"The Soviets don't start a fight like this with the intention of losing it," said a veteran Western diplomat here over the weekend as he contemplated the unprecedented civil slander suit against Craig Whitney of The New York Times and Harold Piper of The Baltimore Sun.

"Can you imagine sending an American correspondent into a courtroom packed with jeering handpicked spectators?" said another. "They would be wrong to go in there at all."

"Soviet law is what the Soviets say it is," said a third. "They would put Whitney and Piper on the stand and then start asking who their sources where.They can do anything they please, anytime they want."

The dismal conversation this sundrenched weekend in the foreign community here turned on the situation of Whitney and Piper. The newsmen are scheduled to return before Moscow city court President Lev Almazov today at noon to either provide him with detailed written responses to his extended deadline and request more time to work on their defense or indicate that they feel they cannot get a fair trail and thus may not participate during the Friday hearing.

Whatever course the newsmen take, their decisions are important, difficult and hazardous. This is because of the bizarre aspects of the complaint against them and the peculiar reality of life here in the Soviet Union where the legal system is often used to pursue, achieve and ultimately, legitimize a political goal.

How Whitney and Piper proceed the success they have in explaining their positions, and how the government responds to them will have major impact on the way foreign correspondents report on the Soviet Union.

The government's interest in a finding of guilt against Whitney and Piper is transparent. On May 19, the State Television and Radio Committee broadcast during a national nightly-news show a powerful segment in which convicted Georgian separatist and dissident figure Zviad Gamsakhurdia pleaded guilty to anti-Soviet propaganda.

"I sincerely regret what I have done and repent," he said.

Five days later, articles by Whitney and Piper ran in their papers quoting unnamed dissidents as doubting the authenticity of the confession. The Baltimore Sun and The New York Times are not available here, but the Voice of America and other radio networks beamed these reports into the country.

Little more than a month later, the State Committee on Radio & Television charged Whitney and Piper with slander.

The complaint badly ascribes to the newsmen themselves the doubts expressed by the unnamed dissidents.

If Whitney and Piper tackle the legal questions raised by the suit, they could keep international specialists in communications law preoccupied for some time to come.

The charges cite Article Seven of the civil code, which defines "slander" as "dissemination" of injurious material. Whitney and Piper themselves did not disseminate the alleged slander, however. They transmitted their articles to Europe and then on to their papers. It was up to the eidtors in the United States to determine whether the articles should be disseminated. The suit does not reach to this point with its potential for applying the jurisdiction of Soviet law far beyond Soviet borders.

The remedy for slander in Soviet law is a "printed retraction." If the publication refuses voluntarily to print the retraction, the plaintiff may take an advertisement and charge the cost to the losing defendant. It is not clear whether the court would require the retractions to be published in Soviet newspapers or in the newspapers in which the articles originally appeared.

If the court finds the two newsmen guilty of slander - as many foreign observers here believe is a foregone conclusion - how can the newsmen publish a retraction? They are not empowered to tell their newspaper what to do in these matters. And the editors who presumably have such responsibilities are not parties to the suit.

These questions alone raise serious doubts here about the legal bsis of the proceedings. To many whose views have been sought in recent days, the slander action, although a crude legality, is purely political.

This line of argument, persuasive in the current atmosphere of bad relations between Moscow and Washington, is that the Soviet leadership will be firm in stifling domestic dissent regardless of the anger it causes in the West.

The U.S. ambassador, Malcome Toon, in a rare public accusation Friday, called the suit a "challenge" to American correspondents who have written articles about the small band of human rights activists, nationalists, religious believers, and Jews who have been denied exit visas.

Whitney and Piper indicated after their session Friday with Almazov that because of "obscure political aims," the proceedings was not designed to be fair, but simply to yield a guilty verdict. Therefore they may not participate. This path raises problems for the correspondents. If they withdraw, some may take it as a sure sign that they indeed committed slander and were afraid to face the consequences in court.

Full participation also raises serious questions and doubts. It is a fair question to ask whether the two newsmen can indeed get impartial treatment in a proceeding which has already been heavily politicized.

If Whitney and Piper submit a witness list, they would compromise their sources, who spoke to them on the quite understandable condition of anonymith. Yet the judge has indicated that lack of a witness list is worthy of his critical comments.

Whitney and his bureau chief, David Shipler, have spent the weekend conferring with Leon Lipson, a Yale Law School specialist in Soviet law who the Times flew here from London where he was finishing a sabbtical. Piper has had preliminary conversations with a Soviet lawyer, Genrikh Rubezhov, who was recommended to his editors by Harvard Law School professors.

The nature of the discussions between the reporters and these lawyers is unknown.

One certain aspect is that if the correspondents are going to attempt a full legal defense, they will need much more time than the five days allotted prior to trial. If they seek the time and if the judge grants it today will help make clear which parth the newsmen will try to take and upon which path the state has decided.