Moscow — The Olympic flame will be burning a bit dimmer in 1984, just as it did in 1980. One of the world's greatest sporting powers, the Soviet Union, says participation by its athletes in this summer's Olympic Games in Los Angeles is ''impossible.''
The stated reason is alleged violations of the Olympic Charter by US authorities. The real reason is bound up in superpower politics and rivalry - and in intense national pride.
In one of those ironic coincidences that form the footnotes to history books, the decision was announced on the same day that runners began carrying the Olympic flame cross-country from New York to Los Angeles.
The next hurdle facing the Los Angeles games: whether Moscow's East-bloc allies will follow suit and boycott the games.
(According to a senior Reagan administration official, the Warsaw Pact countries also will not participate.)
East Germany could find it hardest to stay away. It is a strong competitor and places a high priority on winning medals in Olympic Games, partly as a means of stressing its own legitimacy as an independent German state.
Hungary and Bulgaria in particular have loyally followed Moscow's lead in the past. Poland and Czechoslovakia, as well as East Germany, are doubtless under pressure from Moscow to do the same.
Still, the nonparticipation of the Soviet Union (the Soviets have carefully avoided using the word ''boycott'') comes as a major blow to the Los Angeles games.
The Soviets laid the blame for the decision not so much on Los Angeles Olympic Organizing Committee officials as on the Reagan administration.
In an official statement, the National Olympic Committee of the Soviet Union claimed that the Reagan administration, ''from the very first days of preparations,'' had planned on ''using the games for its political aims.''
It claimed that United States authorities were guilty of ''connivance'' with ''extremist organizations'' who were trying to create ''unbearable conditions'' for Soviet athletes and coaches - an apparent reference to the Ban the Soviets Coalition, which had planned to encourage defections by East-bloc athletes.
The fear that the organization might have been successful must have played at least some part in the decision not to participate.
But there are other reasons behind the move.
Although Soviet authorities will never officially admit it, they are exacting belated retribution for the US boycott of the Moscow Olympics of 1980. That boycott still stings here in Moscow.
The lingering bitterness still creeps into conversations four years later, when, for example, a Soviet athlete shows a visiting American around the Olympic swimming pool in central Moscow.
Soviet authorities played on these sentiments - and carefully manipulated them - in laying the groundwork for the announcement that the Soviet team would stay home. Over the past three months, there has been a steady drumbeat of criticism of the Los Angeles Olympics in the government-controlled press and news media.
Soviet citizens were told that the US was laying plans to harass Soviet athletes and was unfairly discriminating against Soviet officials in advance of the Olympics. They were also informed that the US had prevented the Soviet Olympic attache, Oleg Yermishkin, from entering the US. They were not told, however, that he is accused by the US of being a spy for the KGB.
By so directly linking President Reagan to the controversy, the Soviets were clearly underscoring the political message behind their decision. Soviet officials have made it clear they refuse to do anything that might help the President's reelection effort. Some high-level officials apparently felt that participating in Olympic Games in the President's home state, especially during an election year, might serve that end.
And the Kremlin apparently decided that such a dramatic gesture might underscore its bitter opposition to the stationing of new US-supplied nuclear missiles in Western Europe. At no time did they link these issues in official statements. That would have sounded too much like President Carter's 1980 decision to boycott the Moscow Olympics in protest over the Soviet invasion of Afghanistan.
Still, the reasons that were stated, centering around alleged violations of the Olympic Charter, were characterized by a Western diplomat here as ''pretty weak.''
Still, sports are a national passion in this country, and the decision must have been an especially difficult, perhaps even painful one, for the Kremlin.
Even while the official Soviet media were criticizing the Olympics, Soviet officials were privately assuring Western observers that the USSR would eventually field a team.
But a tip-off to the Kremlin's intentions came on the morning of Tuesday, May 8 - the day the decision was announced. Four of Moscow's newspapers carried letters from readers, in what was apparently a carefully orchestrated campaign to show public support for a boycott. One letter spoke of the ''terror'' that athletes would face in Los Angeles. The general thrust of all of them was that the Soviet team should stay away.
In this way, the Kremlin had created what amounted to a groundswell of public support for its move - even before it was announced.
Marshall Ingwerson reports from Los Angeles:
Until this week, the Los Angeles games this summer seemed destined to be the biggest Olympics ever staged, with some 10,000 athletes from 150 countries competing.
If the Soviet Union, in fact, stays home from the Olympics this summer, how much damage will be done to the Los Angeles Games?
Peter Ueberroth, president of the Los Angeles Olympic Organizing Committee (LAOOC), has stated all along that his committee has prepared for all kinds of contingencies, including a boycott by the Soviets, the East-bloc nations, and much of the third world.
The L.A. Games, he has maintained, would be put on without a deficit if that happened. If the financial health of most LAOOC operations are any guide, most Olympic observers are inclined to believe his claim.
But a Soviet no-show will definitely cut the committee's budget, while not cutting its expenses nearly as much. The LAOOC contract with the ABC television network, for example, which supplies nearly half of the revenue for the games, has a clause lowering their $225 million fee in the event the Soviets don't participate.
More important to most people, especially the athletes themselves, is the impact of the Soviet decision on the quality of the competition.
The key, according to Olympics watchers here, will be how many other nations follow the Soviet lead.
Most think the East-bloc nations are likely to do as the Soviets do. These nations historically win more than half of the medals in the games, according to Olympic historian Richard Espy. ''The quality of the games will be seriously diminished.''
Whether any third-world countries boycott the games depends largely on what kind of pressure the Soviets exert. Carol Thompson, an associate professor at the University of Southern California and an expert on the politics of sport, has just returned from Africa, most of which boycotted the 1976 Olympics.
''My sense is that the Africans are making every effort to come,'' she says. ''Some that lean to the USSR may not, but my sense is that most African countries will show.''
Because the Soviets' stated reasons for not participating are more technical than political, and they have insisted that their move is not a boycott, experts assume they won't be overtly pressuring other nations to to stay home.
Yet African nations have some reasons to be sympathetic to the Soviet position, Thompson adds.
First, the Soviets have been instrumental in helping these countries keep South Africa out of the Olympics, ''so they have some chips to cash in.''
Further, many Africans may share Soviet reluctance to allow President Reagan an Olympic platform for what amounts to a foreign policy success, that is, a successful Olympics.
In Asia, she points out, any Soviet pressures would be at least partly counterbalanced by the Chinese, who are participating in the games for the first time this year.
If the Soviets and others don't appear, it will be the third major Olympics boycott in a row - the others being black Africa in 1976 and the United States in 1980.
This, says Espry, ''could destroy the games as we know them.''
The damage, Thompson points out, would fall not to the LAOOC as much as to the International Olympic Committee. The Soviets and the third world have complained for decades, she says, about that ''totally out-of-date, old-fashioned oligarchy.''