The gravel drive leading up to Christiane Kubrick’s mansion near St Albans in Hertfordshire is protected by three sets of electronic gates and “Strictly Private” signs that must put the fear of God into the paper boy.

Inside the front door of Childwickbury House there are more printed orders to the effect of: “Shut and bolt this door at all costs.” Christiane clings to her privacy like a hot-water bottle.

It’s a rare honour to be invited into her vast, tiled kitchen with its views of white iron fences and lush green pastures. It is even rarer to stroll through the glass-roofed courtyard littered with paintings, past the creepy feathery masks for Eyes Wide Shut, and into a blood-red library crammed with art books, Thackeray, De Sade and the well-thumbed volumes on witchcraft that Stanley Kubrick collected for The Shining.

Unfortunately, his widow can’t stroll anywhere at the moment. In August a collision with one of her dogs shattered the 74-year-old’s right leg in five places. To negotiate the three steps leading from the kitchen she has to clamber off a wheelchair and inch herself across a floor which, when I meet her, has just been washed. The German-born artist refuses to be helped by her wary assistants, and thus leaves a damp mark on the seat of her chic dress.

She married Stanley in 1957, and the couple settled into this quirky house and splendid isolation in 1979. Christiane admits that she doesn’t much enjoy the attention of strangers, particularly journalists, but she feels a duty towards her husband’s extraordinary legacy, if only to spike the popular misconceptions that still haunt his biographies.

It feels strange to grill Christiane about Stanley. But a newly restored print of the American director’s masterpiece, Dr Strangelove: or, How I Learned to Stop Worrying and Love the Bomb, is one of the centrepieces of the 50th Times BFI London Film Festival, and the opportunity to discuss the movie at Fort Kubrick with a woman who lived with him for 42 years is not to be dismissed lightly. Christiane will not be drawn on which of Stanley’s films she admires most, but she does acknowledge how “hideously pertinent” Dr Strangelove is now. This terrifying black and white satire, starring Peter Sellers, Sterling Hayden and George C. Scott, is a cynical vision of weapons technology and human stupidity in which the world comes to an end thanks to an American general’s paranoia about women and communists.

“Dr Strangelove is not only a documentary, but an extremely innocent one given today’s possibilities,” says Christiane. “There are so many more things that can go wrong. Weapons are a hundredfold more dangerous. Giant mistakes are easier to make. We don’t have the mental tools to make critical split-second decisions.

“I remember when Peter George’s book Red Alert came out around the time of the Cuban missile crisis [in 1962]. Stanley said: ‘We’re not anywhere near scared enough.’ He thought we were being as blinkered as the Germans under Hitler. He even bought tickets to Australia.

“Then he called Terry Southern [the screenwriter who was to work with Kubrick on Dr Strangelove, their adaptation of Red Alert] and they rolled around the floor in hysterics reading out loud the things that could happen. Stanley decided he had to shoot it as a comedy because you simply couldn’t swallow it straight.”

What’s interesting is that Kubrick didn’t think that his films might make the slightest bit of difference. “He was never that naive,” says Christiane. “He couldn’t make a film unless he fell in love with the story. Then he couldn’t wait to get it on screen. But it had to be just perfect, which is why he left long gaps between films. If he didn’t have an absolute crush on a story he said: ‘I won’t survive the filming. I’ll get bored.’

“He abandoned many projects — sometimes after one or two years — because he suddenly ran out of excitement. He hated himself for doing so but, like a poker player, you can’t play a bad hand simply because other people are winning.”

As Kubrick grew older, good stories became harder to find. “He did get more self-critical,” says Christiane, “and, as we all do, more jaded. He also had some bad luck. He couldn’t get the finance to do Napoleon, and the film he wanted to make around 1993 about the Holocaust [based on an adaptation of Louis Begley’s novel, Wartime Lies] he gave up because he couldn’t stand it any more.

“It was far too dark. The SS papers were too much to bear. Stanley would lie in bed all day after researching this stuff because he didn’t think it was worth getting up. It’s the only film I persuaded him to leave alone.

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