NEWS ANALYSIS : Revival Hopes for Soviet Union Dim : Breakup: Readiness of U.S. and allies to accept Ukrainian independence, fostered by Gorbachev’s failure to forge unity, underscores sense of inevitability.

The readiness of the United States and its European allies to recognize Ukrainian independence brings to a halt any meaningful effort to reconstitute the Soviet Union as a single state, ending an era that shaped much of the 20th Century but providing no clear vision for the future.

In deciding Tuesday to accept the inevitability of the Soviet Union’s breakup, the Bush Administration looked forward not only to the results of this Sunday’s independence referendum in the Ukraine but also at the failed efforts of Soviet President Mikhail S. Gorbachev this week to preserve his country’s unity in some form.

The decision, resolving months of debate in Washington and other Western capitals, is certain to prove fateful, accelerating the geopolitical changes that began with the collapse of socialism in Europe.

Some casualties are already clear:

* The Soviet Union as a superpower partner for the United States, a major element in the “new world order” projected both by Gorbachev and President Bush, is gone. In its place will be Russia, reemergent as a classical European “great power” but uncertain how to define that role today.

* Gorbachev is now truly a president without a country. He had staked everything on being able to hold together the remnants of the Soviet Union, and in failing at that, he has failed in everything. A European ambassador Thursday called him, “yesterday’s man--someone to be thanked and bade farewell.”

* The 60 million people of Soviet Central Asia, among that country’s poorest, are likely to be cast adrift amid increased turmoil. Without the Ukraine to help share the burden, the Russian Federation will find little profit in empire; indeed, the predominantly Muslim region is already viewed as a political as well as economic liability.

* Bitter ethnic rivalries, which had been held in check by the Soviet system of centralized state power and its socialist ideology, will now proliferate. Already, there are half a dozen continuing armed conflicts in the Soviet Union, and Russian nationalism is stirring in reaction to the Soviet breakup.

These changes, and more, stem from a rigorous political logic:

Anticipating an overwhelming “yes” vote in the Ukraine, the United States signaled its recognition of the Ukraine as an independent state--and thus guaranteed the result by assuring Ukrainian nationalists of the republic’s international acceptance.

Without the Ukraine, Gorbachev’s faltering efforts to restructure the Soviet Union as a “confederative state” will collapse, as Russia, finding itself partnered with the five Central Asian republics, declares the confederation must be founded on its terms--or not at all.

Russian President Boris N. Yeltsin had already insisted Monday on a much looser structure to ensure Russia’s political control of the new union and to prevent its wealth from being siphoned through a central government into Central Asia. Russia is by far the largest of the Soviet republics.

The president of the republic of Uzbekistan, Islam A. Karimov, reacted by suggesting that the whole effort be reconsidered; his republic, he said, would “not again become a Russian province.”

Whether or not Yeltsin’s demand for control of the confederation is accepted, Russia is already going its own way, further justifying the Ukraine’s fears that it would forever be the “younger brother” in any new Union Treaty.

But Yeltsin, convinced that Russia will flourish once it is freed from the Soviet system and its socialist orientation, is strengthening day by day his “Russia first” approach and forcing changes by using Russian “sovereignty” to make over a centrally planned, state-owned economy into one based on market forces and entrepreneurship.

Leonid M. Kravchuk, chairman of the Ukrainian Parliament and the front-runner in Sunday’s presidential election in the Ukraine, said this week that he doubts a confederation could be formed with one member so dominant.

“I believe in a treaty with Russia more than a Union one,” he said, suggesting it would easier to live with Russia as a foreign country.

The U.S. decision seems certain to harden the resolve not only of the Ukraine but several other Soviet republics to pursue their own advantage wherever they find it, whether in full independence, in confederation with Russia, in an economic community that preserves the present Soviet market or in alliance with neighboring countries--Moldova with Romania, for instance, or Azerbaijan with Iran.

“The independence referendum was a challenge to our entire policy on the Soviet Union and the way we have viewed this country since World War II,” a senior U.S. government specialist on relations with Moscow commented, asking not to be identified because of his policy position in Washington.

“The Ukraine has been part of Russian power and of Soviet power for hundreds of years, and we have been used to dealing with it as such. And so we are now talking about the breakup of the Soviet Union. . . .

“Before, our policy was promoting democracy and free-market relations on the entire territory of the Soviet Union with the assumption it would hold together,” he continued. “In the final analysis, our policy goals were contradictory.”

The change in U.S. policy undoubtedly hit Gorbachev hard, for Bush had, until last month, worked to underpin his leadership and preserve the Soviet Union as an integrated state.

Even as negotiations fell apart this week on a new Union Treaty, Gorbachev was hopeful that the Ukraine would join the effort to establish the new “Union of Sovereign States.”

But the U.S. decision, reflecting a growing consensus in the West, implies that in the world’s judgment Gorbachev is no longer the instrument of progress but an impediment blocking resolution of the Soviet crisis by trying to maintain an artificial union.

Washington, moreover, apparently sees no value in maintaining Moscow as a nominal, even fictional partner in such endeavors as the Middle East peace conference.

“This must have been a crushing blow for Gorbachev,” a senior European ambassador said. “He was all that was holding the Soviet Union together, at least in international terms, and his efforts are now rejected by Bush as a failure.”

Yet, the gains from the U.S. policy shift are far from certain, both for the former Soviet republics and for the United States and its allies in Europe and Asia. They depend heavily on everything going right, on managing fast-paced changes at lower, less experienced levels of political leadership, on not compounding problems by dragging out their solutions and on “best case” rather than “worst case” scenarios.

But, in recognizing Ukrainian independence, the West faces immediate problems, which only grow with the dissolution of the whole Soviet Union.

With its plans for armed forces of 420,000 and its inheritance of 176 nuclear-armed, intercontinental nuclear missiles, the Ukraine almost instantly becomes a major player in the balance of power in Europe. It will have more nuclear weapons than Britain, France and China combined, more troops than Germany.

While U.S. officials express confidence that the Ukraine will quickly accede to disarmament treaties, the mood among Ukrainian nationalists is to retain these trappings of statehood, as potent as they are emblematic. Kravchuk suggested, for example, that it would be difficult for the Ukraine to give up its nuclear missiles so long as Russia retains its arsenal.

Although some free-market economists in the United States have argued that integrating Soviet republics into the world economy will be easier on an individual basis, the collapse of the Soviet economy is imminent, and all the salvage plans up to now have been based on preserving it as a whole, not on dealing first with Russia or the Ukraine.

“Question: Will it be easier for us and the world to resolve the problems of a dozen different countries, some big, some small, some European, some Asian, some nuclear powers, others not, (some) rich . . . and others very poor?” asked a Soviet political scientist who advises Gorbachev. “I think not.

“We pursued an integrated answer in the belief that it was easier to develop variations on a central theme. We no longer have that option. Perhaps it was an illusion, and our efforts had been overtaken by events in the Ukraine. But we have added new problems to the agenda without resolving the old ones.”