Soviet President Leonid Brezhnev's long-awaited summit meeting with President Carter in Vienna this week is unlikely to achieve any major breakthroughs on the serious issues straining bilateral relations, although it should create the appearance at least of better times ahead.

The official Soviet media has hailed the approaching meeting as a sober triumph of the two governments' commitment to strategic arms control, but it has carefully refrained from suggesting in any but the most general terms that the talks could lead to progress elsewhere.

In this respect, the Vienna meeting occupies a very different place in the soviet leadership's assessment of the potential for achievement than did the 1972 Moscow meeting between Brezhnev and President Nixon, when the SALT I agreement was signed. At that time, the Soviets hailed the talks as the start of genuine detente, ushering in a fundamentally new relationship between Moscow and Washington.

Seen from here, the Soviet restraint is justified, for the Kremlin currently confronts a variety of unpleasant or unsetting factors in its relationship with Washington which the Carter-Brzhnev meetings cannot change to Moscow's satisfaction.

Among them are these:

Carter's decision last week to develop and deploy the MX strategic nuclear missile as a counter to continued Soviet missile improvements. The Communist Party newspaper Pravda today in a short dispatch called the president's decision "unjustified and dangerous." An earlier account, written before the president's decision was made public, said deployment of the MX would be a violation of the spirit of the new Strategic Arms Limitation Agreement (SALT II) to be signed in Vienna.

Substantive Soviet comment on the MX decision, when it does come, is sure to be angry, threatening a new round of Soviet countermeasures. The White House has said that Carter will explain the reasons for his decision to Brezhnev in Vienna, but that will be seen here as a week palliative for grim escalation in the arms race.

Successful diplomatic efforts by China to forge new ties with the United States, Japan and the capitalist West at the expense of the Kremlin, increasing ever-present Soviet fears of "encirclement" by ideologically hostile nations.

The Soviets last week played their own small "China card" by agreeing for the first time' since the feud with Peking began almost 20 years ago to negotiate with the Chinese without preconditions. But American aims at continuing improvement in relations with China, although a spur to Moscow to attempt to compose its differences with its Communist rival, are unlikely to be affected either by the new Soviet initiative or the Vienna talks.

A new spurt in arms spending by the NATO countries to help neutralize the Soviet Union's painfully achieved conventional military superiority in Central Europe. The Soviets have reportedly proposed direct Soviet-American negotiations on troop reductions in Europe and Brezhnev seems likely to pursue this at vienna.

But the issues here are complex and fueled by mutual suspicions not susceptible to solution in the relatively brief amount of time the two men will have together. Soviet officials in recent days have expressed private dismay that West German Chancellor Helmut Schmidt in his talks with the president last week gave general backing to increased military preparadeness in Western Europe.

The SALT II treaty Brezhnev and Carter will sign will become hostage to the U.S. Senate, where ratification is considered unsure. This situation confronts the Kremlin with the unusual task of explaining to millions of party faithful how Brezhnev's name could be attached to something that may be rejected, with all the weighty implications for Soviet prestige such a reversal would carry.

The Soviets have been struggling for weeks to explain publicly the difficult facts of the American democratic process, in which the Senate may not follow the president's wishes in adopting the treaty - a lack of discipline unimaginable here.

Pravda on Thursday described the workings of theSenate in a notably low-key manner and observed: "It's harder for U.S. presidents to achieve a compromise with the Congress in recent eyars even though the master of the White House and the (congressional) majority belong to one and the same party. To a certain extent, relations between legislative and executive powers are substantiated by the American political doctrine of 'separation of power.'"

It went on to say that Carter frequently must rely on opposition Republicans to approve his initiatives, that he confronts a Congress intent upon asserting its powers following the Vietnam war and the Watergate scandal, and that "the Senate must give advice and consent' to the president when the foreign political course is determined."

That Pravda would find such neutral terms to describe the president's dilemma is seen here as sign of genuine, high-level concern that the expected Senate debate on SALT II be explained in a credible way well in advance of its start, when its progress will be monitored here via the Western radio stations millions are thought to listen to.

At the same time, the article made clear the Soviet view that the treaty will not be ratified only if Carter himself fails as a leader. It quotes several senators as saying as much to the Pravda man in Washington.

The list of irritants and questions that cannot be settled in Vienna is much longer. It includes such matters as improved trade relations, favored by Carter but still much debated in Congress; involvement of Turkey in the SALT verification process; extension of the mandate for the United Nations Emergency Force in the Middle East, which the Kremlin opposes; and internal Soviet handling of human rights activists.

The change in Brezhnev's health in the years since the last U.S.-Soviet summit in late 1974 also is a factor seriously impinging on the Vienna sessios. At 72, the Soviet president and Communist Party general secretary is considerably slowed from his heyday as chief Kremlin negotiator with Nixon and secretary of state Henry Kissinger.

In Sessions with other heads of state this year, the Kremlin chief has read from prepared papers, and has avoided substantive extemporaneous conversation, confining himself to jovial quips and asides drawn from his vein of earthy Russian humor.

It is likely that the conversations between the two heads of state will touch on many of these issues, but solve few of them.

The Soviet awareness of his has contributed to the reserved and "correct" attitude being taken here toward this latest affair of state between the world's dominant powers.