The Curtain Rises: Eastern Europe, 1989 : UNITED STATES : A Once-Wary Bush Is Swept Up in East Bloc Wave of Freedom : The President and his aides now view Gorbachev as a partner in democracy.

For the better part of a year, the upheaval in Eastern Europe has posed two central questions to George Bush and his foreign policy advisers: What do the changes in the Soviet Bloc mean for the West? And how should the United States and its allies respond?

President Bush gleaned a key part of the answer, some aides say, from a most unlikely source: Poland’s dour President Wojciech Jaruzelski, who tried to crush the Solidarity opposition movement in 1981, only to surrender a share of power to it in 1989.

“We are on this path, the path of democratization, for good,” Jaruzelski told Bush last July in a long meeting in the palace of Poland’s 19th-Century kings. Moreover, he added, Moscow had given its full support to reform--with “no limits” on Warsaw’s freedom of action.

Bush, who had gone to Eastern Europe skeptical about the extent of the commitment to reform, was deeply impressed by Jaruzelski’s apparent sincerity--and by his message about Soviet policy.

That afternoon, the President told Poland’s new Parliament: “Because of what you’re doing here, the genuine opportunity exists for all of us to build a Europe which many thought was destroyed forever in the 1940s.”

A few days later, Bush wrote to Soviet President Mikhail S. Gorbachev proposing that the two meet--the invitation that led to the Malta summit.

The changes that have transformed Eastern Europe this year have had a dramatic effect on the Bush Administration’s foreign policy--far beyond the issue of U.S. attitudes toward what used to be called the Soviet “satellites.”

The sudden wave of freedom that has swept through Poland and its neighbors has changed the way Bush and his advisers look at the world. Once wary of Gorbachev, they now embrace the Soviet leader as a partner in diplomacy. Once skeptical of the chances for lasting change, they now proclaim the real possibility of an end to the Cold War.

“As I watched the way in which Mr. Gorbachev has handled the changes in Eastern Europe, it deserves new thinking,” Bush told reporters at a meeting of the North Atlantic Treaty Organization earlier this month. “It absolutely mandates new thinking.”

“The issue had been, ‘Is it going to last or not?’ ” a senior Administration official said. “But with Eastern Europe, you have got some events that, no matter what happens to Gorbachev, are probably irreversible. They can’t be changed. The post-World War II order is gone. The Soviet Union has essentially allowed its bloc, which has been under its tight control, to just go away. And that is a transforming event.”

Eastern Europe is where the Cold War began 40 years ago, with Josef Stalin’s installation of Soviet-controlled governments in the lands occupied by the Red Army at the end of World War II. Ever since, the world’s two most formidable military forces have faced each other across a barbed-wire frontier, with nuclear missiles to back them up. For a long, white-knuckled generation, when strategists in the Pentagon drew up their plans for war, it was Europe they thought of first.

Now, all that has changed. Thanks to the collapse of Communist power under popular pressure in Poland, Hungary, Czechoslovakia and East Germany, the great confrontation that has dominated the second half of the 20th Century appears to be coming to an end.

“The most important development in the world today is the democratization of Eastern Europe,” said Fred C. Ikle, an undersecretary of defense in the Reagan Administration. “. . . If East Germany becomes a democracy, the question of Soviet troops will simply go away.”

The Bush Administration is beginning to agree. “What these changes amount to is nothing less than a peaceful revolution,” Bush said after his summit meeting with Gorbachev off Malta. “The task before us . . . is to consolidate the fruits of this peaceful revolution, and provide the architecture for continued change, to end the division of Europe and Germany, to make Europe whole and free.”

So far, the Administration’s cautious attempts to devise policies to advance those aims have been easily outstripped by events.

Throughout most of the year, diplomats and intelligence analysts expected the Soviet Union to set some limits to the East Bloc nation’s freedom of action. But beyond calling for the maintenance of the Warsaw Pact and opposing any early move toward the reunification of Germany, Gorbachev surprised U.S. officials by setting no other limits.

The biggest surprise of all was the sudden opening of the political system in East Germany, which officials expected to be one of the last Soviet Bloc countries to embrace reform. Bush and his aides were “amazed” when intelligence reports showed that Gorbachev had actively encouraged the overthrow of hard-line leader Erich Honecker, one official said.

The Administration’s response has been characteristically cautious. Bush and his aides have emphasized that they want reforms in Eastern Europe to take place gradually, in a way that will not provoke a backlash from the Soviet Union.

As one surprising result, U.S. diplomats have pleaded privately with leaders of Hungary’s democratic opposition to shelve their demand for withdrawal from the Warsaw Pact, because such a move might threaten the Soviet Union’s sense of security.

“We have no reason to encourage them to leave the Warsaw Pact--it would be unhelpful, so why raise it?” a State Department official said. “Besides, membership in the Warsaw Pact in no way inhibits their reforms.”