Behind the uncertainties generated by the labor unrest in Poland is a political predicament of the Soviet Bloc that can be described with one word -- energy.

Following the dramatic rise of world oil prices in 1973, the Soviet Bloc sought to shield itself from their impact through modest adjustments and short-term fixes.

But the Polish events and reports of industrial unrest in Romania last week indicate that Eastern Europe is entering the 1980s facing the painful prospect of economic stagnation -- offering little means to meet the rising expectations of its population.

According to diplomatic analysts, the region is under new stresses between governments and people. In turn, there is new economic tension between the bloc nations and the Soviet Union. The analysts say all East European capitals seem jumpy, as if expecting troubled times ahead.

All this comes after a period of tranquility and relative prosperity. Following the 1968 Soviet invasion of Czechslovakia and the 1970 Polish strikes that brought down the government, all East Europeans followed the Soviet lead in giving greater attention to customer goods, real wages and housing. Simultaneously, the advent of detente opened up trade with the West and held out the promise of political relaxation.

Even the 1973 oil crisis brought short-term benefits to the East Europeans. They were getting almost all of their oil from the Soviet Union. Prices were frozen at 1971 levels for the duration of the 1971-1975 five-year plan. Consumer prices held stable while Western economies plunged into recession.

The Soviet Bloc was entering the automotive age. Russians, Poles and even Romanians began producing cars in large quantities. Even as the Soviet Union in 1975 began slowly pushing energy and raw-material prices upward in 1975, things in Eastern Europe were going well.

But then the Soviets introduced a rolling five-year average world price for their energy and the six countries East European members of the Soviet Bloc gradually began to feel the pinch. Once viewed as political satellites, they increasingly became economic dependents of Moscow.

Although they are still getting Soveit oil at about 60 percent of the current world price, the jump has slowed their overall economic development.

The Soviet Union is the world's largest oil producer with over 12 million barrels a day. It is one of the world's largest oil exporters, selling about 3 million barrels daily, more than half of which goes to Eastern Europe. It has been increasing exports to Western Europe to generate hard currency for technology purchases.

Over the past few years, Moscow has pushed its allies to seek alternative sources of oil, for which they have to pay world prices in hard currency. To make matters worse for Eastern Europe, the prices of Western industrial imports have risen while Western countries are buying less from the East.

Short of hard currency, East Europeans have borrowed money in the West. Poland is perhaps the most striking example. When Edward Gierek took power in 1970, the country had virtually no foreign debt. Today it owes Western banks and governments $19.4 billion. It borrowed $4 billion last year alone. Poland has to find $7.1 billion to service its debts this year.

The rising oil prices, coupled with growth declines and lower productivity, have had a profound impact on the region. Yet the fundamental cause of stress is energy.

In 1978, the Soviets provided 92 percent for Bulgaria, 85 percent for East Germany, 80 percent for Poland and 70 percent for Hungary. Romania, an oil producer, is not dependent on Soviet oil but is heavily dependent on Soviet natural gas, as are all other East European countries.

Specific figures for 1979 and the current year are not available, but a Soviet economist recently said that the combined reliance of Soveit energy has already declined and that he expects it to shrink further to about 50 percent by 1990.

According to Western economists who specialize in analyzing Soviet bloc statistics, real growth rates have declined considerably throughout Eastern Europe and have dropped well below the already scaled-down target figures.

There has been a lot of backstage argument in Comecon, the Soviet Bloc economic community, about the price system. But the centrally planned economies are deeply resistant to changes. Only Hungary has attempted to introduce serious economic reforms.

In this context, the Polish labor unrest may be foreshadowing a troubled decade of Eastern Europe. Officials there have privately indicated concern for some time about the economic difficulties and possible political consequences. What is particularly vexing to them in Poland is the speed with which protests against price increases escalated into a clear political challenge to the communist government.

The strikers are now demanding structural changes, including free speech and free trade unions. The rising expectations, one source said, have produced a "me generation" in Poland that wants now what the leaders used to promise for the golden future.

The Soviets and their allies are reported to be extremely uneasy, primarily seeking to prevent the spread of such ideas to the rest of Eastern Europe. Moscow has cast its lot with Gierek in the hope that the crisis will run its course and be settled without violence.

But analysts here believe that only basic economic reforms could provide a basis for a long-term settlement. In this view, a quick settlement, if possible to achieve, would be only temporary.