Conversely, in a sequence reminiscent of Lang’s morally investigative “M,” Harry Styles’ Alex leads a witch-hunt targeting an imposter inside a landlocked boat taking fire. They wait for the tide to wash the boat to safety, a process that either takes three hours or six—they aren’t sure—but as the hull takes fire they grow desperate. One of them, it seems, must flee the boat to lighten the load so more may live. It is revealed that a French soldier named Gibson (Anuerin Barnard) stole a British Uniform to escape the beach, and in terror and paranoia, Alex turns guns on Gibson to force him off the vessel and to his death. Gibson and Alex are separated by nationality and politics, but as in Clouzot’s “The Wages of Fear,” none of that matters if you’re not still breathing. Presented without judgment, the manner of how things get done—such as the steps of getting a boat off to sea—inform the choices these men make to survive. Consequently, no war film has ever been so concerned with the behavioral arithmetic of a war zone. Each tiny decision has an action and reaction, cause and effect, and Nolan is fascinated in how those small processes add up to the salvation of hundreds of thousands of men.

And this is where Nolan declares his own version of the “Dunkirk Spirit” itself, wherein our existential survival instinct as a species overwhelms the selfishness of self-preservation (brought to life by Farrier’s sacrifice especially). Not many movies try to balance the extreme intimacy of the individual with an almost abstract notion of “species”—there have been examples, notably two of Nolan’s favorites, Terrence Malick’s “The Thin Red Line” and Stanley Kubrick’s “2001: A Space Odyssey”—but for Nolan these ideas are the counterweights that hold the movie together. All of this works through “Dunkirk”’s innovative time-thawing structure (something only Nolan’s would think of, let alone execute), and it’s from that structure that “Dunkirk” can ultimate manifest, or blossom, in our mind’s eye.

Constructed as a tightly wound ticking clock across three distinct stories— land, air, and sea—“Dunkirk”’s structure has them running at different speeds and they collapse into each other like waves on the surf. The most daring aspect of “Dunkirk” is only understood through the broader context of everything else the movie is doing. Always a defining character and often an enemy, time is an integral part of each Nolan film, this one most of all. “Dunkirk” slowly melts multiple experiences of different people in different times into single impressionistic moments. A striking example comes when Nolan cuts to day, to night, and back to day again, wherein we meet two contrasting soldiers. One is kind, the other dangerous. We’re introduced to one of them as Mark Rylance’s sailboat captain rescues a shell-shocked soldier adrift at sea, the victim of a U-Boat torpedo. Overcome with emotion, he attacks Rylance’s crew and inadvertently murders a boy (Barry Keoghan). Soon after, we meet the second soldier at night, gently escorting the victims of another U-Boat torpedo back to shore. Through the poetic irony of “Dunkirk”’s structure, these two soldiers are actually the same man: Cillian Murphy’s “shivering soldier.” Before the trauma, and after. Nolan challenges our point of empathy as we experience contradictory emotions simultaneously; should we feel equal sensitivity towards heroes and cowards alike?