“Savages” begins with a video recording of several frightened captives in a dimly-lit warehouse. The camera pans from face to whimpering face as a man in heavy boots lumbers slowly past, and a chainsaw revs ominously to life.

This opening segment lets us know right away what we’re in for—a tense and violent journey into the savage world of the Mexican drug wars, where beheadings are as commonplace as handshakes. It also creates instant contrast with the following scene, in which waves roll up the sandy shores of southern California, and a blonde narrator serenely warns us that just because she’s telling us this story doesn’t mean she’s alive at the end of it. 

The story follows drug dealers Ben (Aaron Johnson) and Chon (Taylor Kitsch), who cultivate some of the finest marijuana known to humanity. Ben is a botanist and philanthropist who, when he’s not developing a new strain of outrageously potent herb, is launching humanitarian projects in Africa or Asia. Chon is a military veteran who fought in Iraq and Afghanistan and now serves as Ben’s stone-cold enforcer. But their operation is mostly peaceful, and, although the two are perfect opposites, they’re also somehow the best of pals.

They’re such great friends, in fact, that they openly share the affections of Ophelia (Blake Lively), their mutual lover. The three of them live in a beach paradise of their own creation, with Ben handling the drug trade, Chon strong-arming uncooperative clients, and crooked DEA agent Dennis (John Travolta) keeping the law off their tails.

But as their business grows and their reputation spreads, Ben and Chon draw the unwanted attention of a dangerous Mexican drug cartel led by mysterious overlord Elena (Salma Hayek). When the pair refuse to partner with her, she sends her vicious right-hand thug Lado (Benicio Del Toro) to kidnap Ophelia and force them to cooperate. Desperate to get her back, Ben and Chon begin scheming an unlikely rescue plan.

The movie works largely because of its numerous clashing dichotomies: the hippy idealist and the war-hardened realist, the sunny beaches and the seedy streets, the light humor and the cringing suspense. It’s remarkable how director Oliver Stone can have us wincing one moment and chuckling the next, keeping us captivated all the while.

At first blush, it’s a bit tough to swallow that the top villain here is portrayed by the beautiful and distinctly un-scary Salma Hayek. Are we really expected to believe that a notoriously brutal gang of rapists and murderers is led by Kitty Softpaws? But Hayek pulls it off, creating a character whose icy demeanor belies her own conflicts and weaknesses. 

Whatever physical menace Hayek lacks is compensated for by Del Toro, whose sadistic grin is at once chilling and magnetic. Whether eating a steak or brandishing a bullwhip, he oozes with criminal cruelty, and yet even he delivers a laugh or two.

The young leads are highly competent, as well. Watching Aaron Johnson confidently strut across the screen, it’s hard to believe this is the same awkward adolescent who starred as Kick-Ass just a couple of years ago. Kitsch and Lively both cut their teeth on teen-friendly TV shows, the former in “Friday Night Lights” and the latter in “Gossip Girl,” but they make a smooth transition to this mature dramatic thriller.

Travolta is comically sleazy as the corrupt DEA goon, making deals on all sides to protect his own butt. But his character, too, evokes some degree of sympathy and likability. The end result is that the audience roots for just about everybody to survive, which adds to the tension when it seems certain not all of them will.

The movie’s few action sequences unfold like Desert Storm operations, complete with ex-Navy Seals armed with assault rifles and rocket launchers. There is some graphic violence, including a seat-squirming torture scene and some gruesome executions.

“Savages” is not without flaws, though, and it’s difficult to understand what the filmmakers were thinking when they devised the climax. It’s as if they couldn’t choose between two proposed endings and so decided to use them both, and neither is quite satisfactory. Perhaps that echoes the novel by Don Winslow, who also co-wrote the screenplay.  

If you’ve got a stomach for violence, this film has more to offer than the superhero fare burning up the box office. It’s got a great soundtrack, too, featuring everyone from M. Ward to Bob Dylan to Peter Tosh (especially appropriate for the copious weed-smoking).

Stone barely touches the political underpinnings of the cross-border drug wars. His message here is more about the strength of personal bonds—whether between friends, lovers or family members—and the sacrifices they inspire. It’s some of Stone’s best work since the early ’90s, and it will make anyone think twice before entering the drug biz.