Forty years ago this week, ABC Television aired a film that harnessed Americans' very real fear about a possible nuclear attack amid the Cold War.

"The Day After" focused on the city of Lawrence, Kansas. A record audience estimated at more than 100 million Americans tuned in, including then-President Ronald Reagan.

To this day, it is one of the highest-rated television films in history.

“You go to a movie sometimes to leave where you are and escape where you are. You turn on the channel on your TV or on your streaming platform to flip from news to entertainment,” said David Craig, a veteran TV producer and clinical professor at the USC Annenberg School for Communication and Journalism. “These large disaster genre films have their place in the box office. But the point here was around: How do we reach the largest possible audience for a movie that foregrounds a message that is of great urgency?”

Craig is the author of the new book “Apocalypse Television: How 'The Day After' Helped End the Cold War.” In it, he examines how the movie tapped into viewers' psyche by bringing a massive global threat right into their living rooms.

The project’s format, as a fictional movie painting scenes of what could happen after a nuclear strike, was able to reach larger audiences than news programs about the nuclear arms race, Craig said.

“The most pressing issue of that time was the threat of nuclear war, which was escalating,” he said. “Really, everyone in America, really around the world, fully expected that World War III would break out at any moment and the world would come to an end. And it was almost fatalistically understood.”

Adults and children hold tapered candles as they stand outside for a vigil.
FILE - Carol Dorsch, left, and her 8-year-old daughter during a candlelight vigil held after the premiere of television movie "The Day After," on Nov. 20, 1983, in Lawrence, Kansas.
Pete Leabo AP

In Washington, officials in the Department of Defense were concerned about how the film would be received.

“The Defense Department was concerned from the get-go that the project was not very clear politically that the Soviets had caused the attack, and would only participate and provide resources to the production if they changed the script, which they refused to do,” Craig said. “They wanted it to just be about what could happen to everyday Midwestern Americans in the event of a nuclear attack. And they didn't want to make this a war film.”

Religious and political conservatives at the time had come out against the movie because they were concerned that it would persuade people to support a nuclear freeze, he said.

“It did cause a nominal shift in public opinion. But the truth is, public opinion was already very much in favor of nuclear disarmament,” Craig said.

That extended to the White House, he said.

“Unbeknownst to most of us, including me doing this research, President Reagan did not align behind the views of his military in terms of the possibility of a winnable nuclear war or the continuing escalation of the arms race,” Craig said. “This film, according to historians, led to a whole reversal in his rhetoric, his tone, his policy.”

Part of the film’s power came from the programming that followed it, Craig said. It was a special edition of the ABC News program Viewpoint, in which people like scientist Carl Sagan, conservative commentator William F. Buckley Jr. and author Elie Wiesel talked about nuclear policy.

“The world's most well-known public intellectuals, a bunch of older white men who were all experts in their area, sat around the table for the next hour and carried on a very civilized debate over whether or not the world was about to end,” Craig said. “It was shocking because they couldn't decide who was right. But then they open it up to questions, and the audience and everyday people stood up and asked all the questions. We were all desperate to learn and better understand.”

In the age of streaming, television events like “The Day After” are hard to come by. But there are still programs with similar messaging, Craig said, like HBO’s “Chernobyl” and the apocalyptic “The Last of Us.”

“It's a conceit of a post-apocalyptic world filled with zombies and the threat of disease. But every episode of 'The Last of Us' is in fact a mirror of contemporary society and the issues that we're all dealing with every day the minute we walk outside our door,” Craig said. “We think it's a fantasy about the future, but it's actually a commentary about the present. There's always that kind of play and response from Hollywood and storytellers to try to make meaning of these existential and apocalyptic events.”