A common response to television coverage of the 2001 attack on the World Trade Center was that it looked like a film. Conversely, the most striking thing about United 93, the first fictionalised feature to be made about the events of 11 September 2001, is that it bears little resemblance to a conventional motion picture.
Hand-held cameras, unknown actors, action played out in real time - this is not what films are usually like. But the British writer-director Paul Greengrass, who pieces together events culminating in the crashing of the hijacked United Airlines Flight 93 in a Pennsylvania field, faced an unusual challenge in shaping his film: how to repackage, as cinema, events that were inherently cinematic to begin with, and which have been repeated endlessly in our imaginations. The 9/11 attacks were an orchestrated spectacle that relied for its impact on epic imagery and an audience of billions. No film-maker can compete with that.
By concentrating on the flight that was given least media coverage, Greengrass avoids recreating the events most clearly imprinted on our memories. Oliver Stone faces more of a problem with his forthcoming 9/11 film, World Trade Center. Naturally, many believe that the most fitting tribute the bombastic Stone could pay to the victims of the attack would be to leave the subject well alone. Yet even Stone's supporters must see the difficulty inherent in attempting to recreate the sheer visual impact of the atrocities.
Perhaps this difficulty, as much as public sensitivity about the issue, is the reason why cinema has been relatively slow to respond to 9/11. Novelists have been much quicker off the mark, with writers including Neil LaBute, Jay McInerney and Jonathan Safran Foer examining the attacks in their work. There have been two portmanteau films - 11'09"01 and the documentary Underground Zero - both of varying quality. Television has got in on the act with documentaries such as Discovery Channel's The Flight That Fought Back (2005). Narrative cinema, in contrast, has addressed that day only through echoes and allusions.
Films that have been touched unintentionally by the shadow of 9/11 have found themselves dwarfed by its resonances. The likeable coming-of-age comedy Raising Victor Vargas acquired a strangely downbeat aftertaste when it emerged that it was the first picture shot in New York after the attacks. And it was impossible not to play spot-the-twin-towers with any film made there before 9/11, the most melancholy example being Steven Spielberg's AI: artificial intelligence, which opened in Britain just weeks after the attacks. AI imagined the city of New York underwater, complete with a fully submerged World Trade Center. Rarely has a vision of the future dated so suddenly, or so comprehensively.
Spielberg snatched back the image of the twin towers last year by using it as the pay-off shot in Munich, tilting the camera up from a lone Mossad agent to observe those eerily flawless columns on the 1970s skyline. One of Spielberg's peers, Martin Scorsese, also conjured up the ghost of the World Trade Center to round off a period piece: his Gangs of New York (2002) ended with the towers intact, looming at the close of a brief dissolve through the city's changing horizon.
Film-makers have occasionally been guilty of invoking 9/11 in pursuit of borrowed significance. Spike Lee used the razed towers as a symbol of his charac-ters' wounded masculinity in 25th Hour (2002), and Denys Arcand lazily replayed shots of the planes hitting the towers in The Barbarian Invasions (2003). The worst culprit of 9/11 exploitation was Richard Curtis, who shoehorned a reference to the attacks into the opening voice-over in Love Actually (2003). The prime minister, played by Hugh Grant, substantiates his claim that "love is all around" by recalling that passengers on the doomed planes sent messages of love, not hate, in their final moments. What was, for those victims, an act of sincerity and desperation becomes in Curtis's hands a presumptuous grab at gravitas for his otherwise whimsical comedy. I like to think that Working Title, the production company behind both Love Actually and United 93, made the latter film to settle the karmic debts incurred by the former.
Given the wealth of possible pitfalls, it was judicious of Michael Moore to abstain from rerunning images of the World Trade Center attacks in Fahrenheit 9/11 (2004). Instead, Moore played the sound of the attacks over a black screen; we supplied the pictures. In complete darkness, deprived of the morbid comfort that had arisen from repeated viewings, we experienced the horror afresh.
This seems to me to suggest a way forward for cinematic treatments of the attacks. As well as being respectful to the victims, any film which addresses that day should repackage imaginatively the familiar trauma so that it hits us again, or hits us differently. A comedy about 9/11 might seem distasteful, but there will come a time when laughter will be an appropriate means of absorbing the shock. There is no danger that the day will be forgotten, only that we may settle too snugly into comfortable modes of remembrance.
United 93 goes on general release on 2 June. World Trade Center opens in the UK in September