BBC Four: What attracted you to this story?
Ben Lewis: It was an accident. The BBC asked me to make a film about the Rainbow Warrior or Greenpeace's anti-nuclear missions. I said no because I thought it was just a load of hippies getting wet. By that point I had sort of 'stumbled across' this story of how the French had spent 30 years testing nuclear bombs in Tahiti. The Americans and Brits both tested bombs in the South Pacific but they hadn't spent 30 years doing it. They hadn't turned a local population into nuclear navvies - a dependent colony providing a nuclear work force. So I went back to the BBC and said that here was a story about French nuclear testing. There had been a film about the British bomb and films about the American bomb, famously Radio Bikini, and I wanted to make the French one. I felt that this was an archetypal Paradise Lost story. There have been millions of them, but this is probably the only one connected to nuclear bombs. I thought I was telling an age-old mythand a real-life story.

BBC Four: Was it difficult to get access to both sides of the argument?
BL: It was very difficult to get the cooperation of the French Ministry of Defence, because they are clearly a well-meaning, but rather incompetent, slow-witted bureaucracy. God forbid they should ever have to fight a war. They raised no objections at all to us making the film, but it just took months and months. We approached them in July and I guess we got a few interviews by November. In Tahiti the challenge was finding really good, bona fide, cases of people who had been irradiated. Because the doses of radiation, on the whole, were very low, most people were not affected. For those who were, whatever problems they had were only going to show up 30 years later, so it was very complicated.

BBC Four: The film contains some remarkable footage that the French military took of the tests. What did you make of that?
BL: I get the impression from watching the film that they thought they were doing nothing wrong whatsoever and were conducting completely safe nuclear tests.

BBC Four: They also appear very surprised when the wind changes and the mushroom cloud shifts direction.
BL: Yes, they obviously hadn't thought that through. They had a weather forecast, but it was wrong. Lots of people have been wrong about the weather, but not in connection with letting off a bomb the size of Hiroshima.

BBC Four: Why did France think they needed a nuclear programme?
BL: In the 1960s they saw themselves as a great power - and a great power that needed a nuclear bomb. From that perspective they can't really be faulted. They were the only power on the UN Security Council that didn't have a nuclear bomb. Where they can be faulted is that they don't seem to have thought about how it might have benefited them to be the only anti-nuclear power on the Security Council. That might have done more for their international standing. They were offered the American deterrent, like the British, in the mid-60s and they turned it down.

BBC Four: The early parts of the film do show yet another chapter in poor US-France relations.
BL: Yes. You also have to remember that De Gaulle pulled France out of Nato in 1966. They just weren't prepared to sit under the American nuclear umbrella any more than they were prepared to be part of any broadly American foreign policy.

BBC Four: It's interesting to see the sinking of the Rainbow Warrior in 1985 within this broader story. How did you approach that?
BL: We landed an interview with Pierre Lacoste, who was head of the French secret service when they sank the Rainbow Warrior. He had written a book that mentions France's involvement in the sinking, but I can't remember seeing him on TV. So we can't claim that he was delivering information that no one had before, but it does seem to be a television first. I thought what he said was so revealing about the French mentality. They feel picked on so they react aggressively and rather stupidly. Everyone then criticises or laughs at them so they feel even more picked on, so do something equally foolish or aggressive. The pattern just seems to repeat itself.

BBC Four: The other interesting interviewee from that perspective is Bruno Tertrais, the French nuclear weapons advisor.
BL: I put the questions to him and I think I gave him the space to answer them as he wanted to. It's amazing that today; even young people linked to the French state think that these tests did no real harm to anyone nearby, were conducted safely and brought France some sort of international diplomatic benefit.

BBC Four: How big is the independence movement in Tahiti at present?
BL: It's pretty big now. Not so much because the Tahitians hate the bomb, but because the French are no longer testing so the people are left high and dry. It's a Catch-22. France ploughs in all these subsidies but the whole place has become skewed because it no longer has this huge nuclear industry. The point today though is that the new president, Oscar Temaru, used to be an anti-nuclear campaigner so for the first time the pro-independence party has the majority of seats in Tahiti.

BBC Four: Finally, what do you hope the reaction to the film will be in France?
BL: Livid! In my fantasy world the head of the French television station comes up to me and says that it's an absolute scandal that an English director made this film. And I look him straight in the eye and say, "You know what? I also think it's an absolute scandal that a French director didn't make it". Of course, they are going to claim I'm picking on them, just as they always do.