“Allied” is an unapologetically old-school movie, the type of World War II romantic thriller that one could easily visualize Humphrey Bogart or Clark Gable starring opposite someone like Hedy Lamarr some 70 years earlier.

Fans of that genre probably will like this film as well — an entertaining but unpretentious drama that admittedly is somewhat less interesting than the rumors it inspired.

Brad Pitt stars as Max Vatan, a Canadian-born Allied intelligence officer who parachutes into North Africa during the early days of World War II. In Casablanca, no less, he hooks up with French agent Marianne Beausejour (Marion Cotillard). He will pose as Marianne’s husband as cover for their assignment, the assassination of a German diplomat at a reception.

It doesn’t take a genius to foresee that Max’s and Marianne’s cool professional relationship will eventually turn romantic. Screenwriter Steven Knight gets some creative points, however, for staging their first love scene in the front seat of a car during a desert sandstorm.

Miraculously surviving what appears to be a suicide mission, Max and Marianne make their ersatz marriage official and relocate to London, where they raise their baby daughter.

Their idyllic relationship is threatened, however, when Max is informed that his wife is suspected of being a German spy. Despite warnings to leave the investigation to the professionals, Max flies behind German lines in an effort to discover the truth.

Director Robert Zemeckis keeps things moving at a brisk pace — an undeniable asset in handling a plot that reaches a dramatic high point when Max demands his wife play the piano. Fortunately, this scene plays better on screen than on paper.

Pitt plays Max so stoically, at least until the climax, that he appears to be channeling his inner Ben Affleck. In a film devoid of significant supporting roles, that allows the luminous Cotillard to run away with acting honors. She is convincing as both a devoted wife and potential spy.

The making of this film wound up being fodder for the tabloids, after allegations surfaced that Pitt’s off-screen relationship with his co-star helped break up his marriage to Angelina Jolie. Cotillard not only denied those rumors, but revealed she was pregnant by her long-time companion, French actor/director Guillame Canet.

If Pitt and Cotillard were romantically involved, you couldn’t prove it by this film. Sometimes off-screen sparks show up on-screen (Bogart and Lauren Bacall in “To Have and Have Not”) and sometimes they don’t. In the 1987 sci-fi parody “Innerspace,” for example, Meg Ryan generated more chemistry with Martin Short than with future husband Dennis Quaid.

In any event, the love scenes in “Allied” are respectable but fall far short of sizzling.

The same description could apply to the film as a whole.