I admire Peter Berg’s “Lone Survivor” on a technical level, and respect the courage and prowess of the real-life soldiers upon whom this true story is based. However, the film’s near-complete lack of characterization, coupled with its torture-porn brutality, made it an endurance test to sit through.

And that’s probably what Berg had in mind.

Like Ridley Scott’s “Black Hawk Down,” this is an ultra-realistic combat simulation that drops the viewer directly in the line of enemy fire. There’s a ‘caught-in-the-crossfire’ intensity to the violence that never lets up once the first bullet leaves its chamber.

Shattered bones are rendered in extreme close-up and shrapnel wounds are documented in near-clinical detail. We’re talking state-of-the-art carnage, created by cinematic craftsmen of undeniable skill.

It’s too bad then that we never learn much about the four main characters who suffer the worst of it. The most I could glean from the film’s brief pre-combat opening is that two of them apparently have wives and fiancés waiting for them back home. Apart from their facial hair preferences, that’s about as in-depth as they get.

Having starred in the war film “A Midnight Clear” (1992) and directed “The Kingdom” (2007) – not to mention the amusingly goofy “Battleship” (2012) – it’s obvious that Peter Berg has a deep admiration for the extraordinary sacrifices soldiers make. So it’s doubly-hard to figure out why he’d invest so little humanity in the main characters, while lavishing enormous effort to show how painfully they died. It’s clear that he wants to honor them with this movie, but I don’t understand how stripping them down to bearded mannequins in a gory shooting gallery accomplishes that. Once they come under attack, we may as well be watching videogame avatars.

The movie’s centerpiece battle lasts a full hour. I wish Berg had carved fifteen minutes from it and added them to the opening section of the film.

Where did these men grow up? Why did they join the military? Do they truly believe in what they’re fighting for? What plans do they have once their mission is over? “Lone Survivor” doesn’t bother to ask those questions, let alone answer them. Instead, we’re treated to a semi-standard ‘Band of Brothers’ philosophy and little else. I don’t know why the producers cast actors like Mark Wahlberg and Emile Hirsch and then gave them nothing to play. These are purely physical performances, the kind that could have been accomplished by any number of charismatic stuntmen.

If we learn very little about the movie’s heroes, we’re given even less info about the Afghanis in the film. In many ways, this is an old-school war movie, the kind that paints every non-American in strictly black and white terms. Some are “good guys,” most are “bad guys,” and we can tell exactly who’s who by how much they scowl. I could overlook this shallowness if even one of the “bad guys” was the slightest bit memorable. But here they’re virtually interchangeable. Investing one of them with a smidgeon of personality might have made the climax seem a bit more exciting. As it stands, the finale is the film’s weakest sequence.

Another problem is that there’s almost no context to the heroes’ mission. We’re told that they’re supposed to identify a high ranking Taliban bigwig, but then what? There’s no larger scope to their task, and very little seems at stake if they fail to complete it. Without a greater sense of risk, or some kind of global urgency, they might as well be a bunch of heavily armed backpackers who got lost behind enemy lines.

The film opens with real-life documentary footage of young recruits training in boot camp, and I have to confess, this felt more than a little exploitative to me, especially once the high-velocity, high-gore action sequences began a short while later. I’m just not sure that “Lone Survivor” is serious enough to warrant its inclusion.

And finally there are the photos of deceased soldiers shown during the end credits. Whoever decided to score this heartbreaking montage with Peter Gabriel croaking out a dirge-like version of David Bowie’s “Heroes” should have picked another song. It’s borderline ghastly.

I’m glad I saw “Lone Survivor,” but I doubt I’ll be seeing it a second time.