Director Alejandro González Iñárritu and scripter Guillermo Arriaga’s previous collaborations, Amores Perros and 21 Grams, are composed in triads: three seemingly unrelated tales that are gradually brought into sync. So it’s apt that the two Mexicans’ partnership appears likely to end with their third film. González Iñárritu reportedly barred Arriaga from attending the Cannes Film Festival premiere of Babel amid conflicts over which of them was more responsible for their storytelling’s elaborate architecture. The split may not be such a bad thing. The multilingual Babel is the men’s most ambitious and wide-ranging movie but also their worst.

The structure is essentially the same as in 21 Grams: Shards of three different stories slip and slide through adjacent time periods as their fateful link gradually comes into focus. But where 21 Grams (and its somewhat more linear predecessor) were set in a single city and linked by a single event, Babel lunges from Morocco to San Diego/Tijuana and then, incongruously, to Tokyo. Despondent over the death of their newborn child, Richard and Susan (Brad Pitt and Cate Blanchett) are on a group vacation in Morocco. Back home, Mexican housekeeper Amelia (Adriana Barraza) decides to take the couple’s surviving kids, Debbie and Mike (Elle Fanning and Nathan Gamble), to her son’s wedding on the other side of the border, a trip chauffeured by Amelia’s hotheaded nephew Santiago (Gael García Bernal). And in Japan, deaf teenager Chieko (Rinko Kikuchi) bickers with her father (Kôji Yakusho) and desperately seeks affection.

Some observers have done the math and decided that Babel has four stanzas, because it also tells of Moroccan goatherds Ahmed (Said Tarchani) and Yussef (Boubker Ait El Caid). But these young brothers are clearly part of Richard and Susan’s episode; Yussef is the one who, while trying out a new long-range rifle, inadvertently shoots Susan in the neck. If the tourists and the goatherds never actually meet, the bullet links them physically, and subsequent events connect them thematically. For the same thing is happening in Morocco as along the United States–Mexico border: Americans’ personal arrogance and national ideology are screwing up everything.

There’s something to that argument, but Arriaga and González Iñárritu present it with crushing artlessness. While Richard seethes over his wife’s critical injury, potentially endangering the lives of his fellow tourists, Susan doesn’t get quick medical attention because the U.S. and Moroccan governments are squabbling over American insistence that the woman’s shooting is a terrorist act. In the even more strident United States–Mexico plot strand, the Border Patrol poses as big a danger to Debbie and Mike as the State Department does to Susan. When he and his aunt are hassled at the border on the return from the wedding, drunken Santiago loses his cool and drives past the barrier. With cops in quick pursuit, Santiago dumps Amelia and the kids in the California desert. They wander helplessly, as the two blond tykes risk the fatal sunstroke that claims so many illegals, a development that roars beyond irony into the realm of spiteful wish fulfillment. Babel is a much cruder treatment of the border issue than was The Three Burials of Melquiades Estrada, which Arriaga wrote but González Iñárritu did not direct.

And what are Americans doing wrong in Tokyo? Nothing that’s mentioned in Babel, which doesn’t create a strong bond between Chieko and the other major characters. The film does eventually tie Japan into its worldwide web, but the linkage is freakish and barely thematic. (Since she’s deaf, Chieko has difficulty expressing herself, but despite the movie’s title, communication breakdowns aren’t central to Babel’s schema.) Chieko seems to exist just because González Iñárritu and/or Arriaga have visited Tokyo and were beguiled by its pulsing lights, new skyscrapers, and microskirted schoolgirls. The movie’s Japan chapter is basically Lost in Translation with a hard-on. Chieko roams with her pals, desperately looking for love with schoolboys and cops, and in coffeeshops and nightclubs (notably Shibuya techno landmark Womb, here called “J-Pop.”) When rejected, Chieko pulls off her panties and flashes her bare crotch, or strips altogether. The Japanese, apparently, are as randy as Americans are imperious and as Third Worlders are misunderstood.

Like the director’s previous films, Babel is beautifully shot and cunningly interlocked and boasts committed performances. Shot with handheld gusto by longtime González Iñárritu collaborator Rodrigo Prieto, the film includes some mesmerizing sequences, a few of which flirt with abstraction. Editors Stephen Mirrione (who also cut 21 Grams) and Douglas Crise skillfully rhyme the transitions: from scared Moroccan kids on the run to blithe American ones at play, from Susan’s scream to Chieko’s soundless world, from opium used to kill pain in Morocco to pills popped to relieve angst in Tokyo. Pitt and Blanchett cash in their movie-star glamour to effectively depict blood- and urine-stained desperation, and a cast of amateurs and first-timers—notably Kikuchi and El Caid—are as believable as the script allows.

While those things are admirable, they can’t overcome the film’s tidiness and didacticism. The impact of the director’s two previous features also dissipated as their shattered narratives were reassembled, but those movies retained some of their original vibe to the end. Babel, however, sacrifices all its atmosphere in its quest to tabulate human misunderstanding and score obvious political points. By the time González Iñárritu and Arriaga have made everything fit together, none of it matters.