Grade: C

For a film that deals with so serious an issue as global terrorism and trust among allies, contains some extraordinarily big-boned action scenes and features a major star who reportedly put on fifty pounds for his role, “Body of Lies” feels curiously lightweight. After seeing it one might reasonably conclude that it should have been titled “Bundle of Fibs.”

Leonardo DiCaprio stars as Roger Ferris, a canny, risk-taking CIA operative on the ground in the Middle East who’s the darling of the agency’s head for that explosive area of the world, paunchy, arrogantly aggressive Ed Hoffman (Russell Crowe). They’re intent on tracking down Al-Saleem (Alon Aboutboul), the shadowy leader of an extremely active al-Quaeda offshoot that’s undertaken attacks in Europe and threatens to expand them into America. But after the cooperative relationship he’s studiously built up with slick, savvy Hani Salaam (Mark Strong), head of Jordanian intelligence, is destroyed by Hoffman’s inept attempt to circumvent the two men’s patient watching of an Amman safe house, Ferris comes up with an ingenious plot to set up, clandestinely even within the CIA, a phony terror outfit that will force Al-Saleem into the open to engage with its supposed head, an unwitting architect named Omar Sadiki (Ali Suliman).

That’s a scheme worthy of Hitchcock—it’s like the “non-existent agent” MacGuffin of “North by Northwest” raised to an institutional level—and its intricacies, particularly those involving Sadiki and British computer whiz (Simon McBurney), who actually implements the plot, are genuinely enjoyable to watch. Unfortunately, William Monaghan’s script doesn’t take that part of the plot far enough; instead it drops the whole thing abruptly in favor of the script’s worst thread—a romance between Ferris and Aisha (Golshifteh Farahani), a sweet Jordanian nurse, that doesn’t ring true for an instant but becomes the catalyst for an act of supreme self-sacrifice on the agent’s part. The change gives DiCaprio the opportunity for a big dramatic moment as he faces off against his quarry, and—even better—it allows for a “surprise” ending involving the lesson taught Ferris by Hani about the importance of having assets on the ground that you can depend on. But that doesn’t redeem the decision to alter the narrative line.

The twist does, however, bring up the picture’s second major strength—the character of Salaam, played with a perfect combination of sophisticated poise and hard-nosed pragmatism by Strong. He’s easily the most fascinating person in the picture—he might have fit snugly into “Casablanca”—and it’s a pity there’s not more of him. By contrast DiCaprio does the same intense, craggy-spindly antihero with a conscience that he did in “Blood Diamond.” It’s good that he realizes he’s not a right choice for a conventional action lead, but thus far his attempt to shade that role into something more complex hasn’t fared very well. As for Crowe, he coasts by on the added poundage and his patented roguish charm, throwing his weight around and tossing off cynical one-liners. But you get the feeling that a fat suit and some character development would have been a better fit. (It’s also unfortunate that he delivers much of his dialogue on a cell-phone, impeding real character interaction.) Suliman and Aboutboul are fine as the contrasted extremists, but the only member of the supporting cast that adds any real punch is McBurney, who obviously relishes the part of the quirky hacker extraordinaire.

“Body of Lies” is very well made, with director Ridley Scott showing off his dexterity in the staging of the big action moments that are periodically dropped into the plot, even if they sometimes come across more as digressions than as integral elements of the narrative. (He’s helped considerably in this by Pietro Scalia’s sharp editing.) Alexander Witt’s widescreen cinematography is also top-notch, and Marc Streitenfeld’s score complements the images well enough.

But while it’s good that filmmakers should want to focus on the current international situation in their pictures, thus far they’ve either used it to drearily didactic effect (see “Rendition”) or as an excuse for Hollywood action pizzazz (see “The Kingdom”). “Body of Lies” favors the latter category, though it has elements of the former in its implicit critique of the smug arrogance of American officialdom. By combining the two it escapes neither the slick histrionics of a typical studio blockbuster nor the clumsiness that afflicts movies with political messages—sharing the worst of both cinematic worlds.