The film postulates a fictional war between NATO and the Warsaw Pact over Germany that rapidly escalates into a full-scale nuclear exchange between the United States and the Soviet Union.

[6] Dr. Russell Oakes works at a hospital in Kansas City, Missouri, and spends time with family as his daughter Marilyn prepares to move away.

Airman Billy McCoy, serving with the 351st Strategic Missile Wing, is stationed at a Minuteman launch site in nearby Sweetsage, one of many such silos in western Missouri.

Pre-med student Stephen Klein decides to hitchhike home to Joplin, Missouri, while Denise's fiancé Bruce witnesses a crowd of shoppers frantically pulling items off the shelves as both sides attack naval targets in the Persian Gulf.

Oakes receives fallout reports by shortwave from KU professor Joe Huxley in the science building: travel outdoors is fatal.

The film ends with an overlying audio clip of Huxley's voice on the radio as the screen fades to black, asking if anybody can still hear him, only to be met with silence until the credits, as a Morse code signal transmits a single message to the viewer: M-A-D.

The Day After was the idea of ABC Motion Picture Division President Brandon Stoddard,[7] who, after watching The China Syndrome, was so impressed that he envisioned creating a film exploring the effects of nuclear war on the United States.

Hume undertook a massive amount of research on nuclear war and went through several drafts until ABC finally deemed the plot and characters acceptable.

Hume and Papazian ended up selecting Lawrence because of the access to a number of good locations: a university, a hospital, football and basketball venues, farms, and a flat countryside.

Back in Los Angeles, the idea of making a TV movie showing the true effects of nuclear war on average American citizens was still stirring up controversy.

Finally, in May, ABC hired the feature film director Nicholas Meyer, who had just completed the blockbuster Star Trek II: The Wrath of Khan.

Meyer plunged into several months of nuclear research, which made him quite pessimistic about the future, to the point of becoming ill each evening when he came home from work.

Meyer and Papazian also made trips to the ABC censors and to the United States Department of Defense during their research phase and experienced conflicts with both.

In between casting in Los Angeles, where they relied mostly on unknowns, they would fly to the Kansas City area to interview local actors and scout scenery.

When asked about its plans for surviving nuclear war, a FEMA official replied that it was experimenting with putting evacuation instructions in telephone books in New England.

ABC originally planned to air The Day After as a four-hour "television event" that would be spread over two nights with a total running time of 180 minutes without commercials.

[8] The director Nicholas Meyer felt the original script was padded, and suggested cutting out an hour of material to present the whole film in one night.

[10][11] Josh Baran and Mark Graham were anti-nuclear activists who were secretly given a bootleg copy of the film by Nick Meyer prior to the ABC broadcast.

One scholar said they "pioneered the piggybacking of a public issue onto the release of a commercial media product", and Variety called it "the greatest PR campaign in history.

Another scene in which a hospital patient abruptly sits up screaming was excised from the original television broadcast but restored for home video releases.

The film was shortened from the original three hours of running time to two, which caused the scrapping of several planned special-effects scenes although storyboards were made in anticipation of a possible "expanded" version.

They included a "bird's eye" view of Kansas City at the moment of two nuclear detonations as seen from a Boeing 737 airliner approaching the city's airport, simulated newsreel footage of U.S. troops in West Germany taking up positions in preparation of advancing Soviet armored units, and the tactical nuclear exchange in Germany between NATO and the Warsaw Pact after the attacking Warsaw Pact force breaks through and overwhelms the NATO lines.

Also cut were images of radiation sickness, as well as graphic post-attack violence from survivors such as food riots, looting, and general lawlessness as authorities attempted to restore order.

RCA videodiscs of the early 1980s were limited to 2 hours per disc so that full screen release appears to be closest to what originally aired on ABC in the U.S. A 2001 U.S. VHS version (Anchor Bay Entertainment, Troy, Michigan) lists a running time of 122 minutes.

[15] A two disc Blu-ray special edition was released in 2018 by the video specialty label Kino Lorber and present the film in high definition.

ABC then aired a live debate on Viewpoint, ABC's occasional discussion program hosted by Nightline's Ted Koppel, featuring the scientist Carl Sagan, former Secretary of State Henry Kissinger, Elie Wiesel, former Secretary of Defense Robert McNamara, General Brent Scowcroft, and the commentator William F. Buckley Jr. Sagan argued against nuclear proliferation, but Buckley promoted the concept of nuclear deterrence.

[25] Producers Sales Organization released the film theatrically around the world, in the Eastern Bloc, China, North Korea and Cuba (this international version contained six minutes of footage not in the telecast edition).

The actor and former Nixon adviser Ben Stein, critical of the movie's message that the strategy of mutual assured destruction would lead to a war, wrote in the Los Angeles Herald-Examiner what life might be like in an America under Soviet occupation.

[27] The television critic Matt Zoller Seitz, in his 2016 book co-written with Alan Sepinwall, TV (The Book), named The Day After as the fourth-greatest American TV movie of all time: "Very possibly the bleakest TV-movie ever broadcast, The Day After is an explicitly antiwar statement dedicated entirely to showing audiences what would happen if nuclear weapons were used on civilian populations in the United States.

He suggested the story had origins in editing notes received from the White House during the production, which "may have been a joke, but it wouldn't surprise me, him being an old Hollywood guy.