If someone should feel compelled to make a film about 9/11—specifically, about the social and psychic toll that the attacks have and haven't taken—a good model would be Akira Kurosawa's I Live in Fear, out on DVD in the Criterion Collection's Eclipse series.
Made in 1955, just a decade after Hiroshima and Nagasaki, the film stars Toshiro Mifune, Kurosawa's favorite actor, as an aging Japanese industrialist named Kiichi Nakajima who grows so anxious about the H-bomb that he decides to sell his foundry and move his entire family to Brazil—beyond the range of the radioactive fallout from a nuclear war between the superpowers.
Nakajima's sons don't want to move, or lose their inheritance, so they petition the courts to declare their father mentally incompetent. Nakajima can't understand why no one else seems to see the danger as clearly as he does. Finally, when a son-in-law explains to him that not even Brazil would be spared from the fallout—that living with the bomb is inescapable—he plunges into madness and winds up in an asylum, with a deranged grin on his face, hallucinating that he's fled to another planet. Meanwhile, one of the judges who ruled in the sons' favor—a gentle dentist named Dr. Harada—has come to feel guilty about his verdict. He's been reading a book about nuclear fallout, called The Ash of Death, and wonders if the man he committed might not be crazy after all.
The film's final shot takes place on a stairway in the asylum. One of Nakajima's daughters is walking up the steps to see her father. Dr. Harada is trudging down the same steps, having just paid a visit, and he is heading back out into the street. The clear question: Which of them is about to go mingle with the insane? Which world is crazier—Nakajima's or the real one?
It's a rather unsubtle message, but Kurosawa compensates with an understated visual style. According to his autobiography, he started using three cameras around this time, letting them all roll while the actors played the whole scene as if in a stage play, then choosing the best angles in the editing room. It gives the film a documentary feel—many scenes are shot from behind the characters—as if we're peeking in on a slice of life. (The British title for the film, which, I'm told, more closely matches the Japanese, is Record of a Living Being.)
Kurosawa shows a world in which the most dreadful dangers are shrugged off as routine. Sirens wail in the background all through this film; it's not clear what kinds of sirens (police, ambulance, air-raid drills?), and nobody pays attention anyway. In one harrowing scene, Nakajima visits one of his young mistresses and their infant daughter (the man is no saint). We hear the sound of two jets, probably American fighter planes on alert, streaking overhead: He looks up; his mistress continues with her kitchen chores. Then we see a flash. He dives onto the floor, to protect his son. He's cowering, shaking; the baby wakes up, crying from the disturbance. It turns out the flash was just lightning. It begins to rain, and his mistress looks at him as if he's nuts.