In August, 1944, Allied troops were converging on German-occupied Paris, and General Dietrich von Choltitz, the recently-appointed military governor, was preparing to execute Adolf Hitler’s order to bomb the city to bits before surrendering it, killing much of the population in the process. As he gave final instructions regarding the operation, Raoul Nordling, the Swedish consul-general, came to his headquarters and somehow persuaded him to disobey the Fuhrer’s directive and leave the French capital intact.

What was the reason behind the turnabout by the general, who was by all accounts a loyal and dedicated officer? That’s the question posed by Cyril Gely in his 2011 play, which director Volker Schlondorff (whose “The Tin Drum” won an Oscar in 1979) has adapted for the screen, utilizing a screenplay penned by the playwright himself. It’s not the first time the episode has been fodder for cinematic treatment. In 1966 Rene Clement directed “Is Paris Burning?,” one of those big-budget international World War II extravaganzas that bombed spectacularly at the box office, and two members of the massive ensemble were Gert Frobe as the general and Orson Welles as the diplomat. It followed the account in the book by Larry Collins and Dominique Lapierre on which it was based, to the effect that Nordling persuaded Choltitz to spare the city in return for a promise to save his family from possible execution—rather than the explanation given by the general in his memoir, which explained the decision as his determination that the action would be militarily futile and his belief than Hitler was insane.

Gely follows the Collins-Lapierre version, but Schlondorff’s treatment of the incident is much more elaborate and clever than the prosaic account in Clement’s film. Here, as befits what was in its origin basically a wordy two-character piece, the confrontation between the two men is far more complicated, filled with twists, turns, revelations and sudden reversals. As played in forceful fashion by Niels Arestrup, Choltitz is a gruff good soldier, yet hobbled not only by doubts but by illness—and by the fear that his actions could mean doom for his wife and children. By contrast Nordling, played by the cultured, well-spoken Andre Dussollier, is shrewd and calculating; he shows up in Choltitz’s plush hotel suite via a secret passage supposedly built by Napoleon III for visits to his mistress, and plays on what he perceives as Choltitz’s weaknesses while desperately trying to save the city he loves. The result is an elaborate verbal chess match of the sort that the stage loves, especially as it concludes with a nice checkmate, but that can shrivel up and die on celluloid.

That is doesn’t is testimony to the performances and to Schlondorff’s skill. It’s not merely that he opens up the piece considerably—giving us some outside shots and using archival footage, while collaborating with cinematographer Mathieu Amathieu, production designer Jacques Rouxel and editor Virginie Bruant to give variety to the interiors of Choltitz’s headquarters hotel as well. It’s testimony to their success that although nobody can be uncertain of the outcome—Paris is still the City of Lights, after all—“Diplomacy” still builds suspense, and in the end earns a sigh of relief.

Much of what happens in the film, of course, is purely conjectural. We know that Choltitz and Nordling met, of course, but not much more than that. What they said, how they said it, and what determined the outcome of their conversation, is all unknowable. And whatever transpired between them could hardly have been as smoothly choreographed as what we see and hear on screen. The actions of those around them—like the French engineer who plays a pivotal part in the denouement—are similarly speculative. But of course it doesn’t matter. “Diplomacy” is drama based on history, not history, and as such it’s a crackerjack example of it.

It also shows that Schlondorff, whose career has been erratic at best, hasn’t lost his touch. Like another veteran filmmaker, Roman Polanski, his turn to the stage for inspiration has proven a wise choice. And like “Venus In Fur,” “Diplomacy” is a winner, though of a very different sort.