On 12 August 2022, as Salman Rushdie was about to launch into a lecture on the importance of protecting writers from harm at New York’s Chautauqua Institution, a man in a black mask rushed the stage with a knife. To the horror of the packed amphitheater, the man stabbed the Indian-born British-American author – once the subject of an infamous fatwa from the leader of Iran in the 1980s – 15 times in the face, neck and torso, before members of the audience rushed the stage and disarmed him. Rushdie survived, narrowly; the stabbing left him on a ventilator, severed tendons in his left hand, and cost him his right eye.

A full recreation of that attack from Rushdie’s perspective — 27 seconds of struggle, the mysterious man’s face, several sickening punches of blade — opens a new documentary on Rushdie’s recovery and resilience, which drew a standing ovation at the Sundance film festival. Knife: The Attempted Murder of Salman Rushdie, directed by Alex Gibney and based on Rushdie’s memoir of the same name, is unsparing on the devastating results of the stabbing: in never-before-seen footage recorded by the author’s wife, Rachel Eliza Griffiths, Rushdie appears gruesomely disfigured — his skin discolored, his entire abdomen bisected by stitches, his swollen neck held together by stitches, his eye indescribably mangled. His first coherent thought after regaining consciousness, he recalls in the film, was simply: “We need to document this.”

The motivation to record an unvarnished account of Rushdie’s recovery, nurse-administered cleanings and all, was partly a coping mechanism. “When we were in the trauma ward, it wasn’t like ‘let’s make a film,’” Griffiths, a poet and author, said at the film’s sold-out premiere in Park City, Utah. “It was ‘what’s going to happen to us? How did this happen to us? And here we are, in this moment.’”

But it was also a larger act of defiance against political violence. Though the documentary features Rushdie as both subject and narrator, “it’s not about me,” the 78-year-old writer told an enthusiastic Sundance crowd, several of whom were in tears. “I think it’s about a larger thing, of which this is an example. Violence is that thing. Violence unleashed by the unscrupulous, using the ignorant, to attack culture.”

“For the authoritarian, culture is the enemy,” he added. “The uncultured and ignorant and tyrannical don’t like it. And they take steps against it, which we see every day.”

Gibney, whose prior films have explored such tricky subjects as Scientology, Elizabeth Holmes and the Trump administration’s Covid reponse, uses the attack as a launchpad into the future — Rushdie and Griffiths’s intimacy as its own miraculous resistance — and into the past, retracing the novelist’s early life in secular Muslim family in India, and later in London, where his writing was met with resistance from those who deemed as antithetical to Islam.

The 1988 publication of his novel The Satanic Verses, the title of which referred to a group of Quranic verses related to three Meccan goddesses, sparked backlash from many Muslims who deemed it blasphemy; Ayatollah Khomeini’s fatwa calling for Rushdie’s death, as well as death for anyone who published him, took it viral. The film includes numerous clips of protesters burning Rushdie’s effigy in London, New York, Bombay and beyond, with images that eerily foreshadow Rushdie’s injuries over three decades later; numerous news clips, too, of people around the world — men and women, young and old — stating clearly for news anchors that they would kill Rushdie themselves, if given the opportunity.

Rushdie, who spent nearly a decade in hiding under the protection of UK police, said he was reluctant to revisit that era of his life, even as it belatedly inspired a 24-year-old man from New Jersey, who was not even alive for the fatwa, to stab him 30 years later. But he soon realized “if you don’t understand what happened then, you don’t understand what’s happening now”.

Gibney, too, connected the widespread protests against Rushdie’s book to “our present moment” during a post-screening Q&A that obliquely referenced the current unrest in Minneapolis, Minnesota, where ICE agents shot and killed a 37-year-old US citizen the day prior. The death threats that drove Rushdie into hiding, Gibney said, echo today in “how violence unleashed by an irresponsible political leader could spread out of control”.

Gibney also saw parallels in Rushdie’s recovery from the 2022 attack, during which, as Griffiths’s footage reveals, he never lost his “righteousness and principles” — or his sense of humor. (Of his assailant’s jailhouse interview with the New York Post, in which he said he was surprised Rushdie survived, the author had this to say: “Thank you! That demonstrates intent.”) Against “the growing momentum of authoritarian rule”, Gibney said, “it’s important that we continue to embrace our humanity, to love each other, and to continue to achieve that kind of intimacy that’s so important to us as human beings, even as we face this larger political challenge”.

The documentary returns, in its final minutes, to the attack that began it — this time from the third-party perspective, as the conference cameras captured the bloody attack in its entirety. The grisly footage shows nearly every stab of the knife, as well as the many strangers who tackled the man and saved Rushdie’s life. That day, he experienced, “almost simultaneously, the worst side of human nature — violence, led by ignorance, induced by the irresponsible — and on the other hand, the best side of human nature, because the first people who saved my life were the audience”, he told the Sundance crowd.

“Here are the people rushing to defend me against an ideologically driven man with a knife,” he added. “And yet they all agreed to do that, to risk themselves in order to save me. We are that, too.”

• Knife: The Attempted Murder of Salman Rushdie is screening at the Sundance film festival and will be released at a later date