A STORY was making the rounds in Yugoslavia last year after the funeral of President Tito's heir-apparent, Edward Kardelj. Moscow was represented at the rites by its ambassador to Belgrade, while the United States had sent a high-powered delegation from Washington. Why, someone asked the Russians, did they ignore the passing of Tito's deputy? "Never mind," the Russians were supposed to have replied. "When Tito dies, we will all come."

Although apocryphal, the story touches one of the most sensitive issues of Yugoslav life. Now that Tito has left the scene, will the Russians make a grab for the one country that defiantly escaped their clutches?

Put it another way, the question is: Will Tito's successors be able to sustain his course -- a course that over the past 35 years imposed a degree of coherence on a country of six constituent republics, five nationalities, four official languages, three religions and two alphabets?

That such a question should be weighed seriously in foreign chanceries is a tribute to the man who brazenly forged a modern state and led it down a unique path between East and West, exploiting both. During the Cold War, Tito turned his balancing act into a form of art.

Over the years, he received more than $4 billion in various forms of aid from the United States, without giving much in return. His view of America, former ambassador George Kennan said privately, was that of "a milk cow, not a bull -- all tits and no horns."

Stalin's successors also offered Tito economic support to lure him back into the fold. Today, the Soviet Union is Yugoslavia's number one trading partner, although Titoism remains a poisonous ideological challenge for Moscow, a heresy which must be crushed or contained. The relations between the two countries, a senior Soviet diplomat has said, "are cordial and insincere."

But Tito's brillant balancing act was also a trap he built for himself and his successors. Both his power at home and his prestige abroad depended on Yugoslavia's unique international standing: a part of the communist world, yet independent -- definitely not a satellite -- a leader of the Third World, yet on good terms with the West.

Some Yugoslavs suspected that the on-again, off-again process of reconciliaton with Moscow was designed by Tito to insure his personal authority at home by playing often and subtly on the fear of the Soviet threat, and also to provide him with a forum for personal involvement in world affairs. He had involved his country in a game with excessively high stakes, one former Yugoslav diplomat commented: "His talents and ambitions exceeded by far the economic and military muscle of Yugoslavia." Moreover, he was the type of leadership impossible to transfer to a successor, or to the group of successors now running Yugoslavia. t

Since the Yugoslav leader, as Communists, cannot seek security in the West, they are now left with a subtle and intricate diplomatic game.

In a changing international environment, a small country must constantly seek to avoid conflict with a great power -- on the one hand, by making cautious adjustments to defuse tension and, on the other, by projecting its determination that the possibility of conflict is preferable to capitulation.

While politically Yugoslavia lies between East and West, in a social and spiritual sense it has become part of the western industralized world. Its entry into Europe has demonstrated the country's backwardness and increased its resolve to overcome it.

Paradoxically, when Tito set out after World War II to modernize his reluctant peasant country, he had to do so by force. Now, 35 years later, the Yugoslavs clearly want more rapid modernization, but their rulers are holding back on reforms for fear that these would spell the end of the Communist monopoly on political power.

Tito's experimentation and bending of Marxism to fit his needs have left Yugoslavia a country without an ideology. A hardening antipathy to Soviet-style communism coexists with a broader widespread acceptance of socialism of the type practiced in Scandinavia. Apart from this general commitment to socialism, Titoism has long since been reduced to a set of practical policies -- independence, nonalignment, self-management, market socialism and open borders. This, in fact, is Tito's legacy.

It is also Yugoslavia's problem. It would be impossible today -- short of a cataclysmic civil war or direct Soviet intervention -- to turn Yugoslavia into a "people's democracy" of the East European type. And it is equally impossible for Tito's successors to turn the country into a western democracy. So, cornered, they will probably have to perpetuate Titoism without Tito to protect their own power.

Even if they were to embark on meaningful reforms, any such move born of insecurity could provoke an active Soviet policy of subversion. The Russians, who lack an outlet to the Mediterranean, view Yugoslavia as a valuable piece of strategic real estate. But they are unlikely to resort to military intervention, because such action could prove both costly and protracted.

After the passing of charismatic leaders, countries invariably turn inward. Big foreign policy dreams normally fold like an accordion. Lesser men get bogged down in big domestic problems. And Tito has left his heirs with a most difficult unresolved question: How much individual freedom can be permitted?

He grappled with it for years, sidestepping it in many ingenious ways, claiming that what he wanted to achieve was a real kind of freedom that does not exist either in the West or the East: "direct democracy" at the local levels of self-managed socialism.

He took a series of half-measures -- consumerism, the open-borders policy, ethnic rights, freedom of movement, economic integration into Western Europe -- all of which were to divert attention from the central question. Whenever there were stirrings of unrest in the country, he was shrewd and sensitive enough to perceive them and to incorporate them into his policies, diffusing some of the restlessness.

But, more significantly, he was the man who knew how to handle both the Russians and the Americans. He turned his country of 22 million into an independent force in international affairs.

Tito's heirs will not have the charisma or reputations to sustain the Titoist illusion -- the illusion that something unique and new has emerged at the junction of yeast and West Europe, that new Marxist truths have been discovered. In Yugoslavia one is aware, perhaps more than in other communist countries, that communism is a mosaic of half-truths, that it was based on a misunderstanding of 19th century Western European ideas transplanted into the backward world of Slavic Europe in the 20th century.

The genius of Tito lay in his obliviousness to ideological scholasticism and his obsessive insistence on practical policies of development. He sought to bring about a cultural renaissance and an industrial revolutions in a mere three decades. His was an era of innovative mimicry. His heirs now must deal with a country that has assimilated, however imperfectly, the ideas and technology of Europe. And Tito's old magic, with its power to move the people, will no longer be there.