There are two remarkable features of Stairway B, a new documentary on the 9/11 attacks. One is an interview with a Manhattan firefighter who recalls being trapped in the stairway of the World Trade Centre’s north tower as the building collapsed. Instead of the inchoate roar of destruction that observers might have imagined, he describes a terrifying rhythm: “You could actually hear the floors hitting one another — boom, boom, boom, boom,” he says, “ and I remember thinking to myself . . . ‘Oh, this is it. We didn’t make it’.”

The other salient aspect of the film is its long gestation. Its story is a near-miraculous episode from an otherwise apocalyptic day, yet it took five years to reach American screens. The same is largely true of Oliver Stone’s 9/11, while United 93, released earlier this year, shares the delay between galvanising moment and finished product, if not the uplifting ending. It ends, like the flight of the same name, in a smouldering crater in Pennsylvania.

That film would put viewers in “a near-perfect state of distress”, Martin Amis wrote in The Times. Today, in our books pages, he switches his focus from 9/11’s victims to its planners, and wonders at their sheer emptiness. Osama bin Laden, in particular, is an “omnicidal nullity”. The verdict is unarguable. It also helps to explain Western culture’s tentative and sometimes baffled response to a world-changing — yet surprisingly straightforward — catastrophe.

Few serious writers or film-makers have not somehow incorporated their reactions to 9/11 in their work since then. But fewer still have tackled it head on, partly for fear of being seen to exploit victims’ grief or the pornographically violent stock of imagery produced by those murderous 100 minutes; and partly on the assumption that their audiences had already been fed a surfeit of news footage that needed little captioning. Stephen Spielberg, the world’s most powerful director, eventually approached the subject, but via metaphor of H. G. Wells’s War of the Worlds.

It was left to Bruce Springsteen, New York’s own balladeer, to offer popular culture’s first direct response to the atrocities. As he recorded The Rising, an album of raw lamentation, Hollywood shelved every project that touched on terrorism, and the West busied itself in learning about a very different culture that it feared it had misunderstood. Sales of Bernard Lewis’s The Crisis of Islam soared.

When asked in 1949 for his view of the French Revolution, Zhou Enlai, Communist China’s first prime minister, replied famously that it was “too soon to say”. The same is doubtless true of the long-term impact of 9/11, but this much is already clear: it was a singular, unambiguous event, recorded in all its shocking immediacy from a thousand camera angles — and carried out by a “cornered troglodyte” to whom there is probably much less than meets the eye. As such, like Pearl Harbor, 9/11 may prove less engrossing to creative minds than its aftermath. Hollywood’s next Vietnam will not be the twin towers, but Iraq.