A towering undertaking

The Book of Genesis tells us that God was so angry at the hubristic plans of humans to construct a gigantic tower stretching from Earth to Heaven that he gave every person their own language, thus ensuring they could not communicate and would be scattered around the world. In Babel, Alejandro Gonzalez Inarritu's sweepingly ambitious new film, a single act of violence turns out to have profound consequences for four different families across three continents.

'I came up with the idea of one act that can cause ripples around the world, triggering stories in different languages that would never cross, but would be connected emotionally and dramatically,' the Mexican director explains.

And so we have a Berber shepherd-boy in a Moroccan desert firing a hunting rifle at a tourist bus, gravely wounding an American woman (Cate Blanchett) travelling with her husband (Brad Pitt). Meanwhile, the couple's Mexican nanny has decided to take their two young children across the border to Tijuana for her own son's wedding. And in Tokyo, a teenage deaf-mute girl (Rinko Kikuchi) is struggling to cope with the death of her mother.

'To me, the film is like a river of emotion, flowing around the world,' he adds. 'If you stop to question every piece in the jigsaw, it doesn't make sense.'

Following on from Amores Perros and 21 Grams, Babel is the third in a trilogy of films from Inarritu. All three bring to mind Jean-Luc Godard's famous maxim - that a film should have a beginning, a middle and an end, but not necessarily in that order - in the way they scramble chronology and interweave several stories.

'For me, my style of storytelling is defined by the content: that's what comes first,' explains the 43-year-old, who began his professional life as a radio DJ in Mexico City. 'It's like you decide to drink champagne, and then you find the right glass to drink it in. If you drink it from a tequila glass, it will taste different.'

Inarritu moved to the United States just four days before the September 11 terrorist attacks in 2001 and quickly found himself the subject of suspicious glances from passers-by.

'It is strange being a Third World country citizen in a First World country, especially under the regime of Bush,' he reflects. 'Yet, for me, as an artist, leaving Mexico has been very productive; it has taken me out of my comfort zone. With Babel, I wanted to make a film about all those themes that were filling my heart and my mind.

It's clear that Babel is a project with immense personal resonance. As a teenager, for example, he travelled to Morocco, paying for his way by working on a freight ship. 'It was a revelation,' he smiles. 'Here was another country with a completely different religion and traditions, and it was beautiful at that time - partly, I think, because of the hashish. At that age you absorb certain things and it really opens your eyes.' It was while visiting the sulphurous springs of Hakone in Japan that he noticed an elderly man helping a disabled girl, an image that inspired the Japanese section of Babel. And to renew his US visa, Inarritu must regularly drive across the border to Tijuana, a journey undertaken in the film by nanny Amelia (Adriana Barraza).

Working with regular collaborators screenwriter Guillermo Arriaga, cinematographer Rodrigo Prieto and production designer Brigitte Broch, Inarritu spent almost a year shooting Babel, dealing with challenges such as suffocating daytime temperatures in Arizona's Sonora desert.