"The Atomic Cafe" could be the most important film of 1982. To define it as a gripping and frequently shocking documentary about nuclear propaganda in the '40s and '50s only suggests its framework. To describe it as containing some of the blackest apocalyptic humor since "Dr. Strangelove" only suggests the edge of its material. To call it a comic nightmare obscures the fact that this time Freud is being played by the Marx Brothers.

"The Atomic Cafe," opening today at the Inner Circle, is the kind of film that confuses the emotions--should one laugh, or cry? Plan on doing a lot of both.

Filmmakers Kevin and Pierce Rafferty and Jayne Loader have constructed a stunning 90-minute collage of cold-war sociology centered on The Bomb and how we came, if not to love it, at least to live with it. The propaganda clips come from government and military archives, the songs are snatched from ancient public airwaves; the unsettling news breaks in from network television and newsreels. It's all spun and settled into a gradually emerging mosaic of military and political madness, the gorgeous mushroom cloud quickly becoming the definitive metaphor for the apocalypse.

"The Atomic Cafe" follows a fairly strict chronology, from the mid-'40s tests to the Civil Defense paranoia of the '50s, when the Russians got the bomb. The first 30 minutes, which include the drops on Hiroshima and Nagasaki and their subsequent political and moral justifications, show America struggling to integrate the sudden knowledge of this awesome new weapon. While a comedian cracks that Hiroshima looked like "Ebbets Field after a double-header with the Giants," Paul Tibbets, the pilot of the Enola Gay, denies having a guilty conscience.

What makes "The Atomic Cafe" so accessible is the filmmakers' unerring sense of the absurd coupled with a concern that hysteria not repeat itself. They never intrude on the raw material, even as the absurdities pile up:

Cartoon figure Burt the Turtle teaches schoolchildren that, just as he ducks his head inside his shell when someone throws a firecracker at him, they can protect themselves by ducking under desks and covering their heads; if they're on a picnic with their families, why, they can just duck under the blanket and then pop out for dessert.

A Great White Father type assures the innocent natives of the Bikini Islands that they'll be able to come back after a series of tests. Later a narrator confesses, "They don't understand the world of atomic energy anymore than us."

A military chaplain tries easing soldiers' fears as they wait to observe a nuclear test by describing the imminent blast as "one of the most beautiful sights ever seen by man"; as innocent as the Bikini natives, the soldiers believe this and go charging into ground zero as though girls were hidden behind that mushroom cloud, not radiation.

Middle-class suburbanites prepare for the apocalypse by storing their teen-agers' home economics projects (dehydrated fruit, milk and potatoes) and medical supplies (Band-Aids and a family-sized bottle of tranquilizers). Periscope-equipped bomb shelters are kept secret (one owner allows shots of the interior but not the exterior, lest his neighbors come a-calling while the bombs they start a-fallin'). Toward the end, a training film from the '50s shows Dad instructing his family in the basement rec-shelter: "We were lucky. There's nothing to do now but clean up the broken glass, relax and wait for instructions from the authorities."

What emerges through the filmmakers' masterful assembly is an official mind-set that tried to convince the American public that nuclear war was no worse than being snowed in or waiting in line during a gas crisis: The waiting just got done underground.

There's some chilling history to augment the sociology of "The Atomic Cafe:" an outtake of Truman, all smiles before turning it off to make a somber official announcement about the bomb; Eisenhower suddenly appearing as a voice of reason and caution; a brief segment on the Rosenbergs and cold-war ideology (Commie women agitating for peace); the heavy silence as a television discussion of the bomb is interrupted by a newsflash of the first Russian test in 1949.

"The Atomic Cafe," which avoids narrative intrusion, juxtaposes the sights and sounds of an era that may seem as distant to many Americans as the Wild West. It was a period in which the atom bomb evolved from a barely controllable force to a well-understood threat in which all men would be cremated equal. Since then, psychic numbing has turned the bomb into a fairly conventional image. "The Atomic Cafe," brilliantly edited and paced, is a funny, almost innocent place from which to start rethinking the unthinkable.