THE final part of Alejandro González Iñárritu’s trilogy, which began with Amores Perros and continued with 21 Grams, is a stunning piece of cinema. It was inspired by the biblical story and explores divisions between cultures, families and couples, and the tragic loneliness that binds us all.

This was one of the most eagerly awaited films in competition for the Palme d’Or at Cannes and it doesn’t disappoint on any level.

The director is fearless. His film swivels around three profoundly affecting stories set on three continents and linked by an act of childish stupidity: two young Moroccan boys, testing out their new hunting rifle, accidentally shoot an American tourist (Cate Blanchett) in the neck. Her frantic husband, Brad Pitt, forces the driver of their tour bus to stop at the nearest village to find help. The terrified passengers are eager to abandon them.

Back home in San Diego, the Mexican nanny of Pitt and Blanchett’s two children takes them on an ill-fated journey across the border to attend the wedding of her son.

In Tokyo the businessman who had given the rifle to a peasant in Morocco grieves over his wife’s suicide while his deaf mute daughter goes looking for sex and escape in nightclubs.

Like the two previous parts of the trilogy, Babel is a story about parents and children and the profound sense of isolation that occurs when intimate links are broken.

Some scenes are so intense that I could barely bring myself to look at the screen. The mountain shepherd who tries to stanch the wound in Blanchett’s neck with a needle and thread is just one.

The elderly nanny, dumped by her panic-stricken nephew (Gael Garcia Bernal) in the middle of the desert at night with Pitt’s two children, is another. Iñárritu’s taste for vertiginous moments of panic is a hallmark of all his films. Here, they leave the viewer reeling. Yet nothing feels contrived or imposed. The creeping dread as these stories career out of control is brilliantly orchestrated.

The clash of cultures is mirrored by the landscapes. The parched poverty of the Moroccan Outback frames the futility and desperation as Pitt screams down the phone for help and an ambulance. The bitter irony is that in a world bursting with technology, we still fail miserably to communicate.

Other “borders” are subtly touched: the gap between adolescence and adulthood; the chill between husbands and wives; and the rift between men and women in a Muslim society.

The camera shuttles between continents without losing an ounce of momentum. Scenes of frustration and madness in Morocco and Mexico are spliced next to acts of erotic foolhardiness in Tokyo, where Rinko Kikuchi’s deaf schoolgirl is desperate to feel wanted and desired. Her disability makes her feel like a permanent stranger.

It’s a sentiment worthy of Samuel Beckett, and it comes from the heart of a tragic and terrific film.