CBS News is taking very seriously charges made against it by TV Guide in its current cover story, "Anatomy of a Smear: How CBS News Broke the Rules and 'Got' Gen. Westmoreland."

There definitely is a limit, though, on how seriously these charges should be taken.

In the article, reporters Don Kowet and Sally Bedell claim that "The Uncounted Enemy: A Vietnam Deception," broadcast by CBS on Jan. 23 of this year, was "often arbitrary and unfair in its approach" and cite examples of alleged "inaccuracies, distortions and violations of journalistic standards" committed by producer George Crile and others involved in the program.

The broadcast, which included a Mike Wallace interview with Gen. William C. Westmoreland, attempted to prove that during the Vietnam war, the American military intelligence establishment, under Westmoreland's supervision, intentionally underestimated the size and strength of the enemy in reports to make it look as though the war was going much better than actually was the case.

In a review of the program, Washington Post National editor Peter Osnos, who served as a correspondent in Vietnam, called it "powerful and timely" and "first-rate" and pointed out that the charges against Westmoreland had previously been raised elsewhere.

Even the hostile TV Guide article labeled the documentary "an ambitious attempt to shed light on one of the most important debates in recent American history." But it then went on to charge CBS News with a variety of journalistic sins, claiming, among other things, that CBS ignored, and declined to air, any evidence that did not support its thesis of conspiracy.

Unfortunately for authors Kowet and Bedell, their piece would have much more credibility and considerably more impact if it had appeared anywhere other than in TV Guide, a magazine with virtually no tradition of investigative reporting. TV Guide is owned by Walter H. Annenberg, a conservative multimillionaire and longtime devoted Republican.

Now, conspiracy theories in this country don't just come cheap; they're free. Why, if you really had a mind to, you could dredge up heaps of circumstantial evidence suggesting Annenberg has a vested political interest in anything that makes the network news boys look like rascals.

Not only was Annenberg bosom buddies with Richard Nixon, but Nixon appointed him ambassador to the Court of St. Jame's, a gig Annenberg turned into quite a hoot. He also is an intimate pal of Ronald Reagan. Annenberg donated $70,000 to Nancy Reagan's White House fixup kitty, and his wife, Leonore, served for a time as Reagan's chief of protocol.

The Reagans spent New Year's with the Annenbergs, as they customarily do, at "Sunnylands," the Annenbergs' Palm Springs estate, where Annenberg entertained the exiled shah of Iran in 1979. In March, TV Guide published an "exclusive interview" with Reagan in which Reagan grumped about leaks to the press. Only two weeks ago, Annenberg himself had a TV Guide byline, decrying, in a "commentary" called "The Fourth Branch of Government," the appearance on TV of "adversary journalism and advocacy journalism, which are by their very nature biased." Not a single example of either was cited.

"Is it possible any more," Annenberg asked in his editorial, "for a president to win a second term when every day in a majority of homes there is heard doubt about his wisdom, about his motives?" Annenberg blamed the networks for that.

It was beginning to look as though Annenberg might play for Reagan the same saber-rattling, media-baiting, network-attacking role Spiro Agnew played for Nixon. The White House does not like the networks, and CBS is considered by Reagan forces the most "liberal" of the three.

Now comes this big, splashy attack on CBS News. From his New York office, Kowet denied yesterday that the piece he co-wrote was inspired by Annenberg's politics. "Walter Annenberg had absolutely no input into the piece," Kowet said, and he accused CBS executives of "spreading this allegation for weeks" in order to imply that "Sally and I are puppets on a string who take orders from Walter Annenberg and do a hatchet job on CBS."

Bedell said of the possibility the article was written on Annenberg's orders, "I would have quit if anyone had asked me to do something like that." Actually, she did quit, though not over a policy dispute. She left TV Guide on May 14 and on June 1 reports to work at The New York Times.

David Sendler, national editor of TV Guide, said from the magazine's home office in Radnor, Pa., that Annenberg had no role in assigning the "Smear" piece -- "He doesn't know what we're doing" -- but conceded that Annenberg was delighted with it. "Of course he likes the story. In my judgment, it's the most important story of its kind that we've done."

Annenberg saw the story before it was published, Sendler said, but requested no changes. He told Sendler it was "a fine piece of journalism."

Both Sendler and Kowet say the impetus for the piece came from within CBS News itself; numerous documents were leaked to TV Guide by a friendly source inside. Asked if there wasn't the possibility that he was being "used" by that source as part of some inner-office vendetta, Kowet said, "I know that not to be the case."

He said his source's motive in blowing the whistle was "outrage" over what allegedly had been done. Bedell said there was "more than one" source at CBS News and that she and Kowet were convinced of their sincerity.

CBS News has cautioned employes against commenting until an internal review of the charges is concluded. Insiders say privately that Crile could indeed "eventually" be fired if the more substantial charges are proven correct. But many of the charges are insubstantial or vaguely substantiated -- like the crucial one claiming Crile was hellbent on goring Westmoreland.

The "evidence" cited for this charge rests partly with "blue sheets" -- CBS News inner-office memos -- obtained by TV Guide. The blue sheets are used by producers at CBS News to persuade executives that a story is worth a documentary treatment, and since CBS News only produces 20 documentaries a year, the blue sheets are naturally written to be convincing. They don't dictate or limit the final outcome of a project.

Kowet said he and Bedell had to pitch their own piece to the editors in Radnor as soon as they felt certain they had "pretty serious allegations" on their hands. Thus it could be said of Kowet and Bedell that they produced a blue sheet of their own and that they did precisely what they accuse CBS News of doing: set out to prove a thesis and ignored all evidence contrary to it.

Curiously, the word "smear" does not appear in the story, only in the screaming headlines. Reporters do not write headlines, but Kowet said he is comfortable with the word. He defines "smear" as "an attack on somebody's reputation," which is pretty much Webster's definition. But Kowet also said he does not think CBS News intentionally set out to "get" -- as the headlines puts it -- Westmoreland. "I'm convinced that's not the case. This thing [the documentary] fell through the cracks," Kowet said.

Bedell said, "I wouldn't say there was a conspiracy at CBS to get Westmoreland. But the whole operation prejudged him from the beginning."

Asked if he believed everything the ostensibly maligned Westmoreland had told him, Kowet said, "No. The Westmoreland interview we did actually was . . . not very useful to us . . . Some of the stuff he told us was factually wrong. Whether he was lying or just forgetful I don't know. But he was inaccurate about a lot of stuff." Still, the article claims that Westmoreland was severely wronged by what CBS News chose to include on the air, from Wallace's interview with him, and what it chose to leave on the cutting-room floor.

Kowet and Bedell write in the opening paragraphs of their story about "Vietnam Deception" that their article was prompted in part by "the strong criticism it [the program] aroused." What strong criticism? Kowet said yesterday it consisted of "an exchange of letters in The New York Times," some columns written about the show, and "a certain amount of flak going around Washington." Westmoreland held a press conference denouncing CBS News; but he later apologized for one charge he had made, the charge that Crile never sent him a letter Crile said he had sent, advising him of the kinds of questions Wallace planned to ask. Westmoreland said he suddenly recalled that the letter had been received after all.

Westmoreland's apology is not mentioned in the TV Guide article. "I don't think the fact that he apologized . . . is crucial to our piece," Kowet said -- a flagrant example of eliminating that which doesn't support one's central argument, or simply, as with the CBS News decisions regarding "Vietnam Deception," a journalistic judgment call? Kowet also said he felt certain that Westmoreland was "not ambushed" by CBS.

The more one analyzes the piece, and the more one talks with Kowet, the less grievous seem the alleged wrongs done to the allegedly smeared Westmoreland. Meanwhile, in San Francisco, CBS correspondent Bill Moyers finds himself in the line of fire, fending off grumbles from the CBS affiliates, at their annual meeting. Affiliates love to attack the news division, and they usually shrivel at the thought of controversy. TV Guide and its "Smear" piece have handed them a great excuse for attacking and shriveling, and unfortunately may help bring about a chill on investigative network documentaries -- an endangered enough species as it is -- for weeks, or even months, to come.