George Clooney's film "Good Night, and Good Luck," is an essential historical document; without propagandizing or trivializing, without relying on either distortion or omission, it takes as its subject the short moment - from the fall of 1953 through the spring of 1954 - in which Edward R. Murrow helped catalyze the counterattack on Senator Joseph R. McCarthy. Though today the McCarthy era is either unknown or relegated to a tiny compartment in American history of the mid-twentieth century, those of us who were sentient beings at the time recall very well the fear, the panic, the impotent rage that anyone to the left of Presidents Truman and Eisenhower felt during the postwar years. No one was spared; if your cousin had once read the Daily Worker or voted for the American Labor Party; if you had ever given money to the Highlander Folk School; if, God forbid, you had ever attended a meeting of a left-wing organization while working as a public-school teacher or even as a garbage collector - on the public payroll, that is - you were likely to be fired from your job.

Although this started years before Senator McCarthy arrived on the public scene, he came to symbolize the whole episode. And who was Edward R. Murrow? He had made his reputation as a newsman with his radio reports from London during the Blitz; after the war he became the face of CBS News, and made its name synonymous with accuracy, reliability and integrity. In fact, the whole network basked in the glow of its news department. Today, perhaps only The New York Times has anything like the reputation that CBS News had then.

Clooney, who cowrote (with Grant Heslov) and directed "Good Night, and Good Luck," has cast David Strathairn as Murrow. Although physically not a close match for Murrow, he has captured that quirky, staccato delivery so well that by the time the film is five minutes old, you accept him totally. Clooney plays Murrow's producer Fred Friendly, with a few extra pounds around his belly, crouching under the camera to cue his star on "See It Now," Murrow's weekly news commentary, then going out for drinks afterwards. The film chronicles the months at CBS in which Murrow decides to take on McCarthy, and the ways in which his decision plays out within the news department and upstairs in CBS president William S. Paley's corporate office. Paley is played by Frank Langella with an amazing sense of the techniques by which a corporate mogul accedes, supports and withholds support for those who work for him. Oddly, Paley is unexpectedly the one man whose image stays with us after the film ends; perhaps because he is the only truly conflicted character in the film.

Clooney has shot the film in black and white, a brilliant decision because it enables him to use old kinescope and film footage of McCarthy as himself, instead of trying to find someone who could imitate the senator. And of course no one could imitate a man whose persona and manner were unique. There are a few scenes of internal questioning, and the film deals with New York news anchor Don Hollenbeck, a protégé of Murrow's, so consumed by right-wing attacks that he kills himself. And Robert Downey Jr. and Patricia Clarkson play two news-department employees who are secretly married (against corporate policy prohibiting it). But the film moves through the stages that begin with Murrow deciding to go after the Air Force for discharging Lt. Milo Radulovich because his father was suspected of being a disloyal American, then continuing with his taking on McCarthy. The film's story ends with the iconic Army-McCarthy hearings. And it is bookended with Murrow's speech to the Radio/Television News Directors' Association in 1958, in which he urges them to be courageous.

We see today how that has played out.