After a two-week recess, jurors in retired general William C. Westmoreland's $120 million libel action against CBS, Inc. today saw for the first time letters a young intelligence officer sent to his wife in 1968 claiming that "truly gargantuan falsehoods" were being told by Westmoreland's command in Vietnam.

The letters, written by Navy Cmdr. James Meacham, now military correspondent for The Economist in London, were used by CBS producer George Crile in putting together the CBS documentary at issue in this case. The program charges Westmoreland with being part of a conspiracy to fake intelligence in this crucial period of the war.

However, Meacham, who is not expected to testify, later disputed the substance of the letters. Meacham said in a 1983 affidavit for the case that "I never intended that the harsh language in those letters be taken literally . . . . "

"The rhetoric in those letters is exaggerated and does not reflect my calm judgment on events of that time," he said in the affidavit. "I think it is wrong for anyone to use those letters to try to show that MACV was 'faking intelligence' because that is something MACV did not do." MACV, or Military Assistance Command, Vietnam, was Westmoreland's command.

Crile, who resumed his testimony today after a holiday recess, has contended that Meacham's letters written at the time should outweigh his affidavit 15 years later.

The letters, read to the court and passed out to the jury, told his wife that in one press briefing he helped prepare, "I have never in my life assembled such a pack of truly gargantuan falsehoods. The reporters will think we are putting on a horse-and-dog show when we try to sell them this crap." The Meachams have since divorced.

A key issue in this case, as outlined by Westmoreland's attorneys, is whether the general tried to keep key intelligence data from the president, not whether he lied to the press.

However, in another letter, Meacham described a visit to Saigon by a number of officials from the Defense Intelligence Agency.

He wrote that "more and more, the Washington bunch is beginning to dig into this strength business, and they are beginning to smell a rat, I think.

"Someday it may come out how we have lied about these figures," he said.

The letters became a part of the official court record today as Crile, in his eighth day on the stand, was questioned by CBS attorney David Boies about the broadcast.

Crile, who is also expected to answer questions Friday from Westmoreland lawyer Dan M. Burt, also used the period of friendly questioning by Boies to praise another co-defendant in the case, Samuel A. Adams.

Adams, a former CIA analyst whose information was the nucleus of CBS' documentary, was a paid consultant for the CBS Reports program, "The Uncounted Enemy: A Vietnam Deception." The show charged that Westmoreland and other top government officials conspired to hold down enemy troop numbers in 1967 to maintain support for the war.

In contrast to several former military and intelligence men who testifed for Westmoreland that they believed Adams was "obsessed" about the 1967 debate over enemy forces in Vietnam, Crile said that he believed at the time Adams was working with CBS on the broadcast that he was "both a man of great competence and, in certain respects, brilliance . . . .

"I also found that Mr. Adams was a man of extraordinary integrity," Crile said.

Giving essay-length answers, Crile went on to say that as a journalist he was familiar with governmental whistle blowers who tell their stories out of "hatred or anger."

But he argued that Adams had first tried to work within the CIA and finally had gone outside, writing a story for Harper's that Crile, who worked for the magazine at the time, edited.

Crile said a congressional committee on intelligence evaluated Adams' charges and "had come to believe that Sam Adams was not only a man of great integrity, but that he had been right and that what we needed was more Sam Adamses in the CIA."

Adams is not expected to testify until after Boies begins arguing the CBS side of the case, possibly by mid-January.