One of the biggest risks of making a historical war film, let alone about a specific attack, is that the ending tends to be something of a fait accompli. On the one hand, that can rob historical war films of much of their suspense and tension, but it can also turn them into some of the most jingoistic and desperate efforts to build consensus around cinema as a vital medium. In Dunkirk, Christopher Nolan manages to somehow avoid both those pitfalls despite taking one of the most iconic moments in World War II as his subject matter, making for his best film since The Dark Knight and a distillation of all the best parts of the films that he has directed in the interim. In part, that’s because he has made the slightly odd choice to construct a war film around an evacuation, rather than a battle, with the film detailing the removal of over 330 000 British soldiers from the beach of Dunkirk from 26 June to 4 May, 1940. Hailed as one of the great miracles of World War II, the soldiers were ferried out by a combination of military and civilian merchant vessels under heavy bombing from the German air force, in a strategy that was commemorated in Winston Churchill’s famous “We shall fight them on the beaches” address.

There is, however, very little of the Churchillian about Dunkirk, which seems to be both closer to and more distant from the events it depicts than the regular historical record. In large part, that’s because of Nolan’s unusual structure, which presents us with three distinct timelines in the build up to the evacuation. First, there are the events taking place at “the Mole” (the long jetty that was used to land boats) in the week leading up to the evacuation. Second, there are the events taking place on the English Channel in the day leading up to the evacuation, as a variety of civilian vessels set off from ports on the Dorset coast to supplement the British navy. Finally, there are the events taking place in the air over the Channel in the hour leading up to the evacuation, as the British air force head to Dunkirk in order to ward off the German pilots. In other words, the action shifts between what is occurring a week, a day and an hour before the evacuation, while these timeframes also shift between what is occurring on the beach, on the water and in the air above the water.

More specifically, these competing timeframes indefinitely postpone the actual moment of evacuation while also evacuating the entire film of everything except sea and sky, until the approach to Dunkirk gradually comes to feel as if it has overtaken the evacuation itself. At one level, it’s hard not to see that as an allegory for the difficulty of approaching and representing such an iconic historical moment – especially from such a distance – with the film seeming to displace its own subject matter as it proceeds. Similarly, this continual relegation of Dunkirk to a threshold, rather than a foregone conclusion, works beautifully to capture the sense that this was indeed the last real threshold between Germany and Britain, and that it was this threshold that was the real space of contention and conflict. Indeed, at moments it almost feels as if the approach to Dunkirk is a kind of evacuation in itself, a departure from the previous security of England as the characters head towards destruction to fight for that security one final time. That sentiment is particularly clear in the final scene, in which one of the pilots, played by Tom Hardy, finds himself running out of fuel just after the evacuation has ended. Forced to glide on, indefinitely, he moves far beyond the chaos and confusion to eventually touch down on a wet, distant beach, subsumed into a seamless synthesis of sea, sand and sky, and a splendidly summative image of the evacuation, if only because of how it has already overtaken what the individual soldiers can know of it.

Even before that point, however, the evacuation feels dissociated from any one historical moment or political cause, with the different timelines never quite converging into any definitive gesture or spectacle. Instead, they simply evacuate the mise-en-scene more and more, as if to open up the action to the miraculous and beneficent hand of a guiding power, even if that power is merely Nolan’s direction and Hoyt van Hoytema’s cinematography. As a result, Dunkirk itself seems to exist in a state of perpetual anticipation but to have also exceeded every way in which it will be represented and remediated, dreaming of imminent destruction but also of the apocalypse as a distant memory. Crucial to that strangeness are Nolan’s incredible compositions, which evoke a fragment of World War II that has been jettisoned from space and time and set adrift in a primal, planetary fusion of sea and sky, which eventually makes it feel as if the action is taking place in a totally submerged world, as soldiers cling to one sinking structure after another and water floods in from every angle. Indeed, by the end of the film, Dunkirk is more about soldiers eluding sea and sky than anything else, with even the land collapsing into the ether as the tide turns so many times that not a single piece of ground feels cemented to the earth’s crust.

While Nolan has always experimented with time, these later moments feel particularly indebted to Interstellar. On the one hand, Dunkirk clearly recalls the unnamed planet of Interstellar that was entirely occupied by ocean (and which was also the planet that, initially, most resembled Earth). More pervasively, the approach to Dunkirk seems to be modelled on the approach to Gargantua, with both destinations forming a kind of event horizon or point of singularity that distorts and bends time as the characters move closer to them. In lieu of the “real time” footage that made Saving Private Ryan so groundbreaking, Nolan instead presents an unreal time, in which the different events of the evacuation remain so incommensurate with each other, and with the present, that we might as well be watching science fiction. Certainly, the scale of the sea and sky is pitched at that of science fiction, especially once the small civilian vessels arrive to throw everything around them into even more sublime relief, as every single human exchange cowers under the heightened awareness of the sky that descends when there is literally nowhere left to hide.

As the sky looms, Dunkirk also feels indebted to The Dark Knight Rises, since it was there that Nolan first envisaged his passion for high spectacle in terms of terrorist spectacle. After all, no contemporary film maker is as obsessed with spectacle as Nolan, and no contemporary spectacle is as powerful as that of terrorism. More specifically, terrorist spectacle tends to operate much like the depiction of Dunkirk here, evoking an attack that is always imminent but has somehow always exceeded any subsequent attempt to represent it as well. Terrorism, like the evacuation of Dunkirk, works by displacing spectacle from the present moment, turning it into something that can be anticipated and commemorated, but never properly experienced, if only because to experience it is to be consumed by it, for both victim and perpetrator. In that sense, it often feels as if the fractured timelines of Dunkirk are a way of gesturing towards the unimaginable horizon that occurs right on the very threshold of a terrorist attack, with the first distant tremors of each new wave of aerial bombing functioning in much the same way as the first inchoate rumblings of Bane’s attacks throughout New York City. It doesn’t hurt, either, that Tom Hardy wears a gas mask for the entire duration of the film, in a clear nod at his performance in The Dark Knight Rises.

Of course, The Dark Knight Rises was explicitly about terrorism, and superhero depictions of terrorism – that’s what allowed Nolan to clarify his approach – while Dunkirk seems to deal with events that are far removed from the peculiar paranoia of the present. Yet as the action becomes more displaced from its original context, Dunkirk arguably offers an even purer vision of how it feels to live in an era galvanised by terrorist spectacle. While the English boats and planes may move further away from home, Dunkirk never quite seems to arrive in France, let alone return to England. At the very least, France and England are irreversibly transformed by the processes of arriving and returning, as if to evoke a world in which the sheer act of apprehending terror changes the world, and rearranges all the thresholds and barriers we previously took for granted. Perhaps that’s why so many viewers have reported finding the film so terrifying, and so sickeningly suspenseful, since there is no real catharsis or cessation of suspense by the end, but just a sense that the thresholds responsible for regulating suspense have been ineradicably shifted.

In that sense, the greatest formal achievement of Dunkirk may be the way in which Nolan manages to elude anything resembling an conventional climax without his film ever feeling either intentionally or inadvertently anticlimactic. For all that the screenplay may follow a handful of soldiers home, it really feels as if all of them are in the same position as Tom Hardy’s pilot, who simply continues gliding on after having contributed to the evacuation, before touching down in a strange zone that is neither England, France nor Germany at this particular point, and whose status can only be cemented in the future. Yet, in a very real way, this pilot has come home even more emphatically than the other soldiers, since it’s clearer to him than to anyone else that the definition of home has changed in the very process of fighting for it. In these astonishing final moments, Dunkirk is neither a film shot in the present tense nor a film shot in the past tense, but a film shot in the future perfect tense – a vision of what will have happened when history finally deems itself to have traversed the threshold upon which Nolan poises one of the greatest war films of all time.