MOSCOW, SEPT. 19 -- As the Soviet Union faces one of the most momentous decisions of its 73-year existence, whether or not to proceed with the dismantling of the Communist system, President Mikhail Gorbachev seems either unwilling or unable to give the country a vigorous sense of direction.

In the West, the Soviet leader is often viewed as a bold and visionary statesman whose foreign policy initiatives have changed the world. In the Soviet Union, the father of perestroika and glasnost frequently comes across as hesitant and indecisive, more at home in the world of Communist Party intrigue from which he sprang than the new, more open politics he has done so much to create.

Gorbachev's penchant for political maneuvering has been vividly demonstrated this last week by his ambivalent role in pushing through an emergency economic recovery program. He has made clear his backing for a radical plan to create the foundations for a market economy within 500 days. But he has also expressed political support for Prime Minister Nikolai Ryzhkov, whose government advocates a much more cautious approach.

This week, the president further muddied the political waters by calling for a nationwide referendum on the private ownership of land, a concept that has long been taboo for orthodox Marxists. The referendum idea was dismissed by some of his own advisers as an excuse for postponing painful political decisions.

The legislature of the giant Russian republic, which adopted the so-called "500 Day Plan" earlier this month with only a single dissenting vote, today passed a resolution, 154 to 4, calling for Ryzhkov's resignation. The Soviet national legislature, by contrast, is still bogged down debating the merits of alternative economic programs, and a vote on whether to approve the 500 Day Plan is unlikely before Friday, at the earliest.

Although couched in unideological economic jargon, the 500 Day Plan is effectively a program for the demolition of socialism, as constructed in the Soviet Union over the last seven decades. It envisages the privatization of the trade and service sectors of the economy, the transformation of government-run factories into joint-stock companies and the abolition of state subsidies to money-losing factories and farms.

After arguing earlier this year that a presidential system of government was essential to speed up economic reform, Gorbachev seems curiously reluctant to exploit his new powers. He evidently views his role as the great facilitator rather than the great communicator. Instead of mobilizing public support for his own economic plan, he seems preoccupied with reconciling contradictory points of view and achieving a political consensus.

"Our leader has attempted all these years to preserve a centrist position, steering between left and right. There have been times when such a political course has allowed us to avoid dangerous confrontations. But the end result is that the president is criticized by both sides. The moment of choice has arrived," noted the government newspaper Izvestia this week in a political commentary entitled "The Crisis of Power."

By common consent, the economic crisis now facing the Soviet Union is at least as grave as that experienced by the United States during the Great Depression. The ruble is becoming worthless. The most basic consumer items, such as sugar and cigarettes, have disappeared from stores. Industrial production is dropping. Thousands of factories and farms are kept afloat only by government subsidies.

Viewed through Western eyes, Gorbachev's response to all this has been strikingly unpresidential. He has been unable to tear himself away from the Supreme Soviet, the country's fledgling elective legislature. A special box has been set aside for the president on the floor of the chamber, allowing Gorbachev to intervene in debates whenever he feels like it. There has been little attempt to distinguish between the legislative and executive branches of government.

Some of Gorbachev's own advisers are clearly frustrated by his failure to assume political responsibility for the latest economic recovery plan. Together with Russian President Boris Yeltsin, Gorbachev set up the group that worked out the 500 Day Plan and its proposals for the sweeping denationalization of the state-run economy. But, while endorsing its general outlines, he has stopped short of describing the document as his own program.

"I would have preferred the president to have simply sent the plan to the Supreme Soviet without asking them to debate and approve it. He should have told them, 'This is my plan. If you support me, support this plan.' It would have been a matter of confidence in the president. Unfortunately, I am not sure that our respected deputies understand the serious position that we are in," said Yevgeny Yasin, a leading economist and co-author of the plan.

One possible explanation for Gorbachev's political tactics is that he wants to hold himself in reserve for the next crisis. If he tilts too openly toward the radical-reformists, he could lose his leverage with Communist Party apparatchiks who still exercise considerable power behind the scenes. Such a move also might cost him to his reputation as the indispensable man of the center, a bulwark against extremes.

With hindsight, Gorbachev's ability to fudge and compromise has helped smooth the way for changes that would have been unthinkable just a few years ago. Without his talent for obfuscation and concealment of his long-term goals, the attempt to set the world's first socialist state on a fundamentally new course would probably have fallen apart a long time ago.

When he addressed the Supreme Soviet on Monday, Gorbachev seemed eager to cloak the transition to free-market economic mechanisms in socialist rhetoric. He used Marxist slogans, such as "factories to the workers, land to the peasants" to disguise what is likely to be the biggest sale of state assets ever seen.

The radicals argue that, with the economy approaching a state of free fall, perestroika, or restructuring, is entering a new phase in which political maneuvering must take second place to the adoption of a coherent economic strategy. They credit Gorbachev with shifting power from the Communist Party to the legislature and the new presidential advisory council. Now, they say, the time has come for a clear break with the legacy of the 1917 Bolshevik Revolution.

"Gorbachev's strength lies in his genius for political improvisation. His weakness is that he often seems to have no master plan, no overall strategy," said Mikhail Berger, a respected economics commentator.

The Western image of Gorbachev as a bold and dynamic leader is largely a reflection of his foreign-policy successes. There has been little domestic opposition to his policy of improving relations with the United States and ending the war in Afghanistan. Foreign policy has traditionally been one area in which Soviet leaders have been given a fair amount of leeway by their colleagues in the party hierarchy.

But international issues, however complex, pale beside Gorbachev's domestic problems. What is more, the challenges that confronted the Soviet leader when he came to power in March 1985 seem easy compared to the crisis he faces today. Relaxing press censorship and holding partially free elections required simple political decisions. But building a functioning economy on the ruins of central planning means changing habits and ways of thinking that have taken root over 70 years.

Even if the Soviet legislature endorses the 500 Day Plan before the end of this month -- the program is meant to go into effect on Oct. 1 -- the road ahead is bound to be long and arduous. It is by no means certain that revenues from the sale of state assets will be sufficient to mop up the hundreds of billions of excess rubles now in circulation, a prerequisite for restoring economic stability.

Ryzhkov has predicted that the measures will result in the closing of one-quarter of state collective farms and the forced dismissal of 270,000 coal miners. His chief economic adviser, Leonid Abalkin, has warned of runaway inflation and a catastrophic drop in production. By making clear his opposition to the 500 Day Plan, Ryzhkov seems to be positioning himself to be able to say "I told you so" if the economic situation deteriorates even further.

Over the last year, Ryzhkov has served as a convenient political lightning rod for Gorbachev, taking the blame for the government's failures and errors of judgment. If he is forced to resign, the post of political fall guy will be vacant. Based on his performance during the last two weeks, Gorbachev has no intention of filling that vacancy himself.