Babel is a huge, messy, sensuous film, its 142 minutes stretched over such riches as an embarrassingly intimate scene in which Cate Blanchett struggles to steady herself over a bedpan, a startlingly cheerful moment in which suburban American children are subjected to the slaughter of a chicken, and a lovely, turbulent sequence in which a deaf Japanese schoolgirl (the fascinating Rinko Kikuchi) takes Ecstasy and goes out dancing. Sometimes, we hear the music she doesn't hear; at other times, the narrow melody cuts out, and we eavesdrop on her silence—a thumping murmur that sounds like the beating of an underwater heart.
The movie is clearly of a piece with Amores Perros and 21 Grams, the previous collaborations between writer Guillermo Arriaga and director Alejandro González Iñárritu; for the third time in the trilogy, there are three storylines contained in one, a narrative catholicity that seems almost Catholic. But Babel is also being compared to Crash, a secular ode to diversity and coincidence that irritated as many people as it pleased. The narrative contingencies in Babel are delicate, but they're not incredible: Chances increase the larger the sample size, and Babel takes on the entire world. The only thing viewers may find hard to forgive is the ambition required to force three nonlinear stories—one set in a remote Berber village in Morocco, one in Tokyo, and one on the border between the U.S. and Mexico—into a single film.
A Japanese man traveling in Morocco gives a rifle to a goatherd, whose son accidentally shoots an American woman, whose government wildly overreacts. Meanwhile, the young son and daughter of the hemorrhaging woman are taken to a wedding in Mexico by their immigrant nanny; as the exhausted revelers return to California, U.S. border control guards provoke another wild overreaction, and the kids end up stranded in the desert. In the story with the most tenuous connection to the rest, a deaf Japanese schoolgirl tries to get laid or at least touched by other human hands. Each of the stories concerns parents and children, and each is preoccupied with the arbitrary yet unbridgeable borders between people. It sounds like nauseating humanist blather—people are people are people, and cinema can bring us together—but I think it's smarter than that.
Despite the title, the borders in Babel aren't manufactured by a furious God. They're explicitly human ideas, with unfortunately human means of enforcement. In other words, they're anything but humane. When Blanchett, playing a nervous harpy whom you can't wait for a deus ex machina to step in and shut up, starts to bleed to death on a dirt floor, your feelings immediately swing the other way, aided by sympathetic close-ups of faces and hands. (Brokeback Mountain's Rodrigo Prieto is the gorgeously tactile cinematographer.) The American government, however, responds with an aggression intended to protect the body politic, even if it means sacrificing an individual citizen: The military turns back a Moroccan rescue helicopter, fearing the Moroccan government was complicit in the attack. A similar protective instinct gone sickeningly rigid is at the heart of the Mexican/American story, where fear at the border pushes the children into mortal danger.
Not all of the borders in the film are political, or even destructively enforced. There are the inevitable linguistic borders (in rare form for a major Hollywood movie, viewers will be expected to read subtitles translated from such languages as Arabic, Berber, Spanish, Japanese sign language, and Japanese); there are incest taboos (a Moroccan boy is scolded harshly for peeping at his sister as she dresses). These, too, are lines drawn by culture, but the filmmakers certainly don't argue they should be scribbled out.
The filmmakers don't argue much of anything, in fact, except look here, look there. It's a movie about images and textures and film grain; the acting, while strong, is merely an infrastructure for beauty and feeling. (Blanchett does beautiful pain, Brad Pitt is responsible for beautiful anger, and Kikuchi takes care of beautiful isolation. Everyone else is there for beautiful powerlessness.) It isn't an intellectual film, but it will make you dissolve under the weight of its simple, ineffable ideas. 
Read an interview with Alejandro González Iñárritu, in which the director amicably disagrees with almost everything Annie Wagner suggests.
