Not everyone knows the story of the first U.S. combat forces in Afghanistan after 9/11. As related in the 2009 book "Horse Soldiers," a small team of 12 Green Berets — known, in officialese, as ODA (for Operational Detachment Alpha) 595, as well as by the much cooler code name Task Force Dagger — achieved a startling victory: Assisted, on the ground, by ragtag fighters loyal to an Afghan warlord and, from the sky, by U.S. bombers, the men of ODA 595 — often on horseback — helped liberate a stronghold of Taliban and al-Qaeda, Mazar-e Sharif, within a matter of weeks.

Their return to the United States was greeted with little fanfare.

While it's gratifying — and occasionally gripping — to see that story told in "12 Strong," the Jerry Bruckheimer-produced film contains few genuine surprises, at least from a cinematic standpoint. Despite solid performances by the ensemble cast, led by Chris Hemsworth as cocksure Capt. Mitch Nelson and Michael Shannon as his grumpy, retirement-ready second-in-command Chief Warrant Officer Hal Spencer, the fictionalized film relies heavily on cliche, including the kind of swaggering banter one might expect from a video game. "That's what I call a target-rich environment," cracks one member of Mitch's team, when they are informed that their tiny squad is up against more than 50,000 Taliban fighters.

Although the Americans complain that it's hard to tell who they're fighting against — even their allies treat them with suspicion — it's abundantly clear to the audience who the bad guy is. The enemy is embodied by an almost cartoonish, black-clad Taliban mullah, who, when he's not executing a weeping schoolteacher for educating girls or firing a barrage of RPGs at Mitch and his men, is peering through the red-tinted lenses of binoculars that lend him a satanic malevolence.

Make no mistake: Despite the absence of white hats — not to mention helmets — on Mitch's men, "12 Strong" is a Western, set in the mountains of Afghanistan. It isn't just the horses, which are well choreographed and sometimes thrillingly shot, often from high angles. Or the bleakly beautiful terrain, which director Nicolai Fuglsig uses to great advantage, as his camera flies over exploding ordnance. Or even the fact that the Americans operate out of a base that has been nicknamed the "Alamo," fighting against overwhelming odds (yet another trope of the cowboy movie).

But despite these and other staples of the genre, the film's macho dialogue — inflected with an unsettling gallows humor that renders the real-world gravity of the situation unserious — makes the protagonists of "12 Strong" come across as "all hat and no cattle," to use a common phrase for Western posers. "I wasn't going to let you have all the fun," says one of Mitch's men, as he joins his commander in what only seems like — but really isn't — a matter of life and death.

What the film does well is underscore the story's essential absurdity. Its heroes are dropped into a country where they don't speak the language; don't know how to ride horses (except for Mitch, who, naturally, grew up on a ranch); can't tell the enemy from their friends; and are clueless, culturally, about Muslims in general and Afghans in particular. Orders, when they make sense, seem to be issued by an inept and reckless bureaucracy: The helicopter that takes the men to Afghanistan flies at an unsafe altitude and is supplied with oxygen masks that don't work. "There are no right choices," says General Dostum (Navid Negahban), the Afghan warlord who is fighting alongside Mitch, fatalistically. "This is Afghanistan, the graveyard of empires."

Far from the rah-rah kind of war story that some may be used to, "12 Strong" is suffused with Dostum's cynicism. Although refreshing in a way, that attitude flies in the face of everything else that the movie tries to tell us: That Mitch and company are fighting to right a wrong, and that it matters. More often than not, "12 Strong" feels like a sports movie, where all the stakes rest not on matters of honor and duty, but on a single field goal.

R. At area theaters. Contains war violence and strong language throughout. 130 minutes.