Broadcaster Jon Ronson has made a name for himself by writing about marginalised people. By meeting and interviewing various cranks, eccentrics, delusional maniacs, dictators, messianic cult leaders, hobbyists and a lot of other people who 'mainstream' journalists tend to pass over, he sometimes lands himself with fascinating source material for newspaper articles, books and documentaries.

His success in these endeavours seems to hinge on his self-deprecating charm and his enthusiasm for chasing a story, no matter how unhinged it might sound. One of his earlier books Them: Adventures With Extremists featured a motley cast including Omar Bakri Muhammad, David Icke, Dr Ian Paisley and various objectionable despots, conspiracy theorists and political bullies.

Significantly, Ronson has a genuine love for research and storytelling, something that becomes clear when you observe how one project sparks off another and then another. This is one of several things that puts distance between him and other slightly more dispassionate journalists such as Louis Theroux.

While meeting with the 'psychic' spoon bender Uri Geller in order to plan a trip to find the Last Arc Of The Covenant in Iraq, Ronson first became aware of rumours of a secret network of psychic spies in the employ of the CIA. This eventually became the basis of a TV series and book called The Men Who Stare At Goats. The book documents the seemingly insane proposition that during the 80s there was a secret 'New Age' psy-ops unit in the American Army called The First Earth Battalion who believed in such things as being able to walk through walls. As his investigation continued it became clear that these barmy but essentially well-meaning theories had become bent out of all recognition and had been applied as exotic interrogation and torture techniques in Abu Ghraib and Guantanamo Bay.

The book — or at least the madcap, comic bits of it — has been made into a Hollywood movie starring George Clooney, Jeff Bridges and Kevin Spacey. We caught up with Jon to see what he thought of the film and how the project got underway.

(Fans of Ronson will be pleased to know that he was exactly as you'd expect him, i.e. funny and charming, while using up a third of the interview time fretting about his son's asthma and swine flu.)

When I read The Men Who Stare At Goats a few years ago I thought it would have fallen into the same category as Ulysses or The Little Book Of Calm, you know — an unfilmable book.

Jon Ronson: [laughs] Well actually when I was writing it I did think it would be filmable if someone who had powers that I didn't have, knew how to do it. I thought my previous book Them is much more unfilmable but then it has been bought by Universal and Mike White, so maybe that will work as well. I think with both books there's enough there to make them work. I guess there was a weird structural reason for making me think that it would make a good book and that was that all these people knew each other. The main players were in this small 80s paranormal community and that made it easier to write the book. And I sort of think that makes the film easier too. So my crap answer to your good question is that it would be easy to make it into a film if it were fictionalised in a certain way. And I think that's what [screenwriter] Peter Straughan did.

He added more of a narrative arc to your journalistic book?

JR: Yeah, more of a story. Well, you know how the book starts with General Stubblebine trying to walk through the wall? Well, when I wrote that I definitely thought that could be the opening scene of a movie. Him trying to walk through his wall because most matter is made up of space. That scene definitely felt like the opening of a Catch-22-style movie to me.

So is there any sense in which Ewan McGregor is playing you?

JR: Sort of but to a lesser extent than some of the other actors are playing real people. For example Jeff Bridges is totally playing a real-life guy called Jim Shannon but in the film he's called Bill Django who was a Lt. Colonel who . . . started the madness. George Clooney is playing an amalgamation of a few very definite and recognisable people. Ewan is sort of playing me but he's not as nebbish-y, auld and tiny like I am but he's still playing someone who is smaller than one of the military people.

That's quite good, that, I'd be happy with Ewan McGregor playing me. Does he manage to keep his penis covered up in this movie?

JR: Yeah he does. Which is funny because while I was writing it I was forever showing people my penis! I'd be asking someone a question about goats and then . . . 'Here it is!' You do see his arse.

You do? The boy can't help himself.

JR: In fairness to Ewan it was in the story.

Are you saying he only did it because the script was tasteful and called for his nudity?

JR: [laughs] Him and George Clooney get injured and they end up wearing those medical smocks where you can see the arse.

When did you first hear about all this psy-ops stuff that forms the backbone of the book and was it linked to research you'd done on an earlier story?

JR: Sort of. The first inkling of it was from Uri Geller. I'd met him about 15 years ago because he said he knew where the Arc Of The Covenant was buried in Iraq and that he was going to dig it up. So I thought that sounded like a good journey. He said 'come to my house to discuss the logistics of the trip.' I got to his village an hour early and just as I arrived my phone rang and it was Uri Geller. He said 'Before you set off, do you mind picking something up on the way?' And I said 'Well it's funny you should say that because I'm just round the corner.' And he said: 'I knew it! I could feel your presence in the village!' And he was like that all day. So if he was given the chance to claim psychic power over something that I had just done, he did. He gave me a tour of the house and he said stuff like 'This is my Jewish prayer shawl. The thing about the Jews, Jon, is . . .' And I said 'You don't need to tell me, I'm Jewish.' And he said 'I KNEW IT! I knew the next person who came into this room would be Jewish!' Anyway, he told me that he was once part of a secret spying unit and that he'd been working for the CIA and then just after 9/11 I just got it into my head about this secret psychic spy stuff so I phoned him up and offered to buy him lunch. He turned up with his brother-in-law and I said 'Tell me about your career in secret spying' and he said, 'I never talk about it.' I said 'What are you talking about? You've told Woman's Own, you've told The Scottish Daily Record . . .' He said 'Alright but if you repeat what I tell you I will deny it. I have been reactivated.' And that was my first hint that either Uri was completely mad or that post 9-11 the CIA had phoned him up and asked him if he had been having psychic visions. And I thought that was interesting enough to be a journey to find out whether Uri was telling the truth or not. And on the way I found this weird, submerged story about killing goats by staring at them and so on.

But did you find that this story which ostensibly had very comic overtones, the more you looked at it, the darker it got?

JR: Absolutely. The first half of the book is funny and slapstick. I met this guy called Glenn Wheaton — the George Clooney guy from the movie — who was telling me about Project Jedi. It was all based on levels. Level one meant you would eat nuts and grains for a month. Then level two was invisibility. There was kind of a big leap from level one to level two. Back then it was going to be a funny comic story about these madcap people but when I was writing the book Abu Ghraib happened and a lot of the people who had been involved in these mad goat-staring ideas in the 80s started to say that some of the ideas that were being reported on in Abu Ghraib and Guantanamo Bay — these ways of freaking people out and interrogating people in exotic ways came from the same well of ideas that all the paranormal stuff came from. So yeah, halfway through the book it does take this kind of dark turn into torture and esoteric interrogation ideas. The film doesn't really do that; the film stays funny the whole way through. I presume that they thought that that kind of lurch from one kind of a genre to another can work in a book but not really in film.

It's quite sad really because in a weird sort of way, the original ideas of new age warfare — people taking lambs on to the battlefield and stuff like that . . . well, they had their hearts in the right place really didn't they?

JR: Yeah. In the middle of all this, there's a nice story about the military that they're willing to journey to the furthest corners of their imaginations without embarrassment to try things out. And especially in trying out things that are non-lethal. The sparkly eyes technique and so on. These rather sweet techniques of warfare. So when this was bent into different ways of torturing people years later — that's not the fault of the people who came up with these ideas.

I guess that's the problem with most new inventions, philosophies, scientific breakthroughs etc — they can be put to ill use by the wrong people.

JR: Maybe when psychopaths take over or maybe it's just human nature. I'm not sure what I think about the whole Stanford Prison Experiment — that we're all capable of great evil. I've got a feeling that I'm not capable of great evil.

I've got a feeling that I'm capable of mediocre evil. A mid-range nastiness to animals and small children. Did you have any part in the filming? Did you meet any of the people involved?

JR: Yeah, I've met them all. I was involved but not in any kind of creative way and rightly so. I didn't particularly want to be involved nor do I think I should have been. You hear stories about authors interfering and it ending in tears . . . It's kind of like a relay race so when you pass the baton to someone else you don't go chasing it to get it back. So I decided right from the beginning that I wouldn't interfere and I didn't. But I wanted to experience what it was like on the set so me and Peter who wrote the screenplay went off to Portugal to watch some of it be filmed. After the film got finished we all met again at the Venice Film Festival and then again at Toronto and again in London. So I've got to know them all quite well, especially George Clooney.

Well, I can guess what the answer's going to be but: do you like it as a film?

JR: Yeah, very much so. You can only go by what your very first feeling of it is. And it was a viewing that they had for Kevin Spacey. And within two minutes of the film starting there's this scene where this hamster falls over and you just sort of think it's a really funny, sweet, warm film. In some ways it's similar to the book because it's got those elements that the book's got but it doesn't have the darkness. There's something really engaging about it. A lot of it is down to George Clooney and a lot of it is down to Peter's script. There's just something batty and sweet natured about it.

How does it compare to something really violent and exciting like Predator II?

JR: [laughs] I'll tell you what the film's like. When I watched it for the first time the film that it reminded me of the most was Little Miss Sunshine. It's like Little Miss Sunshine but with war. Not everyone's going to love it but a lot of people seem to. What I was doing right at the beginning, which I've had to stop because it's totally insane, is knowing when there's a screening and going on to Twitter and seeing what people are Tweeting about it. I've stopped doing that because not only is it completely insane it's completely masturbatory. I think the people who like it, like it in the way that they would like Little Miss Sunshine. It's small and good natured.

You've spent a lot of time with Robbie Williams; what do you make of his new single and album?

JR: I've got no aesthetic judgement whatsoever. I mean, I liked Rudebox I thought it was great. I don't want to come across as too luvvie-ish but I really like Robbie and it's really nice to see him doing well again and being happy again. I've only heard 'Bodies' and one or two other tracks but yeah, really good.

And what's the screenplay that you're working on with Peter?

JR: It's called Frank and it's about the music industry. And I think it's good. It took us a long time, especially me. I'd be beavering away on it for ages. Peter, because he's a pro, would do his bit in two weeks! But we've finished the first draft.

So what's the elevator pitch?

JR: It's like about mediocrity and originality. It's loosely based on the story of my time in Frank Sidebottom's Oh Blimey Big Band but we've kind of turned it into a weird dark comedy about jealousy and mediocrity and how it's hard to be with someone who is far more talented than you and how it will drive you crazy.

The Men Who Stare At Goats is on general release now. Check the Quietus later in the week for more Goat action.