If you want to know how seriously to take 2 Guns, just look at Mark Wahlberg’s face after he and Denzel Washington are forced to hop into the dusty bed of a pickup truck and cross the border from Mexico to Texas. The trip is meant to be a punishment inflicted by an exasperated drug lord (Edward James Olmos). They’ve stolen millions. He wants the money. They have to return it or he’ll kill a sexy hostage. Wahlberg and Washington trudge across a river along with some unspecified miserable Mexicans, and once they’ve climbed from the water, rather than look at Washington and say, “I don’t know how these guys do it” or “Immigration reform!” or something, Wahlberg goes in the opposite direction. He smiles.

It’s the smile some people have after they leave a massage or finish waxing their car. It’s the smile of an actor who’s reclining on a movie-star beach towel. Wahlberg all but walks around the film with a paper umbrella behind one of his ears. You rarely get to see a pair of stars mired in this much danger but playing the whole thing as if they were on vacation. I don’t respect the movie’s easy cynicism about drugs and crime and government corruption, but I do respect its stars’ kind of “let’s not give a damn.”

2 Guns is based on a comic book by Steven Grant and immediately distinguishes itself from most of the season’s Hollywood films by having two stars near their most watchable and by operating according to a smartish, tightish script (by Blake Masters). Washington and Wahlberg play two men — Bobby Trench and Marcus Stigman — who aren’t who they tell each other they are and pretend to be crooks in order to bring down Olmos’s character; but, of course, there’s a bigger bad guy, and he doesn’t live in Mexico. Thematically, the film creates a buddy movie out of unstable moral and bureaucratic plate tectonics. These two guys are stuck with each other because they’re the least untrustworthy people they can find, and the vacillating suspicion gives both actors something to play.

Most of the movie happens in Southwest sunlight. There’s pleasure to be had in that and the jazzed-out way Washington saunters in it. He’s best when he’s in a fedora and sunglasses, when a movie doesn’t need him to be decent, just to be good. He’s all confidence here. He’s seen the script. He knows who loses, and it’s not him. The same goes for Wahlberg, who’s not the star Washington is — he has to work a little harder at worklessness (as he did to keep up with and eventually surpass Will Ferrell in The Other Guys). But when he has material that lets him explore the vast space between moron and mastermind, he keeps surprising you. This is another Wahlberg part where no one’s quite sure how much of a simpleton his character is supposed to be. Wahlberg just plays the cockiness and the physique, the little guy to Washington’s big man.

The script gives them some fine squabbling. When Bobby drops in at Marcus’s apartment, Marcus expresses some distrust. He couldn’t not say he smells a rat, and Bobby, in Washington’s glorious Mount Vernon cadence, asks him to press on: “Let it be said.” The gist of that relationship is not unlike a Midnight Run, a cop show from the 1980s, or a romantic caper film like Charade, except here they’re emphasizing the “man” in romantic and the betrayal gladly goes both ways. But the movie’s director, Baltasar Kormákur, keeps conflating that gladness with glibness. For instance, Marcus shooting chickens buried up to their heads early on is supposed to be comically equal to later telling Olmos that he looks like a Mexican Albert Einstein (which isn’t false).

There’s more than adequate support from Paula Patton as a lissome DEA agent, James Marsden as a crooked Navy commander, and a mean ol’ Bill Paxton, who drawls in an accent that’s like how the staircase in Gone With the Wind might talk. Meanwhile, Olmos remains the kind of actor who can take a stupid stereotype and seduce you into wanting to see an entire miniseries built around him. He actually achieves goony menace because he doesn’t appear to believe he’s playing a cartoon. But that’s what the movie boils down to. Washington and Wahlberg have a good time robbing banks and blowing up buildings and barreling through military security checkpoints and double-crossing people and shooting each other because none of it really means anything.

The violence and politics here are cheap. Kormákur insists on that. 2 Guns is actually his third U.S. movie outside his native Iceland, and it’s the first to oil the surface of a thriller for the purposes of hilarity. His previous movie was also with Wahlberg — the underrated Contraband. When Wahlberg wrapped cash redundantly across his stomach, Kormákur was doing sniveling symbolism. This time he snows money down on his gun-shooting stars. Hollywood doesn’t need a semiologist to translate. This guy is pre-bragging.