Apart from the usual Powell & Pressburger and David Lean masterpieces, I have steered rather away from the great British war movie during my cinematic peregrinations. Growing up in the UK, one did get rather tired of hearing about these films, spoken of in terms of nostalgia and sentiment. This kind of admiration for movies based on their respectable subject matter rather than their artistry felt like exactly the kind of patriotic attitude to film culture that kept Michael Powell languishing in obscurity for so many years.
But in my mellow senescence I can appreciate these movies a bit more. Dunkirk is an interesting flick. On the one hand it's an epic, with armies of extras, special effects, and a narrative sweep that takes almost the whole first act of WWII, from the British perspective. On the other hand, it's a product of Ealing Studios, best known for comedy but ideologically attuned to celebrating group efforts, community, the little fellow, and more interested in perfect miniatures than bestriding colossi.
The filmmakers square this circle in a number of ways. Least successfully, they open with twenty minutes of grainy exposition, folding in newsreels, headlines, singalongs, satirical cartoons, and awkward exchanges between minor figures never to be met with again (what in gaming are called "non-player characters"). Amusingly, with the passage of time, all this footage probably wouldn't be that helpful to a viewer without some knowledge of the Second World War. The audience, if it really exists, who require helpful captions reading "Berlin, Germany," are likely to be a little lost at first as they're plunged into "the phony war," that period before the fall of France in which life in Britain seemed to go on much as before and people were starting to wonder what all the fuss was about.
Once this is over with, the campaign can essentially be reported via two microcosms: one narrative thread follows a half-dozen British soldiers separated from their unit and trying to get home, while the other concentrates on the British boat-owners who eventually answered the call to rescue hundreds of thousands of British soldiers from French beaches. This heroism is celebrated in William Wyler's rosy wartime view of Hollywood England, Mrs. Miniver, but we're in for a grittier account here.
Norman was a solid middlebrow filmmaker, but he had a real gift for dynamic blocking and camera movement. He marshalls his considerable resources well, though it's always disappointing when these movies fall back on stock footage to put over their effects. If the answer to your problem is stock footage, you haven't got an answer to your problem.
The cast is remarkably un-starry, which helps with conviction, but in the principle roles are Bernard Lee (M from the early James Bonds), Richard Attenborough, and John Mills, all fairly inevitable casting for British wartime action. A useful measure of the contrast between British and American war movies can be attained by comparing John Wayne, who played members of every branch of the US armed forces (plus the RAF) in just about every major conflict of the twentieth century, and England's equivalent, John Mills, a former chorus boy, an everyday sort of chap, short of build and with the face of an earnest terrier pup.
The film's boldest stroke is when the two narratives meet, the flotilla of rescue boats having reached Dunkirk and a couple of crews having been stranded along with the British tommies. Masses of men lying on a great expanse of sand has a surreal, Daliesque appearance. And this sequence goes on for ages, with the boats unable to rescue the men due to attacks from the air, the defenses gradually falling back, the heroes reduced to doing what we British have always done best: queuing and grumbling. A sense of desperation sets in among characters and audience alike, and the film is unrelenting. At least as far back as the Charge of the Light Brigade, the Brits also have a strange habit of celebrating our military disasters, but this one is double-edged. The film convincingly argues that defeat in France united the nation, and the successful rescue of (most of) our troops showed what we could do if we all pulled together. Which is the favourite message of Ealing films.
(Though I still prefer The Ladykillers and Kind Hearts and Coronets, movies gloriously devoid of any redeeming social content or morality.)