic departments, setting off one of the most dramatic spy-hunts in U.S. history by James Angleton, the chief of counterintelligence for the CIA.  The manic hunt for a mysterious additional hidden Soviet spy in the CIA was considered the most damaging episode in the spy agency's history by former director William Colby.

The KGB called them the Magnificent Five for their great successes, after the film The Magnificent Seven.  But history remembers them as the Cambridge Spies since they were recruited by the KGB while students at the university in the late 1930s and early 1940s.  In 1951, two of the moles -- Donald McLean and Guy* Burgess -- fled to Moscow after a tip stating that the secret service was hot on their heels.

In 1963, the suave and debonair Kim Philby, considered the ringleader -- and responsible for transferring U.S. atomic secrets to his handlers while posted as a liaison to Washington -- showed up in Moscow and held a press conference in a KGB colonel's uniform.  His defection was an international sensation, but MI5 and MI6 knew that there were two more moles.  In 1978, Anthony Blunt -- Surveyor of the Queen's Pictures and director of the Courtauld Gallery -- was exposed as the Fourth Man.

Through the 1980s, conspiracy theorists  and alleged intelligence experts speculated on the identity of the Fifth Man.  The book Spycatcher, written by retired MI5 senior officer Peter Wright in 1985, accused the former director of MI5 Roger Hollis of being the Fifth Man.  The book was banned in the U.K. but published in Australia, and it remained on the New York Times bestseller list for 8 months.

In 1990, Cambridge intelligence expert Chris Andrew published KGB: The Inside Story in collaboration with KGB colonel and double-agent Oleg Gordeivsky, who had access secret files in Moscow.  The Fifth Man turned out to be John Cairncross from Glasgow, who was living the good life in the South of France when exposed.  Neither he nor Blunt was formally charged, but the mystery of the Fifth Man was settled, even though conspiracy theorists continue to maintain that Hollis, even if he was not the Fifth Man, was indeed a Soviet spy who had penetrated the top post in MI5.

Le Carré believed that the Cambridge Moles chief Kim Philby worked behind the scenes to have him terminated from MI6.  Yet the author maintains a moral ambivalence concerning who was right and who was wrong during the long Cold War between the USSR and its captive satellites and the U.S. and the West.  He is openly anti-American and continues to publish with a decided leftist slant.  But no matter.  Tinker Tailor Soldier Spy is an intellectually fascinating glimpse into the U.K. spy culture that continues to interest readers worldwide.  Think James Bond in a drawing room.

Formed in 1909, the U.K. secret intelligence services were the first in the West to elevate intelligence operations to a high level in both war and peace.  The U.S. shunned spy activity ("gentlemen don't read other gentlemen's mail," said Henry Stimson) until World War 2, when the Office of Strategic Services (OSS) was created under the direction of attorney William Donavan, who garnered the nickname "Wild Bill" for his exploits around the world.  Donavan was dismissed and his OSS disbanded by President Harry Truman in 1945.  (Douglas Waller's book Wild Bill Donavan is the latest and best work on Donavan.)

Yet Truman knew that America's naïve attitude about espionage was outdated in the postwar world.  In 1947 the Central Intelligence Agency was established to counter  threats to national security, with the president in charge to counter the Soviets who occupied Eastern Europe and later erected the infamous Berlin Wall in 1961.

The OSS laid the groundwork for CIA, using the British model that eventually separated internal security from global operations.  Several sections operated under the umbrella term Military Intelligence.  MI5 evolved into the "security service" mandated to work within the U.K.  MI6 was created to maintain British security interests worldwide.  (There were as many as 9 MI departments at one time).

But there was one glaring exception to the U.S. version of the British template: FBI director J. Edgar Hoover would not tolerate a separate espionage internal security service along the lines of MI5.  The CIA operates outside the U.S. (with some exceptions) like MI6, but the FBI took charge of domestic security operations -- with mixed results

The difference from MI5 centers on the FBI's original law and order mandate.  The core goal is to identify, arrest, and go to court.  For MI5, the idea is to watch and wait and rarely frighten the horses with a public trial.  Not until the early 2000s did the FBI shed its drug enforcement duties to free up resources to focus firmly on national security threats caused by terrorist activities.

And the FBI has made a serious mistakes in altering its mission due to its old habits as cops catching robbers, including missing surveillance of the 9-11 suspects before they struck.  In another bad moment for the Agency, they  mistook CIA officer Brian Kelley for one of their own -- the notorious high-ranking FBI agent Robert Hanssen, who worked as an agent for the Soviets, and afterward for the Russia Federation.  The film Breach picks up the story after Kelley was cleared and the Agency realized that they had a serious problem.

Le Carré's guided tour into the murky world of British espionage depicts a clubby yet lethal subculture that does not need chase scenes, pyrotechnics, and beautiful girls to keep audiences engaged.  Simply digesting the nomenclature requires attention, such as "cousins" for the CIA, honey-traps to lure agents with sex, Romeos and Swallows for operatives who use seduction to gain secret information, scalp-hunters for assassins, babysitters for bodyguards, ferrets for special agents who gain entry to plant eavesdropping equipment, and pavement artists for surveillance teams.

It's great stuff -- and it's true.

*corrected

Bernie Reeves is editor & publisher, Raleigh Metro Magazine, and founder, Raleigh Spy Conference.