"Body of Lies" is both terrifying and comforting.

It succeeds as few movies do in bringing home the frightening notion that terrorists do not intend to stop their murderous campaign until every person on Earth either converts to their way of thinking or is killed.

At the same time, it shows the impressive technology one certainly hopes is available to combat them and track them down, particularly high-resolution video from spy planes.

These conflicting ideas -- that we're both threatened and safe -- are not the film's main point, but it is the part of the movie that works best. The main point, that the people running the American response to terrorism do not understand the realities of the people actually fighting it, is weaker.

It suffers because the story trajectory is too vague; at times, the story treads water with random incidents, waiting until it is time for the climactic showdown between the CIA and the head terrorist. And when it comes, this climax is disappointing.

Leonardo DiCaprio stars as CIA agent Roger Ferris, the best and brightest field agent who can instantly size up any situation. He also understands Arabic culture, which earns him Brownie points with the Jordanian head of state security. On the other hand, he is also a murderer and a sadist, so we never quite warm up to him.

Ferris does the bidding of his bloated and comfortable supervising officer Ed Hoffman, who tends to order Ferris' dangerous missions while watching his daughter's soccer games. Hoffman is played by Russell Crowe, which means that, along with DiCaprio, the film should have some pretty decent acting.

But it is directed by Ridley Scott. In a Ridley Scott film, the actors are usually the least important part of the whole. Scott is all about the visuals, and he always will be. And as sometimes happens in his movies, here his slick visual style, kinetic camera and emphasis on style over substance mostly works to the movie's advantage.

Sometimes, though, it's just a little silly. Scott can't restrain his love of moodily wetting down the streets even in Amman, Jordan, where it rains an average of less than 11 inches a year.

The film is based on a book by David Ignatius, and perhaps the filmmakers tried to include too much of the source material because the story bogs down in the second half. Some of the scenes add nothing to the story, and the plot goes off in several hesitant directions at once. It never quite comes back together again.

Scott tries to counter this narrative fraying with lots of pretty explosions and fires and fast cars. Scenes of violence are inserted into the story like clockwork, every 15 or 20 minutes or so, with the result that Ferris gets beaten up an awful lot. He is blown up twice, bitten by dogs, hurt in a car accident, beaten and much worse.

The hardest-working guy on the set was the guy whose job it was to keep track of Ferris' ever-increasing number of scars.