WITH AN IMPORTANT meeting of the Communist Party central committee about to take place, the new leadership in Moscow has charted a radically new course for Soviet foreign and domestic policies.

The changes have been signaled in the ritualistic and little-noticed slogans that the Soviets publish just prior to their two major national holidays, the Nov. 7 anniversary of the revolution and the May Day holiday today. To a Western eye these slogans are routine political boilerplate. ("Peoples of the World! Give a Decisive Rebuff to the Aggressive Intrigues of Imperialism. . .") But in fact they contain important political information, especially when compared to the slogans of past holidays. And the latest slogans, published in mid-April, represent a stunning departure from the Brezhnev era.

The new list contains nearly 40 percent fewer slogans than last year's. But more important than that, many of the traditional goals repeatedly enunciated by the Brezhnev leadership have simply been dropped, as though they are no longer of great significance to the new leaders. The result is a list that suggests sharply reduced Soviet ambitions in both foreign and domestic spheres.

Moreover, the new slogans reveal an important structural change in Soviet priorities. Traditionally, the slogans on domestic issues came first in the list, but this time the foreign policy issues come first. Andropov may believe he can only solve the big domestic problems he faces if he can first resolve important foreign policy issues. More specifically, this new arrangement suggests that an overheated arms race has handicapped the Soviet economy, and that Andropov wants to somehow bring it under reasonable control.

This reversal of foreign-domestic priorities also has implications for the Kremlin power struggle. Putting foreign policy first means giving preeminence to Andrei Gromyko, the foreign minister, who was recently given the additional title of first deputy prime minister. The new slogans may be a tipoff that Gromyko is now the most likely successor to Nikolai Tikhonov, the 78- year-old premier who seems to be on the outs in the Andropov era.

In terms of Soviet policy, the new foreign policy slogans are fascinating. In recent years it has been standard to include specific slogans spelling out Soviet support for favored clients and guerrilla movements -- for example, Afghanistan, Ethiopia, Vietnam, Cuba, Laos, Cambodia, Angola, Mozambique, Nicaragua and the Salvadoran guerrillas. But in the new slogans, all specific references to these have been dropped. In their place are general statements of support for the peoples of Asia, Africa and Latin America

This change suggests that we should anticipate a more flexible Soviet foreign policy in the months ahead. Conceivably, Andropov is prepared to pull back from exposed positions in some of those countries that were named in previous slogans but dropped this time.

On the other hand, two areas of the world are still mentioned specifically -- the Middle East and southern Africa. But here, too, there are changes. The Soviets have reformulated their approach to the Middle East in a seemingly minor but extremely significant way.

Six months ago a slogan called for "an end to Israeli aggression against the Arab peoples." The new slogan calls for "an end to Israeli aggression against Arab countries." The change is important because the Palestinians are a people, not a country. The new slogans suggests a downgrading of the Palestinian problem. In the new list an old slogan is repeated -- "The just cause of the Palestinian people will prevail" -- but there is no reference to the creation of a Palestinian state. The new slogans demand the withdrawal of Israeli troops from Lebanon and from "other Arab territories," but there is no explanation of which other territories.

Domestic policy formulations have also been changed radically. For example, there are no slogans calling for completion of two of the biggest industrial projects now under way in the U.S.S.R., both top priority "crash" undertakings: the Baikal- Amur railway in Siberia, and the pipeline to carry natural gas from Siberian fields to European Russia and Western Europe. In the Brezhnev era no other projects received more national attention than these two.

This doesn't mean either project will be canceled. But it does imply a dramatic reordering of national priorities, a hint that seems to be confirmed by the fact that the general slogan calling for the development of Siberia has also been dropped.

The amount of capital that should be devoted to Siberian development has long been a subject of controversy inside the Soviet elite. In his recent article on the 100th anniversary of Karl Marx's death, Andropov himself hinted that investing heavily in Siberian development has created difficulties for the economy. By dropping references to these projects in the new slogans, the leadership may now be signaling the beginning of a new era of austerity generally.

The new slogans also signal fascinating political changes. Traditionally, at the very outset the slogans emphasized the importance of the Communist Party as an insitution. Surprisingly, on the new list this point has been moved to the very end of the list. Even more unusual, the regular appeal to strengthen the Soviet constitution and to strengthen elected governing councils (Soviets) as political institutions precedes the appeal to strengthen the Communist Party as a political institution.

This is an echo of the brief period after Joseph Stalin's death in 1953 when Stalin's first successor, Georgi Malenkov, tried to make the state administrative machinery the leading political institution, while downgrading the party's importance.

Perhaps we are now seeing the emergence of a "national security coalition" composed of Andropov, Gromyko and Defense Minister Dmitri Ustinov, which will now try to subordinate the party apparatus (which they don't fully control) to the state machinery that is firmly in their hands. In such an arrangement, the army could emerge as a leading -- perhaps the leading -- force. If something like this is the Andropov group's goal, it would be natural for them to try to revive the Soviets as a counterweight to the party.

Slogans are not the same as policies, and it remains to be seen how these startling changes in the May Day slogans will be transformed into practical decisions. But these changes are tantalizing, and in a system that depends heavily on formal rhetoric, they cannot be dismissed.

Conceivably the new slogans signal that Andropov wants to move the Soviet Union away from adventurism, and more toward a status quo, balance-of-power approach to international affairs. We may now see a considerably lower Soviet profile, particularly in the Third World. The slovans also suggest that arms control agreements are a top priority.

It seems a fair guess that for Andropov, the first national priority now is to save the Soviet economy from imminent disaster. The Soviets' global adventures of the last 30 years have undeniably undermined the country's economic strength, even in spite of its great growth.