The strange start of this film — all the time spent describing the cosmopolitan melange of the Algerian casbah travelogue-style — is the key to understanding what’s happening inside the typically clever head of notorious jewel-thief Pépé le Moko. The man is an archetypal old-school gangster, and he is so secure in the riot of the casbah that even the Algerian inspector has a friendly rivalrous relationship with him.
For a man of his magnitude, however, even being lord of a microcosmic world is not enough. When he falls for a French kept woman, he is reminded of all the things he has chosen to leave behind. The inspector uses this knowledge to his benefit, bides his time, participates in some carefully planned misdirection, and ultimately nabs his man when he leaves the casbah in love-lorn-and-lost pursuit of what he has thrown away. In the end, he realizes that even a prison of his own choosing is still a prison. Too late.
Though this fits the style of noir, I don’t know that it fits the technical definition. There’s plenty of chiaroscuro, and the subject matter fits the bill as well, but thematically there’s less grit and grey-morality than most other examples of the genre.
Jean Gabin is a great rascal.