Jon Stewart is tired.

Nursing an iced coffee in a Washington hotel room, where the Comedy Central host recently entertained interviews on the subject of his filmmaking debut, “Rosewater,” Stewart doesn’t hesitate before answering a question about what his plans might be after his contract with “The Daily Show” expires next fall: “A nap.”

Maybe he needs one. Reminded of the last time that this newspaper profiled him, in 1995, Stewart groans. Reflecting on the unforgiving nature of aging in the media spotlight, Stewart, who turns 52 this month, cracks wise: “You just watch yourself slowly die. In ’95 it was probably: black hair, smokin’, drinkin’. And now it’s: slumped over, don’t drink any more, don’t smoke, gray hair.”

Sidestepping any firm commitments about the future, the longtime host, executive producer and writer for the popular “fake news” show says he’s just waiting for a “moment’s respite” in order to get some clarity on the decision, without being influenced by such extraneous factors as his own “exhaustion.”

Stewart took a three-month hiatus from the show last year to film “Rosewater.” Shot in a working Jordanian prison, where the temperature routinely climbed to 100 degrees, the Iran-set drama is based on “Then They Came for Me,” a memoir by Canadian Iranian journalist and filmmaker Maziar Bahari, who was imprisoned while covering that country’s 2009 presidential election for Newsweek. When asked to characterize Stewart, with whom Bahari collaborated throughout the screenwriting process, and then later, as an on-set consultant, Bahari says his biggest revelation was not how serious the funnyman can be off camera but what a workaholic he is.

“Jon would sometimes meet me at 7 a.m. for breakfast, before going in to ‘The Daily Show’s’ offices at 9 or 9:30,” Bahari says. “Then he would go home at night and write the script. When you meet Jon and you get to hang out with him for a few days, you get to realize that he’s really a genius in the way that he absorbs information and can analyze it quickly.”

The story behind the two men’s collaboration is a doozy. In the midst of Bahari’s 118-day ordeal, during which he was regularly interrogated and beaten, it came to light that his anonymous Iranian government interrogator — nicknamed “Mr. Rosewater,” for his cologne — seemed to believe that Bahari was a Western spy, based in part on a satirical “Daily Show” video that Bahari had appeared in before his detention.

As a guest on “The Daily Show” after his release, Bahari made it clear that he didn’t blame the host for his captivity. “I could be on ‘Sesame Street,’ and they would accuse Elmo of sedition,” he joked. The two men became friends, and a conversation about Stewart producing a film adaptation of Bahari’s book led to typical Hollywood roadblocks: scheduling conflicts and not enough money to hire the writers or directors they wanted.

“After about a year and a half of really not getting anywhere,” Stewart recalls, “I said I felt that I had a clear enough vision of what this could be in a narrative sense to just go off and write it as quick as possible, so that we had a document to work off of, to expedite it. From there, you begin to become territorial. As the project develops, you begin to think, ‘God, I don’t know if I want to pass this to someone.’ ”

Stewart wasn’t entirely convinced he should — or could — direct the thing, but he didn’t let that stand in his way. “Oh, I’m still not convinced,” he says. “If you wait to be convinced that you can do something, you’ll never do anything. People always ask me, ‘How do I become a comedian?’ And I always say, ‘Well, I think one thing you should do is get on stage and tell jokes.’ ”

The filmmaking process did require a slower metabolism than Stewart is used to. “I’m accustomed to fast food,” he explains. “You come up to the drive-through and go, ‘Gimme three jokes on George W. Bush . . . and a pun!’ ” Still, he believes that making a movie is not entirely alien to doing stand-up or a half-hour TV show or a book. It’s just another way, he says, of breaking down a narrative. “It wasn’t as though Maziar had said, ‘What if you and I did a folk album of Iranian protest songs, with you on lead vocals?’ ”

Based on the New York Times best-selling memoir “Then They Came for Me: A Family’s Story of Love, Captivity, and Survival,” written by the BBC journalist Maziar Bahari, "Rosewater" follows the Tehran-born Bahari, a broadcast journalist who was arrested by the Iranian government. Last year, “Daily Show” host Jon Stewart took a break so he could write and direct “Rosewater.” (Open Road Films)

For Stewart, the appeal of Bahari’s story was its universality. It’s about more, he says, than simply “one man in one eccentric authoritarian regime. This is something that is being done to people throughout the world and is necessary to do to people when you want to fight them. If you want to bomb people, you have to try to convince yourself that they’re not people.”

The humanist perspective extended to the film’s villain as well. Stewart and Bahari both describe Rosewater, who is played in the film by the Danish actor Kim Bodnia, as less monster than stressed civil servant — one whose office happens to be Tehran’s notorious Evin Prison and whose workload consists of political prisoners. “You have to look at it within the context of, now thousands of people are being arrested,” Stewart says, referring to Iran’s post-election crackdown on dissent. “Evin Prison is busy. We may look at it as the ‘Green Movement’ revolution, but these guys look at it as overtime. This is a bureaucracy. This is a bureaucracy where the widget that they make is torture.”

With that in mind, Stewart says he couldn’t resist inserting a joke into the script that isn’t in Bahari’s book. When Rosewater forces Bahari to call his wife, Paola, in an effort to get her to stop “talking s---” about Iran in public, Bahari’s torturer hands him the phone, saying, “You’ve got to dial 9 to get out.” “When that joke lands,” says Stewart, “I always feel really wonderful.” (According to Bahari, the laugh line isn’t far from the truth. Rosewater, he says, placed calls using a scratch-card “to get the cheaper minutes.”)

Despite such surreal, even comical moments, “Rosewater” is neither farce nor satire. If much of the film’s humor derives, ironically, from Rosewater’s humorlessness — e.g., his inability to comprehend that the incriminating “Daily Show” clip was a joke — Stewart is emphatic that the line between satire and truth should never be deliberately blurred.

“I think you should know when something’s satire,” he says. Stewart laments the fact that certain journalists seem to have lost sight of that, adopting the means of satire — hyperbole and caricature — for their own ends. “What may seem surgical in a satirical sense may seem a bludgeon in a journalistic sense,” he says.

Case in point: What Stewart calls the “polemicists” (read: Fox News pundits) hawking increasingly inflammatory headlines: “First it’s ‘Liberals are wrong,’ ” Stewart says. “Then it’s ‘Liberals are fascists.’ Then it’s ‘Liberals want to f--- your dead grandparents.’ They have to continue to push that to grab eyeballs.”

Stewart harbors no illusions about his own role in the process, acknowledging that “The Daily Show” is widely consumed, not on television, but in the form of short, viral videos, distributed via outlets such as Facebook, the Huffington Post and, ahem, The Washington Post. “The beast needs food. We’re part of that ecosystem too. We’re not separate from it. Our beast exists to get eyeballs too.”

He’s neither “depressed nor demoralized” by the proliferation of content made possible by the Internet, he says, yet attributes the reason he’s not on Twitter to the increasing banality of the chatter. At one end of the spectrum, Stewart sees “really smart, thoughtful, interesting analysis of news.” And at the other end? “It’s a link saying, ‘This picture will change the way you view monkeys.’ And then you click on it, and it’s a monkey in a hat.”

As for where “The Daily Show” falls on that continuum, Stewart admits that it’s probably at the intersection of the two extremes.

Yet he doesn’t see those goals — being funny and being responsible — as being at cross-purposes. As evidence, Stewart cites the recent controversy over a “Daily Show” segment in which several rabid Redskins fans claimed to have been ambushed when producers from the show confronted them with a group of angry Native Americans, upset about the team’s name. When that segment finally aired in September, “correspondent” Jason Jones owned up to the controversy on camera, even at the cost of the bit being less funny than it otherwise might have been.

According to Stewart, once the controversy broke, it was incumbent on the show to acknowledge it. “One of the things you learn as a stand-up is you must be cognizant of the audience and what they’re thinking,” says Stewart, who believes that the idea of responsibility isn’t anathema to humor, but, rather, an essential ingredient of it. Comedy, he argues, is more transparent than most journalism — or most government.

“What’s so interesting to me is the concern that people have for the rules of the moral universe of comedy,” he says, “but not as much concern for the moral universe of governance. I’ve never heard someone ask a leading figure, ‘Where do you draw the line?’ I hear that a lot to comedians: ‘What’s too far?’ I don't think I’ve ever heard that with a president. What’s too far? Solitary confinement? Incarceration for, you know, three-strikes-and-you’re-out drug convictions? Bombing civilians?”

If Stewart sounds less like an outraged comic — or a rabble-rousing filmmaker — than a politician, he is quick to put the kibosh on any speculation that his post-“Daily Show” career might include a run for public office.

With all his talk about transparency and the moral universe — and with a new film out championing press freedom — wouldn’t a lot of people, or at least brokenhearted progressives, vote for him?

“You don’t know that,” he says with a laugh, “except in the way that people would vote for a second-string quarterback to take over for the first-string quarterback if they are feeling frustration at their team’s goals. And then five minutes into the first quarter, after two interceptions, you’re like, ‘F--- that guy. Get him out.’ ”

Besides, Stewart insists, he doesn’t have the right “skill set” for the job. And what might that skill set be, that this restless and responsible, hyper-verbal and deeply thoughtful funnyman-turned-filmmaker lacks?

“Patience,” he answers.