Last month, Lynn Novick traveled to Vietnam with her new documentary about the American war there, co-directed with Ken Burns. Novick had previously spent time in the country, gathering material for the doc, which tells the story of the war from both the American and Vietnamese perspective. On her return, she held four screenings of a condensed version of the film — one for living witnesses interviewed for the series, one for writers and critics, and two more for public audiences in Hanoi and Ho Chi Minh City, respectively. Novick was wary.

“It’s always with some trepidation that we show something that we’ve worked on to the people who lived through it, because how’s it going to jibe with what they remember and what they saw?” she says. “But it was amazing. We heard over and over again the feeling that the film was honest and realistic in depicting the true suffering and misery of the war and the complex human experience, both American and Vietnamese. Everyone we spoke to, they want this story to be told and for us to learn about their experience and for them to learn about our experience.”

Premiering Sunday on PBS, “The Vietnam War,” is drawing significant international attention — in the nation transformed by the war, but also far from Southeast Asia and the United States. It has already been licensed by 21 broadcasters in 43 countries, the most ever for a Burns film ahead of its debut. Arte in France and Germany, RTE in Ireland, and the BBC in the U.K. will all premiere the 10-hour international cut of the series within a week of the full, 18-hour U.S. version’s debut on PBS.

Releasing so close to the PBS date is, for international broadcasters, a bet that the premiere will generate buzz among documentary viewers that will carry across the world. Many broadcasters bought into the project well before the film was ready to be shown to them — a rarity in international television documentary sales.

Much of that interest came from the convergence of Burns’ brand, built on tackling enormous subjects such as jazz and baseball, with the American war in Vietnam, a relatively recent historical event that has been a bottomless well for art and popular culture.

“Nobody’s ever asked the question of how could we put our arms around everything and tell not just the American war — ‘Coming Home,’ ‘Apocalypse Now,’ ‘The Deer Hunter,’ ‘Born on the Fourth of July’ — with a Vietnamese narrative, which is going to give you a variety of points of view that no one’s ever heard, ever,” Burns says. But he and Novick were able to take on the task, “because of the unusual access we had to the country, its archives and most importantly its people.”

For the film, hours of interviews with Vietnamese civilian and military survivors of the war. When the series premieres Sunday on PBS, those survivors and everyone else in Vietnam will be able to watch. PBS is making the series available to stream online in Vietnam. The geo-blocking that prevents internet users in other countries from watching content only licensed to stream in the U.S. will be lifted for Vietnam users. The full 18 hours will be available to watch with Vietnamese subtitles.

“At numerous times people said things like, ‘We never speak about the war or we don’t really tell the truth about the war, our children don’t know about the war and how will they understand the price we paid if we don’t tell them what it was like,'” Novick says. “So to honor that testimony, it felt to us that it would be extraordinary if the film could be seen in Vietnam.”

So far, the reception has been positive. After viewing the film’s highlights, Bảo Ninh, a novelist famous in Vietnam for his writing about the war, wrote to Novick that he was “extremely impressed and satisfied with the film.” Ninh is one of numerous veterans of the war that the filmmakers interviewed.

“As a soldier in the war, whose writing is indelibly linked with it, I was deeply moved by what I saw,” he wrote. “I want to thank you and everyone who worked with you. I am confident your work will stand as the preeminent documentary film not only of the Vietnam War but of all wars. It will stir millions of hearts in America, in Vietnam, and around the world. The film is a fitting final chapter to the war. I’m proud to appear in it. I can’t wait to watch the entire film. I am also eager for my family and my former comrades in arms to see it.”