WHEN a Solidarity-led government first was proposed in Poland last week, a Soviet spokesman voiced concern. He reminded the anticommunist movement to ``take into account the fact that Poland is a member of the Warsaw Pact.'' But there were no warnings, no threats. Instead spokesman Yuri Gremitskikh, reminded questioners that ``the Polish people must solve their own problems.'' Moscow, he added, ``would not interfere in the internal affairs of that country.''
The reaction underlines the ambiguous Soviet role in Eastern Europe. Gone is the old imperial hold cemented by Moscow's interpretation of socialist ideology. Under Mikhail Gorbachev, the Soviet Union champions change. It accepts a Solidarity-led government in Poland and a multiparty system in Hungary, while prodding the region's hard-liners ever so gently into accepting change.
At the European Parliament this July, Mr. Gorbachev even renounced the so-called Brezhnev Doctrine which defended the Soviet right to intervene militarily in Eastern Europe whenever ``socialism was threatened.''
Limits to reform
But would the Soviets permit a Communist Party to step down from power? In Poland, Communist President Wojciech Jaruzelski continues to hold sway over foreign policy. Could an ally withdraw from the Warsaw Pact? Solidarity promises to respect the postwar alliance system.
Soviet officials themselves do not seem to know just how far they are prepared to permit allies to go. In an interview earlier this year, Oleg Bogomolov, one of Gorbachev's chief advisers on Eastern Europe, called such questions ``hypothesis.''
``Making predictions,'' he said, means going down a slippery path which is usually wrong.''
Analysts however suggest that Gorbachev will continue to bend without breaking the Soviet hold over Eastern Europe. He will give the East Europeans more room for maneuver. But he will not let them threaten Soviet security interests, for example by pulling out of the Warsaw Pact.
Bullying allies is bad politics for Moscow, Soviet and East European officials and dissidents agree. It would cut into the wave of goodwill generated in the rest of the world by the new pragmatic, peaceful Soviet foreign policy. And it would destroy the momentum toward arms control in Europe built up by recent Soviet troop cuts.
``Everybody here knows that we need good neighbors, not satellites in Eastern Europe,'' says Yuri Mitiunov, a leader of Moscow's Democratic Union, an unofficial opposition group. ``This is the only way of avoiding a tragedy.''
By ``tragedy,'' Mr. Mitiunov means another convulsive upheaval, that would represent a serious threat to Gorbachev's own reforms, even his hold on power. In his Monitor interview, Mr. Bogomolev stressed Moscow's worry about ``instability'' in Eastern Europe, and made an oblique call for talks with the West to prevent such a disaster.
``The No. 1 Soviet goal in the region is stability,'' says a Western diplomat in Warsaw. ``Gorbachev wants to be left in peace and not have to worry about his external empire.''
This desire for stability translates into a reluctance to push recalcitrant allies. When the hard-line East Germans last year banned the Soviet magazine Sputnik, Moscow made no public protests. In Czechoslovakia, Gorbachev has permitted a stagnant leadership installed after the 1968 Soviet invasion to hang on to power - to the frustration of reform-minded Czechoslovaks.
``We are testing Gorbachev,'' says playwright Vaclav Havel, a founder of the Charter 77 opposition group. ``We support his restructuring. So why does he keep supporting our old totalitarian structure?'' Pressure for change
Here lies a fundamental contradiction. While Gorbachev aims for stability, his policies of glasnost and perestroika increase pressure for change on his reluctant allies. His stress on noninterference, his denial of the universal application of Soviet experience, his decision to thin out Soviet forces - all these actions undermine the Soviet position in Eastern Europe.
Our leaders ``no longer can claim that Soviet tanks are waiting on the border,'' says Jacek Kuron, a Polish opposition leader. ``Everyone knows that the decision to bring back Solidarity depends on our government - and not on the tanks over the border.''
Soviet leaders are beginning to recognize that stability and reform may be incompatible. Gingerly, they are moving to support reform-minded allies. In his Monitor interview, Bogomolov made it clear that the Czechoslovaks and East Germans should speed up their reform efforts.
``Change is inevitable,'' he said. ``In economics, the role of the market will be heightened. In politics, pluralism must increase.''
``The issue of Soviet troops no longer are a taboo,'' says Peter Molnar, a leader of the independent Hungarian student movement FIDESZ. ``Soon there's going to be a ground-swell call for the withdrawal of all troops - and the communists will have to respond.''
If ``new thinking'' in Soviet foreign policy puts diplomatic pressure on hard-line East European regimes, ``economic restructuring'' means increased commercial pressure on creaky central planning systems.
``We no longer can just go to Moscow and talk to the same person in the ministry,'' says Jochen Harzer of the Textima Kombinat in Karl-Marx-Stadt, East Germany. ``We now have to go out to Novosibirsk or wherever else our customer is and talk to him.''
``The Soviet Union is our largest market,'' adds Karel Dyba, an official at the Institute of World Economics in Prague. ``When we have troubles selling our exports there, it means we have to start reforming our industry and producing higher-quality products.''
Market forces will play a more important role within the Soviet-led trading group, Comecon. Officials at its high-rise headquarters here talk of creating a ``convertible'' ruble which would end the present barter system of trade.
``We want to create a true Common Market within the socialist world,'' says Boris Koltsov, a Soviet delegate to the Comecon Secretariat. ``For this to happen, we know that major reforms must take place in all countries.''
Some skeptics have argued that the acceptance of an anticommunist government in Poland and of a multiparty democracy in Hungary goes far beyond Gorbachev's own plans. The Soviet leader says his aim is to maintain the ``leading role'' of the Communist Party, while the Hungarian Communists plan hold multiparty elections which jeopardize this leading role.
On closer inspection, however, the two positions aren't so far apart. In Moscow, the merits of the multiparty system have become a legitimate subject for scholarly dispute. Soviet officials say that Hungary is a laboratory with lessons that might serve elsewhere. Nothing is off limits in Soviet-East European relations.
``Our Empire is near its end,'' judges Soviet dissident Yuri Metinov. ``After Afghanistan, we have to think seriously about withdrawing all our troops from Eastern Europe.''
``The Warsaw Pact may disappear sooner than we think,'' agrees one East European diplomat. ``Who would have thought the Soviets would withdraw from Afghanistan? And who now thinks they would withdraw from Eastern Europe? With Gorbachev, everything has become possible.''