What is the proper form for depicting chaos, loss and confusion? Drawing on seemingly incompatible sources - the documentary and action film - Paul Greengrass' UNITED 93 offers some tentative suggestions. Although it was produced and distributed by Universal, many critics have commented on how "un-Hollywood" UNITED 93 feels. However, to me, it cannily reworks some familiar Hollywood tropes in a new context. The most common criticism of recent American action films is that they're ineptly directed and edited, made with a sense of space that's utterly arbitrary: one never knows exactly where the characters are and what they're doing.

 This description is true of much of UNITED 93, but Greengrass' style is fiercely purposeful. The film is physically jarring. Handheld camerawork has become an overused signifier of realism, but on a huge screen, it can be (literally) nauseating. UNITED 93 made me so dizzy that I had to take a seat further back in the theater, the first time I've had such a reaction since  Lars von Trier's DANCER IN THE DARK six years ago. Much of the impact of UNITED 93 will be lost on the small screen.

Starting with his debut, BLOODY SUNDAY, Greengrass showed a knack for convincingly forging the illusion of reality. He's retained it, and it extends well beyond the handheld camera. For the first half hour of UNITED 93, the film cuts between the airport, NORAD and air traffic control centers. The workers - many played by non-professional actors  portraying themselves doing their real jobs - make small talk. Their speech is occasionally littered with jargon. It appears to be an ordinary day, but slowly signs accumulate, offering evidence that it's anything but, culminating in the two plane crashes into the World Trade Center and the hijacking of United 93. Greengrass shows an interest in institutional behavior reminiscent of Frederick Wiseman, with the difference that Wiseman shows how institutions work - or don't work but manage to perpetuate themselves - on an everyday basis and Greengrass depicts their collapse in the face of an unexpected event.

On FILM COMMENT's website, Gavin Smith writes that UNITED 93's " moral stance is that of a somber, uncompromising anti-spectacle." It threatens to break from that aesthetic once, making its only real misstep. Straying from the record, it suggests that passengers succeed in killing two of these hijackers. On paper, this might seem like a cathartic act of violence, but as Greengrass films and edits it, it's as confusing and fragmented a race into the void as the rest of UNITED 93. Some of the passengers behave as though they're in a classical narrative, but they're not.

UNITED 93 stirred some controversy when it opened the Tribeca Film Festival a few days ago. That ire should really have been directed at Jeff Renfroe's CIVIC DUTY, which I saw at the festival yesterday. Pretending to take post-9/11 racist paranoia as its subject, it winds up endorsing it for the sake of a dumb twist ending. Charges of exploitation would be far more aptly directed at Renfroe, who seems determined to prove that Indiewood can demonize Arabs as well as Hollywood. By contrast, Greengrass has given real thought to the political and moral implications of film style. UNITED 93 uses the power of the large screen to create a memorial  testifiying  to the dignity cinema still retains, even if it's become rarer and rarer.