Oliver Stone is the last person one would think of to direct a straightforward survival movie about the World Trade Center attack that is free of post-9/11 politics and full of religious empathy. Yet that’s exactly what the rabble-rousing director of “JFK,” the biggest government conspiracy film ever, has done. Whomever you think is responsible for the attacks of that infamous day, it is impossible to deny the powerful emotion in Stone’s new movie, titled simply “World Trade Center.”

By the very nature of the true story it is based on, the drama peaks early in the film, as Port Authority Sgt. John McLoughlin (a fittingly subdued Nicolas Cage) leads a team of “first responder” police officers into the buildings after planes hit both towers. Stone sticks with the officers, showing us terrifying moments from their point of view only. Once they reach the buildings, the men aren’t even sure whether the second tower has been hit or not. Seeing through their eyes is a powerful device, one that resonates further with the disturbingly real re-creation of utter confusion on the Manhattan city streets surrounding the tragedy.

It’s all there– the white sheets of paper floating down from the skies, people covered in blood and layers of ash from exploded concrete. Unfortunately, there is also a CGI-shot of a person jumping from the building that takes you right out of the moment, if only briefly. The policemen take it in, eyes open saucer-wide in disbelief, getting conflicting reports from relatives on cell phones during their fateful bus ride down to the site to help evacuate the buildings. Once McLoughlin and his frightened but determined crew are inside the concourse, the unthinkable happens. The first tower falls, and they run for cover in the elevator shaft. The screen goes black.

Sound effects and light (or lack thereof) are used to great effect in “World Trade Center.” As McLoughlin lies trapped under slabs of concrete, he can hear Officer Will Jimeno (Michael Peña), the other surviving member of his team. Jimeno is pinned down as well, but can see a single shaft of light cutting through the darkness of the rubble around them. As the men lie helpless beneath twisted metal and immovable slabs of concrete and begin to ponder their situation, the second building groans and quakes.

Stone shoots these scenes in close-up of Cage and Peña’s faces to enhance the claustrophobia, as if the covering darkness were not enough. The scenes of the two men alone in the remains of the tower are painfully real. Frequently, the film cuts to a shot of what Jimeno can see. The light seems as distant and impossible as their chances of making it out. Another terrifying scene occurs soon when the second tower collapses, and the officers can do nothing but lie prone and pray to God for survival. The cold, dark aura of death looms over the men, and just as their world gets quiet, we are whisked to the bewildered rush of the outside world.

As “World Trade Center” introduces the families of the officers, the film becomes a less visceral movie than the other 9/11 movie released earlier this year, “United 93.” Mario Bello and Maggie Gyllenhaal are good in roles as the trapped policemen’s wives, and the shock of this unknown terror hitting on a personal level is convincing. But the mere idea of the grieving family makes it difficult to avoid the standard Hollywood sentimentality that threatens to sink this movie every so often.

There are troublesome flashbacks from both the men and their wives to happy times, lovingly shot with all the soft-light and warm embrace of a Fabio commercial. One of the few moments of levity for the officers comes when McLoughlin mentions that his wife will be pissed he never finished making the kitchen cabinets, but the laughs this creates are completely undermined by a schlocky, staged moment where his wife remembers him patiently teaching his son how to use a saw. He looks up to see her there, and they exchange that shared smile that is supposed to mean so much more, knowing what we know now.

Stone’s one concession to rhetoric surrounding the attacks’ motives and aftermath come in the form of David Karnes (Michael Shannon), an accountant from Connecticut who announces that the “country is at war,” and heads to New York wearing his Marines camouflage. Later at the scene, he utters some faux-poetic nonsense like “God made a curtain with the smoke to shield us from what we’re not ready to see,” and is promptly called a “nutjob” by another rescuer, just out of earshot.

What does it say that Karnes is one of the heroes of “World Trade Center”? Shannon plays him like Travis Bickle from “Taxi Driver.” His visit to the church before leaving home, and his later comments to other rescuers show that he is obviously religious. After a late movie comment about “needing some good men to avenge this,” the closing credits tell us that Karnes re-enlisted and served two tours of duty in Iraq. Is Stone linking the attacks to our current war in Iraq, despite all the contrary proof? Or is he merely laying out a fuller picture of what one man thought was necessary? Either way, it’s out of place in a movie that succeeds when it sticks to the humanity at the core of its tragedy.

Stone does conjure up haunting images that speak volumes about 9/11. More of these and less of the standard Hollywood syrup would have made a more consistent movie. An empty residential street is lit by the blue light coming from all the television sets in the houses. The camera rises up from the island with the smoke, and soon we are in outer space, looking down at the world through a satellite. The constant chatter of 24-7 broadcasting, still trying to process the news, litters the background of every scene away from the site itself. These are moments that stick with the viewer far after leaving the theater.

Back with the officers, the movie also has solid footing. Balls of fire careen around the enclosed pockets of air underneath the destruction. The fact that McLoughlin and Jimeno were barely acquaintances before the disaster gives them a lot to ponder as they get to know each other in the ugliest of circumstances. As emergency responders, they also know procedure, and that a true rescue will be next to impossible. These situations only heighten the desperate feeling and sympathetic dialogue between them.

It is during tragedies that real humanity and the innate goodness of people can come out. Sometimes this works to make the family scenes more convincing, and sometimes it the code of undying acceptance of others that becomes trying. “World Trade Center” wisely does not try to be the be-all end-all on the subject, and when it sticks to the first-person account of its survivors, it is at its most riveting.