East European governments, long plagued by chronic power shortages, have been following the crisis in Iran with apprehension over their own future oil supplies rather than jubilation at the possible downfall of a pro-Western government.

The reason for their concern, according to Western analysts here, is Iran's emergence over the last few years as an alternative to the region's traditional dependence on the Soviet Union for its energy imports. At meetings of the Soviet bloc's economic grouping, Comecon, the Kremlin has made it clear that, in view of its own needs, it cannot be expected to meet Eastern Europe's rapidly rising energy requirements over the next two decades.

As if to illustrate the problem, much of Eastern Europe has been faced with severe power restrictions this winter--with factories forced to cut production in Poland, schools closed for several weeks in Czechoslovakia, electricity cuts of up to eight hours a day in Yugoslavia, and somewhat less drastic reductions in Romania and Bulgaria. In Hungary, gas prices have been increased 25 percent and a long-term energy saving program has just been approved.

In most cases, the official reason given for the disruption has been the unusually severe winter which depleted hydroelectric energy reserves in Yugoslavia and Romania and disrupted the transportation of vital coal supplies in Poland. The real reason for the crisis, however, lies deeper: Eastern Europe is still coming to terms with the energy crisis that hit the West five years ago.

A complicating factor has been the suspension of Iranian natural gas exports to the Soviet Union as a result of the current turmoil and strikes in Iran. East European diplomats have indicated that this has led to a reduction in Soviet energy supplies to Eastern Europe.

Whatever the short-term effect of the Iranian upheavals on Eastern Europe's current power crisis, their significance for the long-term economic prosperity of the region is considerable. Ironically, in view of the contrasting ideologies of the governments involved, this is largely due to Shah Mohammad Reza Pahlavi's intensive personal diplomacy in Eastern Europe during the last 10 years.

Despite the fact that the Communist Party has been banned in Iran since 1949, the shah paid considerable attention to developing good relations with the states of Eastern Europe. He has visited every country in the region at least once, and Poland and Bulgaria three times.

As late as last June, the shah was being described by the Hungarian press during an exceptionally cordial visit to Budapest as "a clear-headed economist, a supreme manager, and a purposeful and optimistic man." He received red carpet treatment everywhere he went and was installed as a doctor of law at Budapest University, with Empress Farah being declared a doctor of philosophy.

The reason Eastern Europe's Communist rulers fell over themselves to play compliments to the shah, and are only now beginning to revise their opinions, is energy. It is expressed in the striking statistic that between 1975 and 1990 the region's fuel imports are expected to expand three-fold to 50 percent of total energy requirements.

While the Soviet Union was Eastern Europe's exclusive supplier of crude oil, the Soviet Union's share in the market is expected to drop to 75 percent by 1980 and even less in 1900. At the same time its prices are rapidly increasing.

Under the shah's guidance, Iran became one of the most attractive of alternative energy sources for Eastern Europe. Iran has managed to tie itself into the region's expanding oil and natural gas supply network and has been more willing than other members of the Organization of Petroleum Exporting Countries to agree to barter deals.

In November 1976, for example, Czechoslovakia signed a 20-year contract with Iran for the delivery of natural gas worth $2.5 billion -- the biggest deal ever concluded between Czechoslovakia and a non-socialist country.

The gas was to be delivered, under a swap arrangement with the Soviet Union, through a special pipeline known as the "Iranian line" which is scheduled to become partly operational by 1981. The pipeline, which will run the length of Czechoslovakia from the Soviet to West German borders, will also feed natural gas to Western Europe.

Meanwhile, Iran also has secured an interest in the 110-mile Pan-Adriatic pipeline from Krk Island off northern Yugoslavia which will carry up to 170 million barrels a year for Yugoslavia and 35 million barrels of oil each for Czechoslovakia and Hungary. Yugoslavia has signed a contract with Iran for 7 million barrels a year -- a third of its annual requirements.

All these contracts help explain why East European countries have taken a wait-and-see attitude toward the Iranian revolution. As a Western diplomat in Hungary remarked: "They are playing it very cautiously, wanting to know which way the wind is blowing before deciding who to support."

Taking their cue from the Kremlin.East European countries are now beginning to publish sympathetic articles about the Shah's archenemy, Ayatollah Ruhollah Khomeini, depicting him as anti-Western and the precursor of a popular revolution. But the general tone of the reports remains cautious and factual rather than jubilant, reflecting the deep ambivalence in Eastern Europe towards Iran's uncertain future.