Screenwriter Mark Boal and director Kathryn Bigelow were talking about their new movie, “Zero Dark Thirty,” and they were at a loss for words for what genre it belongs to. “Interpretive journalism?” Yuck.

“Docu-drama,” Boal suggested.

“That term is so reductive,” Bigelow countered.

“But in a sense, so is taking a urinal and saying, ‘This is art,’ ” he said.

“That’s ‘found art,’ ” Bigelow replied, casting her vote for the term “reported film.”

“ ‘Reported film’ is like ‘found art’ to me,” she said definitively. “The event happens, then it’s reported on, and then there’s an imagistic version of that reportage.”

“Zero Dark Thirty,” which opens in limited release next week, hasn’t even hit theaters and already it’s touched a nerve, largely because it occupies such a strange new space in the cultural sphere. In many ways the film, about the 10-year manhunt for Osama bin Laden after the attacks of Sept. 11, 2001, hews to the classical lines of a tense procedural, as a CIA analyst, played by Jessica Chastain, systematically puts together a string of leads that finally convince her the al-Qaeda leader is living in a compound in Abbottabad, Pakistan.

But “Zero Dark Thirty” wasn’t created in the conventional way, whereby filmmakers option a series of articles or a book about the event and then dramatize it for the screen. Instead Boal, a former embedded journalist who wrote the Iraq war movie “In the Valley of Elah” and won an Oscar for Bigelow’s “The Hurt Locker,” did his own reporting for “Zero Dark Thirty,” interviewing military and intelligence officials and operatives with intimate knowledge of the operations that resulted in bin Laden’s death in May 2011.

Because of its unconventional provenance, “Zero Dark Thirty” is arriving on the scene earlier than most feature-film accounts of recent history, subverting the usual rituals by which consensus is created, by journalists, politicians and pundits, and eventually by historians and purveyors of popular culture.

The upending of the opinion-making hierarchy has sent its denizens into a swivet. When he got wind of the project, House Homeland Security Committee chief Peter T. King (R-N.Y.) called for investigations into Boal’s access to classified information, expressing suspicion that “Zero Dark Thirty” would be a thinly veiled endorsement of President Obama in an election year. Obama, it turns out, is barely mentioned in the film, which has no obvious partisan ax to grind. But now Boal and Bigelow are under scrutiny for their depiction of torture, which some observers think is shown as yielding crucial, high-value information in bin Laden’s eventual apprehension. (The film begins with a graphic scene of a prisoner being waterboarded, an episode that doesn’t yield actionable intelligence directly but possibly weakens him enough to be manipulated later.)

As “Zero Dark Thirty” has begun to be screened in previews, it’s become something of a policy proxy, a vehicle for debate about Bush-era detainee programs, “enhanced interrogation” techniques and black sites that were ignored or never fully entertained by many Americans at the time. As Boal and Bigelow gather critics’ plaudits and awards (“Zero Dark Thirty” earned four Golden Globe nominations Thursday, including best film), the movie itself has entered a fascinating parallel conversation — part food fight for cable-news channels desperate for post-election fodder, part valuable (if belated) civic debate.

“So . . . @annhornaday making Zero Dark Thirty her #1 movie of the year makes her support torture and overall evil,” read a message that appeared on my Twitter feed this week, while my e-mail inbox filled with offers to interview think-tankers and other experts on torture (who haven’t seen the movie). On the MSNBC show “Hardball,” host Chris Matthews asked New York film critic David Edelstein whether terrorism can be defeated by “playing by gentlemanly rules.” Edelstein hesitated. “You’re asking a film critic?” he inquired incredulously.

Well, yes. With “Zero Dark Thirty,” a medium that has always occupied a liminal space — between art and entertainment, realism and spectacle, history and myth — has been pushed into yet one more indeterminate category, straddling journalism and drama. And it’s asking viewers to develop a new set of standards by which to judge and process what’s on-screen — not just in terms of aesthetic, moral and entertainment values, but as a means of processing events we haven’t fully come to terms with, offering perhaps the first unifying narrative of a deeply contentious period.

“What are the cultural criteria that get applied to this?” Boal asked last week in New York, where he joined Bigelow for a lunchtime interview. “You know how to evaluate a book, if it’s ‘The Looming Tower’ or ‘The Green Zone.’ There’s this whole set of norms you can walk [them] through. And you know how to evaluate an article.”

For his part, he said, he wants “Zero Dark Thirty” first and foremost to be evaluated as a movie. “Hopefully you view the work as what’s on the screen. Then you go outside and see how it lines up with the rest of the world. But it should start with what the work creates within you, the emotional, intellectual, moral experience.”

If he wants “Zero Dark Thirty” to be judged simply as a movie, then why did Boal go to the trouble to do so much original reporting? ”Because it’s new and it’s cool and it’s interesting,” he said simply.

For her part, Bigelow — who won best picture and best director Oscars two years ago for “The Hurt Locker,” about a bomb technician in Iraq — “Zero Dark Thirty” provided her an opportunity to engage in the kind of visceral, immersive, action-driven filmmaking she’s spent a career refining, often within the context of mostly male subcultures. The facts that Boal amassed regarding the bin Laden mission, she said, created “longitudinal and latitudinal guidelines” that she was “thrilled” to work with.

“You’re working within these parameters that are kind of freeing and exciting,” she said, “because you're trying to bring something to life to the best of your ability and make it live and breathe and feel credible.”

Much like “The Hurt Locker,” “Zero Dark Thirty” puts viewers right into the action, in this case a dizzying needle-in-a-haystack search for the courier who led the CIA to bin Laden, and later the SEAL raid, which is reenacted in virtually real time. But rather than engaging in we-got-him triumphalism, Bigelow allows for ambiguity, with conflicting emotions playing out on the faces of Chastain and co-star Jason Clarke, who plays an agency interrogator.

The torture scenes, while ugly and graphic, aren’t presented in neat, ends-justify-means terms. It’s the day-to-day tradecraft that’s shown to be more important in the intelligence hunt, as CIA operatives use deception, misdirection and resources to pursue and woo their leads. (Perhaps the most crucial piece of information leading Chastain’s character to bin Laden is a name that a colleague finds buried in old files; a crucial telephone number is obtained by buying a Lamborghini for a source.) If “Zero Dark Thirty” justifies anything, it’s not torture but data mining, which might be sexy enough for “Moneyball” but not for “Hardball.”

If “Zero Dark Thirty” makes an editorial statement, Boal and Bigelow say, it’s in an operative’s line about “the big breaks and the little people who make them happen.” In many ways, they’re paying tribute to the kind of career officials and government bureaucrats that are so often ridiculed and scorned outside Washington. Like “Lincoln,” “Zero Dark Thirty” celebrates process, professionalism and continuity of government that transcends partisan bickering and policy changes.

“Bin Laden wasn’t killed by superheroes,” Boal said. “These are people doing their job, and in a sense that’s extraordinary and in a sense it’s not.”

With luck, when audiences finally get to see “Zero Dark Thirty,” that nuance won’t be lost on them — even as they become swept up in the film’s taut suspense (especially in the final 30 minutes). Rather than a simplistic, torture-good, terrorists-bad argument, they’ll find an absorbing, richly textured portrayal of a pivotal chapter of American life, one that’s not just clarifying but cathartic.

Is it problematic that, on the way to condensing a secret 10-year history into a 21 / 2-hour film, “Zero Dark Thirty” takes some liberties with characters, timing and particular events? Will American viewers emerge feeling more ambivalent than certain about everything done on their behalf during the Bush administration and beyond? Are we willing — at the box office and through repeated viewing — to endorse “Zero Dark Thirty” as a metonym for the war on terror, the same way we’ve accepted “All the President’s Men” as a symbolic catch-all for Watergate, which was a much larger and more complex episode than two dogged reporters bringing down a president?

We’d better be. In an era when legacy media are on the ropes and genuine investigative reporting is becoming increasingly rare, journalism will surely keep migrating into other popular forms, creating a new audience of citizen-spectators. At least Boal hopes so: Earlier this week he announced plans to form Page One Productions, through which he’ll work with reporters to create TV and feature films based on their stories.

“If news can be entertainment, which it is on certain cable channels, why can’t it be a two-way street?” he asked rhetorically when we met. “I can tell you that if movies don’t do it, video games are certainly going to.” Coming soon to a theater near you: “Unmanned Drone Strikes: The Movie.” Grab some popcorn and let another argument begin.