Many of the greatest films of all time have some triumph-over-adversity story to buffer their mythology: a chaotic production, weak box office, critics that didn’t get it at the time, a loss to some forgettable film during awards season. Their greatness has to be elusive and mysterious, in other words, something that couldn’t be comprehended until later, when they finally got the full appreciation they always deserved. The path to canonization tends to have its own, often formulaic narrative.

That’s not what happened with Casablanca, which now celebrates 80 years of being widely beloved. Perhaps it wasn’t loved at the level that it is now – it was merely warmly received and successful, but not a sensation – but it won best picture, along with awards for its peerless screenplay and elegant direction, and is the rare film whose “classic” status is practically axiomatic. Who doesn’t love Casablanca? Or, put another way, where can you find any weaknesses in this production?

The jewel of Hollywood’s Golden Age, Casablanca is perhaps the best example of “the system works” in film history. It’s not the result of any one driving artistic force – though producer Hal B Wallis deserves the lion’s share of the credit – but an amalgamation of talent from every corner: a screenplay, by the twin brothers Julius and Philip Epstein, and Howard Koch, that’s a model of sophistication and wit; a superior studio craftsman in Michael Curtiz, who’d made The Adventures of Robin Hood with Wallis; a score, by Max Steiner, that seamlessly patched together existing elements, including the French national anthem; and, of course, the casting of Humphrey Bogart and Ingrid Bergman as exes whose love doesn’t amount to a hill of beans in a world too crazy to accommodate it.

The list of invaluable contributors must also include the supporting cast, too, which gives unique life to a North African city that serves as both refuge and purgatory to varying parties during the second world war. Foremost among them is Claude Rains as Louis Renault, a local police captain whose shameless corruption is also a form of political savvy, his way of handling an area of “unoccupied France” that nonetheless feels like disputed territory. The great Peter Lorre has a small but crucial role as Ugarte, a shady character in possession of two precious “letters of transit”, taken from two murdered German couriers, that would allow passage from Casablanca to neutral Lisbon and finally to freedom in the United States.

Ugarte is arrested for the crime, but not before leaving the letters with Rick Blaine (Bogart), an American expat who operates Rick’s Café Américain, a nightclub and gambling den that serves as a way station for stranded refugees as well as the Germans and Vichy French. Only a hardened cynic could run such a treacherous operation, and Rick, the ultimate bruised idealist, has exactly the right temperament: “I stick my neck out for nobody,” he says. That changes, however, when the woman who broke his heart, Ilsa (Bergman), strolls into the club with her husband, Victor Laszlo (Paul Henreid), a Czech resistance leader whom the Nazis are desperate to capture. The papers in Rick’s pocket are a valuable commodity to all parties – a test of his courage and the “sentimentality” that Louis suspects he still possesses.

Produced and released at a time that was nearly contemporaneous with the events on screen, Casablanca has the elements of a second world war spy thriller, but they serve to add stakes to a romantic pairing that’s outsized in glamour and emotion, but shrinks in face of global tyranny. Wartime love stories always have that push-and-pull between intense intimacy linking two people and the bombs that detonate around them, but Casablanca adds weight to the question of how much the pursuit of happiness matters when there’s so much more on the line. For audiences in 1942, trying to eke out some sense of normalcy during wartime, the dilemma surely resonated.

The more we learn about Rick – and the more we learn, along with Rick, about Ilsa’s own sacrifices and loyalties – the deeper their relationship gets, leading to a famously bittersweet scene on a foggy airport tarmac, when they put the world above themselves. There’s true magic in Bogart and Bergman’s scenes together, forged not only by their astonishing chemistry and charisma, but the grace notes in the dialogue, the soft caress of the lighting, and a score that builds evocatively around a song, As Time Goes By, which gets threaded into the film even when Sam (Dooley Wilson), the pianist, isn’t around to play it again.

In the end, though, the heart of Casablanca rests more with Rick and Louis, who close the film with its indelible last line. Here are two men coarsened by a war that has turned them away from their better selves, each perfecting their own form of practiced neutrality and stagecraft to survive one more miserable day. The Epsteins and Koch allot them all the best dialogue – “Remember this gun is pointed right at your heart”; “That’s my least vulnerable spot” – and put them in a situation that forces them to reveal the souls they’ve kept hidden as discreetly as any refugees in this shadowy North African enclave. Until he gets hold of a handgun in the final act, sarcasm is the only weapon in Rick’s arsenal.

Just as the war itself required group sacrifice and effort to win, Casablanca is our most enduring model of collaborative art, a union of talent and circumstance rather than a strong individual vision. What makes it so miraculous, in that respect, is that the studio machinery did not produce a film that ever seems factory-made, but more the result of shared passion from a stable of top-flight artisans. The sum of their efforts, at this point in history, feels downright patriotic.