Former White House chief strategist Stephen Bannon finishes a television interview in September 2018 in Rome. Bannon is the subject of a new authorized documentary premiering at the Sundance Film Festival. (Jabin Botsford/The Washington Post)

Correction: An earlier version of this article about the new Stephen K. Bannon documentary “The Brink” said that Bannon had asked about a London street’s “flip” after being told it had become populated with predominantly Muslim businesses. He had been told it had become populated predominantly Arab stores. This version has been corrected.

Stephen K. Bannon has been out of the limelight in recent months, with the focus on the government shutdown and everything else that’s happened since he left the White House in 2017.

A new Sundance documentary is here to remind that Bannon never vacated the world stage — and to offer a startling and revealing look at the work he’s been doing for the past 18 months.

Far from removing himself to a kind of book-circuit retirement taken by many former White House staffers, Bannon, it turns out, has been keeping busy. He’s been meeting with nationalist party leaders in Europe to unite them into a global web, courting billionaires to keep the money funding his efforts and designing what he freely admits is propaganda to swing voter opinion in the United States.

“What would Leni Riefenstahl do?” Bannon says at one moment in the documentary, titled “The Brink,” after he shows journalists a new pro-Trump feature film he made to influence the midterm races. “How would Leni Riefenstahl cut that scene?”

Directed by Alison Klayman, “The Brink,” which Bannon cooperated with, is a rare fly-on-the-wall look at its subject. It offers the specter of an unguarded zealot, a firebrand with his sleeves rolled up. When it makes its first-ever public screening on Wednesday at the Utah festival, followed by a commercial release from “RBG” distributor Magnolia Pictures in March, it will cast new light on one of the most polarizing figures in modern politics.

And while that light is thrown on a figure more charming and self-deprecating than his sometimes Voldemortian public image, “The Brink,” which The Washington Post was shown before the festival, doesn’t lack for provocative moments.

In the back seat of a black car while traveling in London, Bannon is told by a British staffer that a formerly Christian-heavy street has become populated with Arab stores. “When did it flip?” he replies.

Meanwhile, near the film’s beginning, he can be seen doing nothing less than assessing the engineering feats of Holocaust death camps. Birkenau, he says, was far more impressive than Auschwitz, because it was built from the ground up, as opposed to Auschwitz, which was a requisitioned Polish cavalry college. “Precision engineering to the nth degree, by Mercedes, Krupp, Hugo Boss,” he says, while recounting to the camera a visit he took to the camp to shoot the 2016 Phil Robertson documentary “Torchbearer.”

Much of the film, however, is not marked by flame-throwing comments — Bannon repeatedly denies charges of racism and anti-Semitism and says he’s not engaging in dog-whistle politics — but a more subtle exposition of his operating mode.

Klayman, a New York-based documentarian who chronicled a different type of free-speaking activist in 2012’s “Ai Weiwei: Never Sorry,” and the film’s producer, Marie Therese Guirgis, were given uncommon access to their subject.

Klayman spends more than a year with Bannon, from shortly after he left the White House in the summer of 2017 through the recent midterm elections. When he’s not campaigning for candidates like Roy Moore or holding rallies in which he talks about Trump’s import, he is often meeting with leaders of far-right parties such as UKIP and the National Rally in Europe.

The goal, he says, is to create a “convening authority for conferences ... [to] get ideas out.”

The import of those moments is not always clear to the viewer — and it wasn’t to Klayman.

“It was the kind of thing where days would end and it was, ‘What did I watch?’ Did a bunch of people just have dinner in Europe or did I just watch the Wannsee Conference?” she said in an interview, referring to the landmark 1942 Nazi gathering.

Bannon saw the movie after it was completed, Klayman said. She and Guirgis said they were not sure how he felt about it.

Reached by text, Bannon replied but would not comment on his feelings about the film.

Klayman said she, like many viewers, can debate how much significance to accord the former White House adviser. She also was sometimes unsure about whether Bannon’s ethno-nationalist pronouncements were motivated by a deep-seated racism or political expedience.

“I don’t know what’s actually in his heart. But I think you can tell a lot about who he is by who he’s willing to work with,” Klayman said, citing the National Rally in France, Fidesz in Hungary and other nativist parties in Europe.

(Bannon suggests there’s some calibration in his comments. “Hate is a motivator,” he says.)

While the verite format keeps the in-film criticism mostly muted, a number of moments seem to make the argument that Bannon’s populism is a pose.

He can be seen joking about taking a private plane from the Van Nuys Airport in Los Angeles, and there are a number of shots of him on such aircraft, flying to meetings and speaking engagements around the world. It is unclear who is funding these flights. Bannon meets with a number of very wealthy people throughout the film, including Guo Wengui, or Miles Kwok, the billionaire Chinese businessman living in the United States who has been sharply critical of the Chinese government.

“Brink” comes several months after the Toronto International Film Festival premiere of another Bannon film, Errol Morris’s “American Dharma.” That movie, which received mixed reviews, was centered on a set of interviews with its subject instead of shooting him verite-style.

“That was Stephen K. Bannon domesticated. This is him in the wild,” said Eamonn Bowles, who runs Magnolia, which also financed the film.

The movie first came about when Guirgis, a documentary producer in New York, reached out to Bannon with the possibility of a documentary about him. Guirgis had worked for Bannon in the 2000s at Wellspring Media, an indie-film company he ran that distributed a host of edgy art-house films. He turned her down the first three times but agreed on the fourth request, just a few weeks from the initial ask. He eventually signed a release relinquishing control over his appearances in the final cut. (Such releases are common when a high-level documentarian embarks on a movie about a controversial figure; Bannon had initially delayed signing it but eventually did so during production.)

Bannon has a long history with cinema, having directed numerous movies about purported Republican heroes and Democratic villains; it’s that interest that Klayman and Guirgis believe helped drive his willingness to cooperate with this movie.

Another possible factor, said Guirgis, was the prospect of cementing his brand. It was an outcome, she and Klayman said, that the pair worried about before embarking on production. But they ultimately thought the chance to expose him in action outweighed those concerns. (Both the movie itself and the inclusion of several anti-Bannon rallies, raises the timeless question of whether to shine a light on controversial public figures is to elevate them.)

Guirgis said she was motivated to make the movie by hearing perceptions that didn’t square with the person she worked with.

“To read the coverage after he joined Trump — ‘he was this genius strategist, a mastermind, Darth Vader, some kind of philosophical genius’ — it didn’t fit with what I knew,” she said. “And I thought those depictions were skewing him and emboldening him; he was turning them into currency.”

She added, “He was very smart and could make decisions quickly. But it was very seat-of-his-pants.” And, she said, a history going from the military to Wall Street to film to media to his current profession suggests a dilettantism that doesn’t fit with the political-animal image. “It seemed like there was as much coincidence to where he ended up as anything else,” she said.

In addition to featuring several self-aware and charming moments, the movie also shows him concerned about his public appearance in an unexpected way. “I didn’t look like an a‐‐hole?” he asks an aide after a media appearance.

Klayman said that while there are moments when she liked Bannon personally, she ultimately found him “kind of a con man and a stuffed shirt; a lot of what he says I don’t believe.”

She noted moments in which, asked to describe his radical philosophy of economic populism, he cited pro-business ideas that have been in the Republican Party for years, with just what she says is an added layer of anti-immigrant and — anti-Muslim sentiment.“It seemed like a real poverty of ideas,” she said.

The film does show him at more charming moments. A smile is often playing on his lips, and he can be seen either taking a shot at himself or playfully at others; if there’s a lot of meanness in his everyday life, it is not on display. But whether that blunts his policies or makes it more dangerous is a question Klayman leaves open.

Ditto whether he is, at heart, an opportunist or an ideologue.

“I can give an answer,” Klayman said. “But he’s imagining a restructuring of the global order aligning a series of global Christian white nations. Is it driven by wealth and power or by an agenda? I’m not sure the answer matters.”