AS word spread in 1963 that President Kennedy had been shot, millions of Americans desperate for information turned to their televisions. When Walter Cronkite relayed the fact that the president had died, he had to pause to brush away a tear.
The Kennedy assassination, historians say, brought television news into its own and made network anchors a prominent part of public consciousness. Ever since, Americans have turned to them for information and understanding, trusting them to provide straightforward, thoughtful news.
Now the media world the network anchors inhabit is itself in a period of flux, with burgeoning competition, mergers with even larger corporations, and an audience that is steadily declining - as is public confidence in the news media. Critics warn of a world in which overly cautious corporations control more sensational news operations that sacrifice traditional journalistic values for commercial success.
The three leading network anchors are far more optimistic, though still somewhat wary. In Monitor interviews, NBC's Tom Brokaw, ABC's Peter Jennings, and Dan Rather of CBS indicated that they see challenge and opportunity in the changes, including the chance to champion the traditional journalistic values that have generally distinguished their news operations.
''I believe there is some danger in making the news a more remote and a less important portion of whatever humongous global conglomerate that runs the overall enterprise,'' says Mr. Rather who, like his network counterparts, is also responsible for the content of the nightly news. ''But one of the marvelous things about American journalism ... is there has always been a high degree of accountability.''
Rather says the challenge is maintaining that accountability in the changing media environment. And, he notes, there are plenty of people ready to hold the networks' feet to the fire.
Last fall, CBS came in for a barrage of criticism after management forced ''60 Minutes,'' the network's premier news magazine, to pull an interview with a former tobacco executive for fear of a lawsuit.
Indignant critics speculated that the desire to protect the proposed CBS-Westinghouse merger had led nervous executives to allow corporate lawyers to interfere in the news-gathering operation.
Several months later, after the former executive's charges had surfaced elsewhere in the press, network management relented. CBS aired not only the interview but also a lengthy piece on the tobacco industry's efforts to discredit the executive.
Rather called the first decision a mistake but is quick to note it was remedied.
Some critics also fault corporate pressure and the tobacco industry for a tarnishing of ABC News's sterling reputation.
Just before the merger with Disney was announced, ABC settled a $10 billion lawsuit brought by Philip Morris over a 1994 ''Day One'' segment alleging that tobacco companies manipulated nicotine levels to keep smokers addicted. While ABC stood by the report's overall thesis, it apologized for a sentence alleging that Philip Morris ''spiked'' its cigarettes with nicotine from ''outside'' sources. ABC also paid an estimated $2 million in legal fees to the tobacco company.
''I'd like to put the cigarette controversy aside for one moment,'' Peter Jennings says. ''We've never, never been obliged to succumb to commercial pressure ... in the 30 years I've been here.''
Mr. Jennings attributes his program's continued success to the early decision to take ''the high road'' and consistently produce straightforward, serious news.
He also says he believes that tradition will be protected now that the merger with Disney is complete. That's based on comments Disney CEO and chairman Michael Eisner made at a shareholders' meeting in early January .
''They were letter perfect,'' Jennings says, ''exactly what a major broadcast executive should say about his news organization: no fear, no favor, no 'tabloidization'; we will not be subject to undue influence from people who wish to set an agenda.''
For his part, Mr. Eisner says he knew nothing of the lawsuit or the settlement until he read about it in the press. He declined to say how he would have responded to Philip Morris's threat, but implied it might have been different.
''Being a strong financial company gives you the ability to do what's right without putting your company under,'' Eisner says. ''We have the financial strength to stand behind what's right, and we will do so.''
NBC's Tom Brokaw warns against looking into too rosy a rear-view mirror. The concentration of media power in a few hands was ''a lot worse'' in the early part of the century, he says, when a few powerful newspaper families controlled America's principal sources of information. Many owners openly pushed their own political agendas.
''That was a real distillation of power,'' Mr. Brokaw says. ''And the proof of the pudding is always in the eating. So far, there's been no indication whatsoever - internally or externally - of any undue influence of any kind.''
THIRTY years ago, Brokaw notes, there were only two major networks in the full-time news business. Today, all three networks compete, along with CNN, C-Span, talk radio, and an array of other sources of information.
''There are so many choices and so many outlets for criticism, that if something were going on it would come out,'' he says.
But the increasing competition also has a down side. Some critics charge that the three networks have at times blurred the line between news and sensationalism in an effort to keep viewers' attention.
Probably the most egregious example was in November 1992 when ''Dateline NBC'' aired deceptive film of a crash test. (Incendiary devices were used to ensure that a pickup truck would burst into flames when it was broadsided.) NBC publicly apologized. The incident was roundly condemned and still serves as an unpleasant reminder of what can happen when the commercial pressure to keep ratings up clashes with the drier requirements of journalistic integrity.
''There has already been - and everyone in journalism knows it - far too much blurring of the lines between entertainment and journalism,'' Rather says. ''What we absolutely and positively must not do is let entertainment values completely overwhelm news values.''
Brokaw heartily agrees, adding that the challenge for the news business is to take serious, complex issues and report them in a compelling way. But he's also keenly aware of the competition, and that viewers have TV remotes in their hands.
''If [I'm] having an hour on race tonight, and Rather's going to have an hour on crime in the suburbs,'' Brokaw says, ''then somebody who's put in a long day might say, Click! 'Give me ''Seinfeld.'' ' Click! 'Give me ''Chicago Hope.'' ' Click! 'Give me, ''ER.'' ' It's a click away. That's a tough universe in which to compete.''
Some media pundits say the increased competition and blurring of the lines has already diminished the network anchor's prominence and authority. They are not optimistic much will change even as ABC and NBC gear up to start new cable and on-line services. CBS contemplates similar moves.
But other critics disagree, arguing that an anchor's judgment and trademark as the source of legitimate, official news, are even more important as technology creates an avalanche of unfiltered and often-unreliable information.
''Serious people here were always able to do what they thought was serious work,'' Jennings says. ''I don't think the public in the 1990s will be any less demanding of quality news than they have been in the past.''