WAHTEVER THE success of failures of his policy toward the Soviet Union, one point is clear: President Carter appears to have aroused intense anxiety among the Soviet leadership.

The reasons for this anxiety date back to the early days of detente in the late 1960s and early 1970s. Though "detente" has long been a common term in both the Soviet and American political vocabularies, the concept has always been differently understood in Moscow and in Washington.

In the Soviet Union, the doctrine of detente was based on the idea that it would be possible and desirable to achieve limited disarmament and to engage in scholarly, scientific, cultural and commercial exchanges without implementing social reforms or expanding the freedoms of Soviet citizens.

The fear that expanded relations with the West would result in significant penetration of Western ideas into Russian was a serious obstacle to detente in the view of Soviet leaders. Some Soviet liberals, including myself, hoped that detente might actually be accompanied by liberalizing reforms at home, but we were in a minority. In early 1971, Georgi Arbatov, the chief Soviet theoretician of detente and director of the Institute of the U.S.A. and Canada in Moscow, attacked our liberal, pro-detente position as "extremist ideals."

Arabatov was critical of those who favored modest democratization of Soviet society from within. But he personally believed that detente would inevitably result in strong new Western influences in Russia and would eventually bring the Soviet Union many of the advantages enjoyed by Western societies, including freedom. Arbatov approved of Western influence that would force changes in the Soviet Union, but, like many others, he feared that unilateral reforms from within could result in incontrollable pressures of sudden, wrenching changes. In effect, he preferred to leave it to foreigners to force the changes that Soviet society could tolerate.

THe internal debates over detente in Moscow reflected uncertain perceptions of American intentions among the Soviet leaders. During the years I was involved in advising top-level Soviet leaders, I heard three conflicting explanations for America's interest in detente.

According to the first, the United States wanted to ex-acerbate the Sino-Soviet conflict, even to the point of war. According to the second, the Americans wanted to destroy the very basis of the Soviet system by introducting profoundly liberalizing social change as a result of Western influence on Russia. The third explanation offered was that American simply wanted to reduce the nuclear threat to humanity, without regard to the Sino-Soviet conflict or liberalization of the U.S.S.R.

The majority of Soviet experts and interest groups accepted some combination of the first and second explanations. The idea that the United States wanted to ex-acerbate the Sino-Soviet dispute and liberalize Soviet society prevailed among the mass of old apparatchiki of the Stalin school, the Party and its Central Committee, among employes of the KGB's domestic service, the Defense Ministry, the armaments industries and the leaders of military units along the border with China, Mongolia and Afhanistan.

This group not only disapproved of arms control, but, in light of the Sino-Soviet conflict and what these people saw as the American desire to exacerbate it, they favored more arms spending. In 1968-69, the Soviet military-industrial complex was working on the idea of a preventive war against China - an idea that was only abandoned in 1969 by the Soviet leadership.

Supporters of the theory that the West sought to liberalize the Soviet system through detente included the foreign or external branches of the KGB, the Ministry of Foreign Affairs, the General Staff and a number of specialists on the Central Committee staff.

The minority view that the United States was seeking only to reduce the danger of nuclear war was supported by just two groups, and they were at opposite extremes.

The first was a large group symbolized by Andrei D. Sakharov, the nuclear physicist who became a dissident spokesman. These people believed that genuinely relaxed tensions and arms control were only possible if accompanied by real democratization of Soviet society, and therefore strove for both those goals simultaneously.

The group at the opposite extreme which accepted a benign view of American intentions consisted of Brezhnev and a small group of his Politburo supporters and consultants. The Brezhnev group believed that the Soviets could accept modest cutbacks in strategic arms and atmospheric nuclear tests without significantly weakening the U.S.S.R. (The Soviet dente doctrine that emerged in 1969 covered only reductions in strategic arms, not in conventional forces which might be needed against China.)

Brezhnev and his allies also believed that detente could produce Western economic and technological aid which would help the Soviet Union cope with a serious economic crisis caused largely by the costs of the armsrace. They felt that the Soviet authorities could counteract any new Western influences that resulted from detente.

So Brezhnev firmly believed that the balance sheet of detente would remain favorable for the U.S.S.R.

But things are seldom what they seem. A Russian who had left his country in 1968 and returned in 1976 would have found enormous changes caused by detente and the impact of Western visitors and ideas. Illustrations of these changes can be taken from secret, hitherto unpublished Soviet socialogical studies to which I had access in may work:

1) While in 1966 only 2.4 to 4.2 per cent of college-educated Muscovites regularly listened to Western Russian-language radio broadcast, by 1976 (three years after most jamming was stopped) 40 to 50 per cent of the educated population regularly listened to the broadcasts of the Voice of America, the BBC and other Western stations. Ten years ago people rushed home at 6 o'clock to listen to the soccer gsme; today they rish to finish supper before the 8 p.m. VOA "Panorama" broadcast.

2) Exchange programs have had a great impact on Soviet academic and cultural life. In Moscow and Leningrad, Soviet academics have been able to meet freely with Western exchange participants, exchange scientific literature in foreign languages and invite foreign colleagues home without fear.

3) Dissident literature written in Russian and published in the West finds its way back to Russia in ever greater quantities and is extremely widely read. One copy of the dissident writer Vladimir Maximov's book, "Seven Days of Creation," may be read by 500 to 700 people - in other words, to the point of total disintegration.

4) Of a Soviet Jewish population of approximately 2.4 million, more than 10 per cent have either applied to emigrate or have already left. The popular reaction to this is complicated and ambivalent; on the one hand, many people envy those who emigrate and, or the other, resent the government authorities who prevent others from leaving.

5) Cooperative construction projects involving Soviet and Western firms and workers, such as the auto plant at Togliatti built by Italy's Fiat, result in strong Western influence on the Soviet population. The climate of opinion surronding such projects is reminiscent of the skeptical mood of the Moscow intelligensia.

Soviet workers quickly see the difference between their machinery and working conditions and the beautiful technology and high standard of work of the Westeners. Polls showed that in a matter of 3 to 6 months the young patriots who volunteered to work on the "hero project" a Togliatti became disillusioned with their low pay, the bad organization of their work, etc., when compared with those of the Italian workers at the site.

6) The increasing availability of foreign goods results in favorable comparisons with Soviet products. Nine out of ten consumers prefer imported products.

7) The West's ability to get famous dissidents like Alexander I. Solzhenitsyn and Vladimir Bukovsky released from the U.S.S.R. undermines the regime's moral authority.The educated population increasingly perceives such deals as a kind of commercial trade in human beings. Fissures in the Monolith

THE SIMULTANEOUS necessity for cooperation with the West and measures to counteract the effects of that cooperation created numerous fissures in the Soviet monolith.

The 19th Century historian Klyuchevsky observed that Russia has never known struggles between political parties, but instead is used to rivalries between institutions in society. This still holds ture, with a new twist. Detente and the Soviet leadership's response to it evoked struggles both between institutions and within them.

For example, there are completely different attitudes toward detente in the domestic service of the KGB, which is meant to control the domestic population and its contacts with foreigners, and in the foreign ministry and the foreign sections of the KGB, which are responsible for gathering intelligence abroad.

The professional interests of the latter two lead them to support detente. They are able to see first hand what Western life is like; it becomes harder for them to lie to themselves. They are materially interested in detente, because relaxed tensions increase Soviet contacts with the West, which means more trips and posts abroad.

Soviet officials posted abroad receive hard currency. They have ready access to Western films, theathers and books. They save a large part of their salary in rubles to support their families at home.

But, for example, employees of the KGB's internal sections are forbidden to travel abroad, have no comparable material benefits and, this no personal stake in detente.

Another important factor is the emergence of an "opposition" in Russia for the first time in 40 years. Some elements of it are actually organized, and it is heterogeneous: religious and national groups, liberl Marxists, radical democratic groups and others. During the last 10 years, the preparation and circulation of underground manuscripts, anthologies and journals has become much more common. Brehnev's Problems

THE CHANGES in Soviet society which detente helped induce were more substantial than the Brezhnev leadership anticipated, and they caused violent controversity within the leadership over internal policy strategy.

When they first came to power in 1964, Brezhnev and his collegues embarked on a conservative policy, rescinding the social, political and economic reforms initiated by Khrushchev. Brezhnev even allowed a partial restoration of Stalin's tarnished image. Apparently, he felt he could restore the interntaional prestige of the Soviet government if he could bring back some of the order and discipline of Stalinist times which Khrushchev had allowed to crumble.

This was especially clear in the economic field, where the Brezhnev leadership decided to abandon all flirtations with decentralization of the enormous, unwieldy economy. These leaders were not ready to accept the opinion of many unofficial experts that the real cause of Soviet economic problems was excessive centralization and it consequences - the absence of initiative at lower levels, disinterested workers, low-quality production, etc.

Premier Alexi Kosygin and some others in the leadership favored internal reforms, particulaly decentralization, to improve the economy. But Brezhnev led the Politburo in the opposite direction. Their decision to overrule Kosygin on this issue became an important reason for Brezhnev's ultimate support for detente.

This was the case because Brezhnev and his supporters had decided that the economic crisis could be dealt with by aid (credits and technology) from the West, instead of internal reform, which seemed too risky to them.

In other words, Brezhnev and his allies wanted trade with the West to allow them to avoid any alternation in the domestic status quo. Thus, Soviet detente doctrine contained both a peaceful goal (increased East-West trade and cooperation) and a military threat (Western aid was meant to allow the Soviets to sustain their high level of arms spending).

According to Soviet economists with access to secret statistics, the major reason for the Soviet Union's economic difficulties is the fact that 60 per cent of Soviet enterprises are engaged in production for the armed forces. This creates an acute shortage of consumer goods and mass poverty among the people.

If credits and most-favored-nation status had been granted while the Soviets preserved their economic status quo, the result would have been a freer hand for the Soviet leadership to maintain or expand arms expenditures.

As it turned out, Brezhnev had miscalculated. He was banking on Kissinger's repoeated assurances that Nixon, his position strengthened by improved Soviet-American relations, would ensure passage of the trade bill granting credits and most-favored-nation status. The official transcripts of the Brezhnev-Kissinger tete-a-tete show that Kissinger repeatedly assured Brezhnev that Nixon was a reliable partner who knew how to keep his word.

Brezhnev's real mistake, however, was not so much that he trusted Kissinger and Nixon, but that he believed America would give him trade benefits despite his reactionary domestic policies.

Understanding the American political mentality has long been a problem for the Soviet leaders and the experts who advise them. I recall how, only a few days before Nixon's resignation, Brezhnev's chief foreign policy adviser, A. Alexandrov-Agentov, believed that he could easily survive his Watergate difficulties. Brezhnev and his colleagues were even prepared for Congressional approval of the Jackson Amendment, which barred credits and M.F.N. status unless the Soviets allowed freer emigration.

Kissinger put the emigration issue subtly in his negotiations with Brezhnev. He spoke of giving the U.S.S.R. credits and trade privileges as compensation for "the brain drain" (i.e., the loss of educated Jews to Israel), or as payment in advance for mutual trust. Despite its glibness, this formula was seen by Moscow as thoroughly exemplary.

But Jackson proposed a cruder bargain: credits and trade for a fixed number a Jewish bodies. In Moscow, this appeared to be a crude insult, not only to conservatives, but even to liberal, pro-detente elements. As Alexander Shelepin - Brezhnev's most serious opponent in the Politburo in 1974-75 - argued at the time, to make a deal with Jackson on his terms would amount to accepting the selling of human beings, an unacceptable affront. A Political Virus

IN THE END, political diehards in Washington who supported the Jackson Amendment were unconsciously helping their conservative counterparts in Moscow by giving them a cause around which to unite to defeat the Brezhnev doves.

Every Soviet leader's sneeze may not be important, to paraphrase President Carter, but it is extremely important to know what caused "illnesses" of his sort Brezhnev suffered from December, 1974, until April, 1975. In fact, that illness was partly a real health problem, partly a political virus.

After the passage of the Jackson Amendment and the furor created by publication of Kissinger's letter to Sen. Jackson (in which the Secretary of State promised on Russia's behalf that more Jews would be permitted to emigrate), Brezhnev's political position deteriorated as did his health. He retreated to his palatial dacha in Zavidovo, outside Moscow, and passed the word to his colleagues that, if they felt it was time for him to retire, he would do so.

Shelepin, meanwhile, began lobbying his colleagues. The former head of the KGB took the position that Brezhnev's detente had failed and it was time for a new course.

Shelepin suggested that a new Soviet policy could be signalled to the world if the U.S.S.R. sent "volunteers" to Portugal, on the model of Soviet aid for an Republican side in the Spanish Civil War nearly 40 years before.

Brezhnev, operating from his dacha, tried to counter Shelepin. Probably with the help of others, he came up with a compromise idea - the use of Cuban troops in Angola.

Eventually, Brezhnev and his compromise prevailed. The Politburo accepted the Angola idea, and, on April 16, the Soviet press announced that Shelepin was retiring from the leadership. Soon afterward, Brezhnev's "illness" ended, and he reemerged in an obvious public role.

So the real response to the Jackson Amendment was not the Soviet Government's renunciation of the 1972 trade agreement which followed adoption of the amendment, but rather the adventure in Angola.

The Soviet reaction to the Jackson Amendment was the first crisis of detente, from Moscow's point of view. The abrupt collapse of the dream the significant economic aid would be forthcoming from the West and the increasing impact of Western ideas inside the U.S.S.R. intensified the struggle between "hawks" and "doves" in the Soviet leadership.

The second crisis in detente for the Soviets seems to have occurred early this year. It was brought about, I believe, by Carter's first hard-line gestures on the issue of human rights.

Carter's decision to send a letter to Andrei Sakharov through the American Embassy, and then to meet personally with dissident Bukovsky, were perceived by the Soviet leadership through the filter of stereotyped Communist ideology and the historical traditions of the Soviet revolution. Through that filter, Carter's moves must have looked ominous.

Brezhnev and his apparatus may see Carter as somehow comparable to Lenin in the early '20s, when he addressed opposition movements in other countries over the heads of their leaders, hoping to set off a world-wide revolution.

Brezhnev and his collegues may see Carter as a Bolshevik of the Leninist type - but in his case the goal is not revolution, but the imposition of the American standard of freedom over the globe, including in Russia.

If the Soviet leadership saw the Nixon-Ford-Kissinger policy as defensive and benign, then it now apparently perceives the Carter administration's policies not only as punishment for Soviet violations of detente in Angola, but actually as the rejection of detente as it has been understood.

Carter's human rights offensive must have seemed in Moscow a continuation of the spirit of the Jackson Amendment, the goal of both being liberalization of the U.S.S.R. As a result, Carter has probably confirmed the opinion of those groups who felt from the beginning that the United States sought to impose an unacceptable degree of liberization as its price for detente with Moscow.

It appears that a new coalition coverged behind a new, more conservative policy. Only such a colaition could result in the present active struggle against the previous "damage" caused by Western influences.

Evidence of that struggle is easy to find in the renewed (though more subtle) jamming of Western radio stations, confication of dissident literature, reduction of emigration, recent renewed harassment of Western exchange students and new obstacles in contacts between Western journalists and Soviet citizens. Linking dissidents publicly to the CIA also helps engender a fearful atmosphere. Backyards to Conservatism

BREZHNEV has now reached a political dead-end. He had wanted to use detente to strengthen the international authority of the Soviet regime and to improve the domestic economic situation.

Now Brezhnev has two remaining alternatives. He could acknowledge the failure of his detente policy, but the intensification of repressions that would follow would sooner or later condemn him to removal from office at the hands of the moderate centrists. Or he could accept the new American definition of detente, which seems to demand more liberalization within the U.S.S.R. as the price for ecnomic help.

Tragically the majority of the present Politburo is incapable of bold political action. No matter what policy reformist Politburo members would lke to pursue, they cannot expect to see these reforms consummated during the short time left to them. Of the 14 Politburo members, nine are over 70, three are over 65 and only two are under 60.

The aging Politburo favors the status quo, not reform. They wanted detente so they could avoid rocking their own boat, but found themselves instead on a rather choppy sea. To calm the waters, they have looked backwards toward conservatism, trying to strangle their own offspring, detente.

The ultimate irony may be that conservative policies in no way lead the Soviet Union to a solution of its basic problems. Because of the chaos of Soviet management and the unsophisticated state of the Soviet economy, the Soviet leaders - either this generation or the next - will have to find ways to limit the arms race and arms spendings, even if they don't really want to.