Peace is at hand for viewers of the WGBH, Boston, reprise of the Vietnam war. It is now almost 13 weeks since PBS began airing Vietnam: A Television History (Tuesdays, 9-10 p.m., check local listings for premiere and repeats). With ''The End of the Tunnel (1973-1975)'' on Dec. 13 and ''Legacies'' Dec. 20, this unique series comes to an end . . . on the air but not in the hearts and minds of those who have watched.
It has become a critical cliche to call ''Vietnam'' a ''landmark'' series, but there are few other words to describe it. Never before has there been so successful an attempt so soon after a momentous world event to assimilate the facts.
''Vietnam'' has managed to be understanding, probing, incisive, interpretive, and at the same time balanced and fair to all sides. It has brought a long-range sense of proportion to this conflict. If there is a word other than ''landmark'' that fits the series it is ''perspective.''
Without any hint of smugness or pedanticism, the American end of the team - executive producer Richard Ellison and chief correspondent Stanley Karnow, with the aid of media researcher Lawrence Lichty and a staff of skilled writers, directors, and producers - has managed to bring enlightenment and perspective to a problem that has deeply troubled the world. The series is a co-production with Central Independent Television/U.K. and Antenne-2/France in association with LRE Productions.
In the Dec. 13 segment, the final two years of the American involvement is painfully described with the aid of many participants in the events and with film footage from Hanoi archives. The total chaos of the final evacuation is evoked as active US participation in the war fades.
In the Dec. 20 final segment, there is a brave attempt to sum up, but in the end an acknowledgment that it would be arrogant to assume we can accurately assess what has happened before world events reveal what the future has in store for Vietnam and for the United States in terms of its foreign involvements.
''Legacies'' is scrupulously fair as it traces not only what happened to the US but also what has subsequently happened to North and South Vietnamese, Chinese, Soviets, and Cambodians. It reports that nearly 700,000 Indochinese (mostly Vietnamese) have sought refuge in the US.
The narrator concludes: ''Vietnam can be viewed in retrospect as the last and longest of the post-World War II colonial conflicts. It can be viewed as a civil war. It can also be viewed as an episode of the cold war like Korea in the early 1950s. But whatever the view, it was a tragic war for the peoples of Vietnam, Cambodia, and Laos. Peace has left them poverty-stricken, oppressed, and almost entirely dependent on the Soviet Union. And communist Vietnam is still America's enemy. The war that was never declared has never ended. For many Americans, Vietnam the country has become Vietnam the lesson.
''The generation now reaching military age was not born when the marines first landed in Vietnam. Their father's view of the world was shaped in part by World War II, recalling Munich and how Austria, Czechoslovakia, Poland, and the rest of Europe fell like dominoes before the Nazis. They led America into Vietnam. The youth of the 1960s are the Vietnam generation. Whether they fought the war or fought against it, they can never forget it. And each must now seek its meaning.''
''Vietnam: A Television History'' will be shown in the classroom, distributed on cassette, and repeated on television for many years to come.
I believe that the series itself can serve as a kind of modern-day Rosetta Stone for future generations trying to ''define the meaning and determine the lessons of Vietnam.'' Chat with two who worked on 'Vietnam'
Was the Vietnam war really a living room war? Did the sight of killings on TV really turn the American people against the war, as has been claimed?
I asked that question of the chief correspondent for ''Vietnam: A Television History,'' Stanley Karnow, a syndicated columnist and veteran war correspondent, whose companion book to the series (''Vietnam: A History,'' Viking Press, $19.95 ) is now nearing the top of the best-seller lists.
Mr. Karnow's answer: ''No. I don't want to say that television had no influence whatsoever - that would be ridiculous. But I do think that there are other factors that were much stronger in influencing people and changing opinions. People don't watch television news as much as television executives like to think they do.
''I think direct things have much more impact on people than what they see on the screen or read in the papers. For example, if kids in the neighborhood get killed, or five kids in the local high school, that has a tremendous impact on people, much more than television does.
''Things like in 1967 when President Johnson increased taxes, imposed a tax surcharge. You could see that correlated directly to public opinion. That had more effect than what they saw from Vietnam on the TV screen.
''The pocketbook is one factor. The casualty rate is the main factor. And the third, more important than television, is that there was no way to measure progress in the Vietnam war. If you compare it with the Second World War, you could stick pins in maps and see progress in Normandy then. But in Vietnam there was no way to measure progress, because we weren't fighting for territory. (Gen. William C.) Westmoreland called it a strategy of attrition, to keep killing enemy troops so that the communists would eventually withdraw and leave an independent South Vietnam. But what he discovered was that there was no limit to the casualties the enemy was prepared to take.
''The influence of TV has been exaggerated. I think that in the search for some kind of scapegoat to blame the loss upon it was convenient to blame TV.
''When Walter Cronkite went on TV in February 1968 and expressed doubt about the war for the first time, Lyndon Johnson is supposed to have felt he was losing the public if he lost Walter. . . . Well, I suggest that Walter Cronkite was reflecting public opinion more than he was changing it. He was finally catching up with public opinion, which had begun to change six months before he said it.''
So why does Karnow bother to do this Vietnam series if he doesn't believe that TV is much of an influence?
''I think it can be one of many influences. Especially in the area of historical background. People are asking me why they hadn't been informed about the past in Vietnam. The current series is dramatizing a lot of history for them. Television in the Vietnam days wasn't doing much historical backgrounding. People are now also saying, 'Why aren't we stopping and taking a long look at the background of the conflicts in Central America?' I think TV is beginning to answer those demands.
''The series and my book have come at a time when people are sensitive to all these foreign involvements and because the Vietnam war has become a metaphor for other involvements. People are watching the series and asking the question: 'Is there anything we can derive from that experience which will guide us in the future?' ''
Lawrence Lichty, director of media research for the series, was a professor of communications arts at the University of Wisconsin for 13 years and currently teaches media history at the University of Maryland. Here's how he told me he feels about Vietnam as a living-room war: ''The evidence indicates that first of all the people who turned against the war were people who first had more information, who watched less television. In other words, the group that turned the most in opposition to the war tended to be in higher educational categories. They tended to have more information, pay more attention to the newspapers.
''Tests reveal that, unfortunately, people who watch television news don't remember specific stories and they don't learn very much. That doesn't change the fact that maybe there is a slower, more impressionistic kind of learning that's not very well measured by those kinds of tests. I think the most important thing for someone who watches the series is to learn something about the subject matter and then go out and read a book . . . hopefully Stanley Karnow's.
''The extent to which politicians think people pay a lot of attention to television means that in an indirect way television influences public policy. Whether Walter Cronkite was influencing public opinion was not so important as the fact that Lyndon Johnson thought so.
''I think in the case of Vietnam that American public opinion changed and as it changed journalists saw that and the journalists reflected that change.''
So what can this TV series accomplish?
''We got the film collected and the people interviewed. It's hard to know if that could be done 2 or 5 or 10 years from now. . . . Another thing is that if you get people interested in the issues of Vietnam - and they may not learn a whole lot from the series - but if they get interested in history, that's important, too.
''I hope the series gives people greater perspective. But people take away from any communications medium pretty much what they take to it.''
Although I respect the learned opinions of both Stanley Karnow and Professor Lichty, as a television critic who observes television shows and television audiences on a daily basis, I must disagree with them. It is fanciful thinking to believe that what people see repeated constantly on TV is not a major factor in their attitudes. The daily dose of carnage on TV news during the Vietnam war certainly contributed greatly to a nationwide desire to see the conflict ended, just as the TV pictures of marine casualties in Beirut today is contributing to puplic pressure to bring the marines back as soon as possible.
Whether that effect is good or bad, right or wrong, is another matter. But I find it difficult to minimize.