Eastern European leaders with long and secure tenure are striving to assert greater authority in their foreign and economic relations during a protracted phase of paralysis in Soviet policy and leadership.

The absence of a dynamic personality heading the Kremlin in recent years has contributed to a growing sense of national identity in Eastern Europe and emboldened Hungary, East Germany, Bulgaria and Romania to show more independence in dealing with the West, according to Eastern Bloc party officials, academics and journalists.

While rumors circulate about the ill health of Soviet President Konstantin Chernenko and the possibility of a fourth leader in Moscow within three years, the communist party hierarchies in several Eastern European states have demonstrated a remarkable degree of stability and continuity.

Hungary's Janos Kadar and Bulgaria's Todor Zhivkov have ruled for three decades. Romania's Nicolae Ceausescu has held power for nearly 20 years, while East Germany's Erich Honecker has steadily enhanced his dominance since assuming leadership 13 years ago.

Increasingly, these communist party chiefs appear to be capitalizing on their enduring stay at the top to attract greater popularity at home by pursuing initiatives that emphasize national interests more than strict adherence to Moscow's directives.

Few doubt that such experienced leaders have been able to conduct more autonomous policies with greater confidence and security than younger men who could not have built up their stature and reliability both at home and with Moscow.

Yet the congruence of several Eastern European countries pursuing more independent ways at the same time poses the question of whether the Soviet Union will be forced to make longterm concessions to a general trend in the Eastern Bloc for wider autonomy over national affairs, if only to avert future rebellions there.

In the past, Moscow has managed to cope with one challenge every few years: East Germany in 1953, Hungary in 1956, Czechoslovakia in 1968 and Poland in 1980.

The gradual emergence in the Eastern Bloc of more individual foreign and economic views based on national considerations may compel future Soviet leaders to consider relaxing pressures because of the continuing high economic as well as political costs of imposing rigid hegemony, sources in the region say.

But a conflicting factor weighing in the balance may be a concern within the Kremlin that any relaxation might only breed more virulent efforts to break Soviet control.

At a time when the Soviet Union appears to have adopted a fortress mentality and is intensifying its propaganda attacks against the United States and West Germany, the predominant mood in Eastern Europe clearly favors rebuilding detente and dialogue with the West, including new breakthroughs in arms control as well as expanded trade and financial contacts.

Only the Polish and Czechoslovak governments have demurred from the current quest to develop better channels with the West.

Warsaw appears too consumed by the simmering conflict with Solidarity and Prague too traumatized by the ill-fated revisions of 1968 to consider serious deviations from the Soviet positions.

A clear sign of rising Soviet anxiety over the detente-minded allies was reflected in the intense pressure brought to bear on Honecker to call off his planned trip to West Germany later this month.

West German officials say they believe, in retrospect, that one of the major factors behind the scuttling of the trip was that the Soviets came to believe the immense publicity surrounding Honecker's coming to West Germany had transformed the event into a challenge to their prestige and control over Eastern Bloc states.

"When the trip assumed those proportions, Honecker realized that whatever he could get out of the visit could not outweigh the nasty repercussions of wounded Soviet pride," said one of Bonn's top Soviet Bloc specialists.

Nonetheless, Honecker quickly expressed his determination to press ahead with a policy of dialogue with West Germany in order to "limit the damage" to East-West relations caused by the deployment by the North Atlantic Treaty Organization of new nuclear missiles in Western Europe.

No matter how badly he may have wanted to visit West Germany and see his boyhood home in the Saarland, Honecker, in the view of analysts, may have decided it wiser to avoid a showdown with Moscow now in order to gain more breathing space for future overtures to Bonn.

Other Eastern European leaders still seem intent on fulfilling trips to the West while Chernenko stays home. Bulgaria's Zhivkov is expected in Bonn on Sept. 20 and Romania's Ceausescu is scheduled to go there Oct. 15. Hungary's Kadar is to visit Paris this fall.

Such trips have proven highly popular among some citizens of Eastern Europe, who see state visits of their leaders abroad as proud symbols of distinct national identity. The national roles of Eastern European countries have largely been inhibited over the years by Soviet hegemony.

The popularity accorded leaders who venture, if cautiously, to promote national interests at the risk of dismaying Moscow is also becoming an important factor in establishing political support at home.

The rapprochement with West Germany, for example, appears to be backed by party officials and government technocrats as well as the overwhelming majority of people in East Germany.

More than before, in the view of analysts, Honecker's future strength will be measured not only by his loyalty to Moscow but also by how well he can establish better economic ties with the West, and his ability to reconcile these two constituencies will determine his political destiny.

Similarly, observers say, Ceausescu's rule, frequently criticized as autocratic and nepotistic, has become more tolerable in the eyes of many Romanians because of his defiance of Moscow on defense and foreign policy issues.

He has attempted to establish a role as bridge between East and West, has served as a broker of Middle East peace plans and has spurned Soviet demands to boycott the Olympics.

The search by Eastern European countries for ways to insulate themselves from the tensions between Moscow and Washington and the growing tendency to go their own way in perpetuating friendly ties with Western Europe has intensified in the last four years.

Ever since the gravity of Leonid Brezhnev's illness became evident, Eastern European countries have recognized that they have to undertake their own initiatives in bolstering vital trade and financial ties to the West that became critically important to their economies during the 1970s.

The Soviet Union, and to an extent its closest ally, Czechoslovakia, have instead turned inward while awaiting the longterm resolution of the Kremlin's succession crisis.

The cultivation of western contacts has persisted in spite of Moscow's admonitions because, one Hungarian party official said, the struggle for dominant power in the Kremlin is likely to go on well after Chernenko dies because his successor will require much time to establish a strong power base.

"We cannot afford to wait that long, because our economy requires reforms that will be necessary to improve living standards in the future," the Hungarian said.

The Hungarian view, increasingly supported by countries like East Germany and Bulgaria that once echoed the prevailing dogma in Moscow, is that the future of Eastern European economies dictates reform and wider trade with the West -- the sooner the better.

"International tensions do not sweep away internal problems," said Gyula Gyovai, director of Hungary's Institute for International Affairs. "The leadership changes in Moscow have occurred at high speed, and nobody could have predicted that.

"But what has not changed is the growing need to pay more attention to economic efficiency. I think you are going to see more articles in the Soviet press in the future about the need to improve management and the quality of services in the Soviet Union, more because of the economic pressures than the desires of one man."

Throughout the Soviet Bloc, the problems of the transition of power remain acute, though perhaps not as much as in the Soviet Union today.

"How to have a smooth change of leadership remains perhaps our biggest political problem in the socialist bloc," said Tibor Petho, editor-in-chief of the official Hungarian daily Magyar Nemzet.

He acknowledged that the stability that Hungary and some other Eastern European countries have enjoyed in recent years derives largely from the consistent, steady leadership provided by one man over a decade or more -- such as Kadar.

But at some point, probably sooner rather than later, observers say, Eastern European countries will have to face the consequences of a change of generations in the power structure.

"We should provide a greater mix of younger and older people in the top levels of party and government work," said Richard Dvorak, a former Czechoslovak ambassador to Moscow who is now a counselor in the Foreign Ministry in Prague.

"But as for change, maybe it's not so bad to see each country trying to adapt in a different way, at different times. We might be able to learn from each other."