Interviewed by Stephen Applebaum

Political film-maker Costa-Gavras turns his attention to World War II with a film that looks into why the Vatican didn't speak out against the Nazi concentration camps.

What research did you do for "Amen"?

A lot of books have been written about this subject since Rolf Hochhuth's play [The Representative] appeared in 1963, and I went through something like 15 or 20. Different historians have different positions but the element they are all sure about is that the Pope didn't speak. The last Pope did something extraordinary: he created a commission from Jewish and Catholic historians and they worked on the archives that the Vatican had published after the play. After two years they split, saying, "We don't know why the Pope didn't speak because all the necessary archives are not open." So that's the situation.

Do you hope to influence politics with your films?

I think the best thing that can happen with a movie, this one in particular, is it creates debate around a subject. I don't believe movies can change society, fortunately, and I hope not human beings. People must see the movies, read the books and then decide for themselves.

Why do you adopt a suggestive rather than a direct approach to the horrors of the Death Camps.

I believe, strongly, that the images we have seen from this period are so strong that cinema cannot reproduce them. It's impossible to take actors and extras, and say, "Now get naked and feel like Jews who have been gassed." Besides, I’d feel ridiculous saying that.

Given the kind of films you make, would you like to explore the dynamics that lay behind September 11?

Possibly, it's an interesting subject. The way the American government is approaching terrorism right now is the most dangerous way, and I'm afraid Hollywood will follow because it's more dramatic and much more satisfactory for the American audience. Probably one of the big stars will find a way to save the world again and again from terrorism. That's my fear. I hope I'm wrong.