A romantic spy thriller set during WWII starring Brad Pitt and Marion Cotillard sounds like a guaranteed winner. Alas, "Allied" is a muddle that sinks under the weight of its staginess and stiffness. Pitt does the movie no favors with a performance that verges on the somnambulant. Cotillard, bless her heart, tries her best, figuratively tap dancing like crazy. Director Robert Zemeckis and screenwriter Steven Knight don't bring the tension and vitality that a movie like this requires. At least the movie looks gorgeous; the sets and costumes are curated with loving attention.