An important film is opening here Friday that will be of particular historical interest to the members of the "duck and cover" set. "Atomic Cafe" is a 90-minute journey back to the time when American school children were trained to dive under their desks and cover their heads during an atomic attack, when families built bomb shelters, when the American government shamelessly fanned the flames of anticommunist hysteria while soft-pedaling the destructiveness of atomic weapons.

The film, a compilation of news clips, government and military training films, could not have come out at a more appropriate moment. For the first time in two decades the American people are genuinely frightened about nuclear war, and we appear to be genuinely anxious to do something about the arms race. The political pressure is so intense that the arms control movement has even spread to the White House.

A great public debate is under way on how to manage the weapons we have created, and a very real part of the debate is going to come down to a question of the government's credibility. That the public is not as naive as it used to be was shown by the reaction to Gen. T.K. Jones' pronouncement that "everybody's going to make it" through a nuclear war if there are enough shovels around for people to dig holes, cover them with doors, and throw three feet of dirt on top. As shocking as that statement was, "Atomic Cafe" shows that a cavalier attitude toward atomic war is part of a long and dangerous military tradition that goes all the way back to the pilot who described dropping the bomb on Nagasaki as "my greatest thrill."

The film originated with producer Kevin Rafferty, 34, a film maker who graduated from Harvard and who wanted to do a study of American propaganda films in World War II. "It all led in and out of Hiroshima," says Rafferty. And it is there, on the leveled earth that was once a city, that the film begins. We see mercifully brief shots of the burn victims, the unimaginable human suffering caused by the first bomb, and then we hear President Truman talking about praying to God that we will use the bomb for His purposes. That a president could get away with cloaking his use of atomic weapons in religion is but one of the film's measures of the naivete with which the American public greeted the atomic age.

Later we see the natives on the Bikini atoll welcoming the American bomb testers who assure them that they want to turn "this great force into something good for mankind." The natives evacuate their land, singing "You Are My Sunshine," never dreaming their island would be too radioactive for use and never dreaming they would get cancer from the fallout.

The film clips recall some of the tragic accidents that occurred during the weapons testing, the shifting of wind that took radiation into inhabited areas and burned people in the fallout path and the Japanese fishing boat with 23 crewmen who were hit by fallout. It shows a military chaplain telling soldiers that "watched from a distance, this explosion is one of the most beautiful sights seen by man," and, so inspired, the soldiers watched the Nevada tests from trenches and then advanced innocently onto ground zero as part of a training exercise.

The film ends with a civil defense film clip showing how a family survives nuclear attack: The family hops down the chute into its handy fallout shelter and stays there until the bombing is over. The clip then shows the bombing, the firestorm, the heat, the flying debris. The father emerges and goes into the house, where a picture frame is ajar and there is a lot of shattered glass. (Honest.) "We've been pretty lucky," the father announces. "There's nothing to do but clean up and wait for word from the authorities and relax."

This propaganda is part of our atomic heritage, and ought to be kept firmly in mind as the public considers the administration's emergency preparedness relocation plans. "Atomic Cafe" will do nothing to shore up confidence in our leaders. Quite the contrary: it shows the jingoism, transcendent ignorance, and arrogant self-righteousness with which this nation handled the early atomic bombs. It is a devastating indictment of the military and the government and their failure to inform the public as to the true nature of nuclear weapons. If the public was naive then, the film argues compellingly that it ought to be very skeptical now.