The Soviet leadership's efforts to eliminate dissent have increased substantially in 1977, with notable success, creating an ominous atmosphere of repression more pronounced in many ways than at any time in this decade.

That view is shared by Western diplomats and journalists who have worked here long enough to make useful comparisons, as well as the remaining dissidents themselves. It is based on the number of arrests, the seriousness of the charges levelled, other forms of harrassment such as searches threats and administrative penalties, and published attacks on foreigners in Moscow, particularly Western correspondents and American diplomats.

None of these, of course, are new measures for the Soviet authorities, who declare openly now as they have always done in the past their aim of wiping out what the Kremlin regards as subversive elements - or as the Communist party newspaper Pravda called them in a major blast last February, "outcastes" and "moral perverts."

What is so striking is the scale of the current drive and some of it especially siniste overtones: charges of treason against certain dissidents who are alleged to have consorted with the CIA, suggestions of anti-Semitism and a palpable eagerness to demonstrate contempt for President Carter's statements in support of human rights with a stepped-up policy of suppression, regardless of the effects on detente.

Assessing the events of recent months, the thoughful dissident historian Roy Medvedev concludes in a paper privately circulating in Moscow, "These are not routine actions of the KGB (security police) but were sanctioned at the highest party level."

Medvedev and others here believe a basic decision was taken by the Politburo last fall to heighten dramatically the pressure on dissidents and cut their contacts with the West, from which they draw moral support. Instead of isolation single activists or serious punishment, as had been the practice over the past several years, it was evidently determine to strike widely.

So it is, for example, that nine members of an unofficial group set up a year ago to monitor Soviet compliance with the human rights provision of the Helsinki accord on European security are in custody and face serious charges. These arrests were made in Moscow, kiev and Tbilisi, Soviet Georgia, in February and March.

One of the nine is Anatoly Scharansky a 29-year-old computer specialist who had applied to go to Israel and been refusal. This week his family was notified that he is charged with treason, which carries a maximum penalty of death. Scharansky and two other Jews who have not been seized were accused in the government newspaper Izvestia of spying for the CIA at the Instigation of diplomats in the U.S. embassy and with the encouragement of American correspondents.

Another of those arrested is Alexander Ginzburg, who was the manager of a fund to provide financial aid or families of political prisoners with money supplied by exiled author Alexander Solzhenitsyn. In addition, therefore, to charges of anti-Soviet activities, Ginzburg may also stand trial for violating strict Soviet currency laws.

Medvedev contends that the encompassing nature of these arests, touching virtually every notch on the dissident spectrum, reflects the detailed planning of an offensive against all those who as Pravda put it, "cooperate directly with anti-Soviet centers abroad" - in effect, any gernment, organization or individual of whom the Kremlin disapproves.

There appear to be at least four important factors in the Kremlin's decision to mount such a concerted offensive at this time:

This is the year of the Belgrade conference - a perparatory phase begins June 15 - in which governments are to review implementation of the Helsinki accords signed at the summit meeting of 35 European countries, the United States and Canada in August 1975. The Soviets clearly felt that no internal criticism of their compliance on human rights questions could be tolerated because that would appear to be weakness in an international forum - tacit acknowledgement that the Kremlin has not carried out those provisions while it insists that it has.

The surge of dissident protests in Poland, Czechoslovakia, East Germany and Romania alarmed the Soviets, who saw the possibility of a domino effect that could end somewhere in a bloody clash such as in Hungary in 1956 or Czechoslovakia in 1968. Firm action was chosen to head off that danger here adopted measures of varying severity suitable to their own situation.

Ideological sensitivities, always high, are particularly acute this year, the 60th anniversary of the Bolshevik revolution, an occasion for much self-congratulation. Added to that is the announcement of a new constitution containing a redefinition of people's rights and obligations in the Soviet Union - which definitely do not include active political dissent.

President Carter launched a frontal assault in the first few weeks of his administration of the Soviet human rights record. Such moves as the letter to physicist Andrei Sakharov and the reception of exile Vladimir Bukovsky at the White House were regarded here as provovcations and a reflection of charged attitudes in Washington towards detente. If relations with United States are going to be worse anyway, the argument probably went, there is no reason to go gently in settling the dissident problem.

What links all these seemingly disparate points is that the Soviet leadership, which feels profoundly that national prestige is diminished by dissenters, found compelling justification for strong measures that had not been evident in the past few years.

As to how such reasoning works, Medvedev cites an example that took place some time ago but is relevant to understanding the current attitudes in the Kremlin.

"I have been informed," he writes, "that in the period of the loudest campaign in the United States on behalf of free emigration from the Soviet Union, in one of the working groups on the new constitution it was decided to cross out from the draft on citizens' rights a statute on the right of 'free exit and entry to the U.S.S.R. "They will shout that we adopted that point under their pressure,' said one of the Central Committee secretaties supervising work on the constitution."

Given that sort ofattitude at a time shen detente was in its heyday two or three years ago, it is easy to see why with Soviet-American relations at their lowest point in many years, party chief Leonid Brezhnev and his colleagues feel they have nothing to lose - and from their point of view, much to gain. If dissidents cannot speak out and Western journalists or diplomats do not record what they say, as far as the rest of the world is concerned, they do not exit.

Since the early 1970s, at least, the U.S. embassy has assigned one political officer to monitor the dissident scene, an important source of information for answering congressional queries and for helping the State Department analyze Soviet affairs.

The diplomat now in that job is Joswph Presel, who has been in Moscow two years. Presel deliberately went about his frequent contacts with dissidents openly to show that he had nothing to hide, as he certinly would have if he were working for the Central Intelligence Agency.

On March 4, the Izvestia article - which accused Scharansky and two other Jews as well as several who have already emigrated of gathering material for the CIA - named Presel as their contact with the embassy. His predecessor in the job, Melvin Levitsky, now a State Department desk officer, was also attacked.

The allegations have been denied and protests lodged with the Soviet Foreign Ministry. But Presel is now followed intensively by a carload of KGB agents. Embassy sources acknowledge that the job of reporting first-hand what is happening among dissidents is no longer feasible.

While the access of Western correspondents to dissidents has not been physically restricted, there are many more attacks on them in the press. In the past few weeks, present or former correspondents of The New York Times, The Washington Post, Time, the Associated Press, Le Monde, and the Swedish newspaper Daghens Nyhether have been accused of inciting dissidents.

One such article - an interview published in a Moscow evening newspaper with a young Jew who attempted to emigrate and for a time was a dissident activist - said that "foreign correspondents . . . met regularly with those of us whom they thought were the sharpest at cooking up events and facts that could best embarrass the U.S.S.R. They chose the themes for us and told us to demonstrate."

Workers at a large Moscow factory, according to a Soviet source who was there, were instructed to stay late on the day the article appeared and it was read to them aloud.

In another case, a Russian friend (who was not even a dissident) of a departing correspondent told how he had been summoned to the KGB and advised that the reporter was a CIA agent who actually spoke Russian fluently although he pretended to speak poorly. The message was obvious: Stay away from such people in the future.

Such tactics are not novel but many of the old measures that had lapsed are again common.

Hints of anti-Jewishness are perhaps inevitable in a severe crackdown on dissidents, since Jews are central to the emigration movement. The vociferous committees abroad on behalf of Soviet Jews provoke sharp retorts from the Kremlin and when these are in full force, as they are now, the tone is chilling.

A film called "Traders of Souls," for instance, shown twice this winter on Soviet television, concerns the international campaign for Jewish emigration, making it seem subversive, ruthless and corrupt. A host of familiar cliches about the wealth and power of Western Jews are solemly put forth. A shot of a demonstration for Soviet Jews in London is followed by a picture of a fat man, obviously meant to be Jewish, handing out money to the participants.

Sorting out the currently gloomy picture, Medvedev, who is critical of the Kremlin from a liberal Marxist perspective, says that bad as it is, 1977 cannot be remotely compared to the Stalinist terror of 1937 or even the repressions of 1967-68, the tense period around the invasion of Czechoslovakia. But he argues that the dissidents are mistaken if they think pressure on the Kremlin from President Carter will have much beneficial effect.

The United States, he contends, simply cannot induce fundamental changes in the Soviet style of communism and, given the need to survive in a nuclear age, "will not long make defense of human rights in the U.S.S.R. the basis of its policy toward" Moscow.

"Certainly," writes Medvedev, "American propaganda can be used to point out various failings in Soviet society. But if the question is serious, long-term improvements in our society to include and develop democratic rights and freedoms, then the goal can be achieved only by the people"of the Soviet Union. In the year 1977, that objective has plainly receded.