"We were shown 16mm 'educational' films about what to do when you see the white flash, even giving us false hope that if we did see the white flash, if we followed the instructions, it was survivable," he said, "which I didn't believe for a second."
Bridge of Spies fully evokes those anxieties while serving up a bedrock of a leading character in Donovan, embodied by Hanks as the soul of decency and democratic values. The lawyer was a former general counsel for the Office of Strategic Services and an assistant to the prosecution during the Nuremberg trials. He was working at a New York law firm when he was asked to represent Abel in his spy trial, and successfully argued against the death penalty.
Although Donovan won praise from Supreme Court Chief Justice Earl Warren for his determination, the lawyer received death threats, and his home was sprayed with gunfire. After Powers was captured, a plan was hatched to offer Abel in trade. Because of his relationship with the agent and sharp negotiating skills, Donovan was asked to participate in the covert operation to set up the trade.
"The art of the negotiation was something he took to heart," said Spielberg. "The whole movie is about conversation and the positive results conversation can have. In that sense it's an anti-war film."
Much of the movie is driven by dialogue scenes between Donovan, a man who increasingly must rely on nerve and instinct, and another character - whether that involves intimate discussions with the poker-faced Abel (Mark Rylance), the double-talking East German and Soviet officials with whom Donovan barters, or his wife (Amy Ryan), who fears for the safety of her husband and family.
Though impressed by Charman's screenplay, Spielberg brought in the Coen Brothers (Fargo, No Country for Old Men) for rewrites; their efforts punched up the language and sharpened the characters. They uncovered new facets in the story, including the phony family the Soviets invented for Abel to greet Donovan in East Berlin as he arrives to feel out the situation. The comic strokes undercut the tension the film expertly builds, but they aren't isolated - an element that sets Bridge of Spies apart from the dour tone of classic Cold War movies.
History buff that he is, Spielberg realised that he couldn't make the same kind of movie he admired, such as The Spy Who Came in From the Cold. For one thing, the plot machinations often were inscrutable. "I wanted to make sure the movie wasn't too esoteric for the sake of capturing a style that Hollywood has stamped," said the director, who nonetheless pays homage to Martin Ritt's 1965 adaptation of the John Le Carre thriller, with the glimpse of a fatal attempt to escape over the newly built Berlin Wall.
"I didn't need this film to be elliptical. You don't need to feel like you're navigating yourself through the maze at the end of The Shining."
With Hanks, and his portrayal of Donovan, he also had a central figure who has no moral ambiguity, unlike archetypal Cold War characters, who seemed as divided as Berlin after the wall had been built. Though stressed by his responsibility to his family, Donovan is otherwise dead certain in his purpose. That didn't mean, Spielberg contended, that Hanks is just playing Hanks.
"It's about his subtlety and what he gives me on every take," said the director, who has worked with the actor in three previous films, including Catch Me If You Can and The Terminal. "He doesn't just figure out what to do on take one and punch cards with six or seven identical performances. He introduces ideas through his words and physical actions."
Spielberg, who can count 28 theatrical films as a director, likewise takes nothing for granted.
"A lot of ideas seemed to have been thought out, but when inspiration strikes him on set, there he is lying on the ground, looking through the camera, trying to figure what the angle is," Ryan said. "You get an idea of what Steven was like as an 8-year-old boy in his back yard."
In its ambition to re-create such a time, Bridge of Spies indulges the fantasy of Hollywood as the ultimate way-back machine. Spielberg enlisted production designer Adam Stockhausen to re-create the look of the period, whose locations range from sunny, tree-lined Brooklyn to the chilly interiors of the Soviet embassy, with cars and garments to match.
"I like seeing men in hats," Spielberg said. "It was still the era of the fedora and the bowler. It was an interesting confluence of the passing of one era into a much more progressive era of American history."
As it happened, Spielberg's father, an engineer for General Electric, was the first to document it for him. He went to Moscow in 1960 as part of a cultural exchange programme. The U-2 incident was very fresh, and the Soviets had quickly set up an exhibit with the wreckage. "A Russian officer somehow knew that my father and the others were American," Spielberg said. They were yanked to the front of the line, passports briefly seized, as a Soviet colonel barked at the Americans: "Look at what your country is doing to us!"
The visiting engineers managed a safe return home. And the young Spielberg watched his father's Super-8 films of the experience: "It was tattooed on my brain."
Lowdown
What: Steven Spielberg directs Bridge of Spies
Who: Starring Tom Hanks and Alan Alda
When: In cinemas now