There was no honeymoon for Alan Greenspan when he took over three months ago from Paul A. Volcker as chairman of the Federal Reserve. Financial markets and Treasury Secretary James A. Baker III saw to that.

Instead, Greenspan has faced a tumultuous, risk-filled 100 days that included sharp declines in the value of the dollar, periods of swiftly rising interest rates and the biggest stock market plunge in history. Along the way, Baker dumped an untenable international agreement to try to keep the dollar from falling below certain levels, and in the process left the clear impression that he was giving the Federal Reserve monetary policy marching orders.

The Baker statements worried many financial analysts who feared that the treasury secretary's new emphasis on keeping the U.S. economy out of recession by holding down interest rates -- even if it meant a falling dollar -- could lead to an inflationary monetary policy. The comments, in a Wall Street Journal interview, raised questions about what Greenspan and other Fed policymakers would do if market forces were pushing up interest rates, or if they felt for some reason that they should boost rates.

For the moment, the risks of a worldwide financial panic seem to have receded as the weeks pass without any sign that the stock market debacle is being followed by a cumulative decline in financial markets or by a slump in real economic activity in any major industrial country.

However, Fed policymakers around the country are continuing the unusually close surveillance of all parts of the economy begun a month ago. Fed officials at the system's 12 regional banks are amazed at how little damage they can turn up.

At the Atlanta Federal Reserve Bank, president Robert Forrestal says, "I have had extensive conversations throughout the South, and it has had no noticeable effect on business. Businessmen are not changing their plans and orders are strong. Some industries are going flat out. Bankers tell me the same thing.

"Consumers also have not changed, despite what the {consumer confidence} surveys say," Forrestal adds. "I find it hard to believe that with that loss of wealth {from lower stock prices} that we won't have some pullback, but we haven't found it yet."

But Greenspan and other Fed officials undoubtedly are keeping their fingers crossed. If the dollar should go into a nose dive and long-term interest rates shoot upward again -- as occurred just before the stock market plunge -- the central bank could find itself facing a new crisis. Under such circumstances, the Fed might have no choice but to tighten policy to protect the long-term integrity of the financial system even if it means a recession for the U.S. economy.

Certainly there are no signs of a recession right now, though a number of economists, such as Roger Brinner of Data Resources Inc., are predicting a period of very slow growth for the first half of 1988. And Fed officials say they have every reason to try to avoid one.

"Yes, there is something unique in my mind about the need to avoid a recession now," says Roger Guffey, president of the Kansas City Federal Reserve Bank. "Today we are so interconnected with other industrial nations that if the United States were to go into recession, the impact on other nations would be dramatic. We would have a recession around the world.

"What happens if you have a worldwide recession?" Guffey asks. "Is it easily corrected with fiscal and monetary policy actions? Remember, we are dependent on increasing our export markets to reduce our trade deficit. This is a change of circumstance ... a unique period. We have to buy some time to let the needed adjustments take place," Guffey says.

In the sometimes subtle world of monetary policy and financial market confidence, buying time can be a matter of showing firmness in monetary policy. At the end of August, only three weeks after Greenspan arrived, the dollar was coming under downward pressure on foreign exchange markets and long-term U.S. government bond yields were beginning a surge that would take them to nearly 10 1/2 percent before the Oct. 19 stock market plunge.

"A lot of people were worried about a resurgence of inflation, even if the data did not show it," explains Fed Governor H. Robert Heller. "I think we had to act to prevent that from becoming a general reality. These expectations, they can become reality very quickly."

On Sept. 4, Greenspan and three other members of the Federal Reserve Board voted to raise the Fed's discount rate -- the interest rate it charges on loans to financial institutions -- from 5 1/2 percent to 6 percent. There was also an accompanying decision to make cash a little less readily available to the banking system, a step that also nudged up short-term interest rates.

Heller, who later said he supported the increase, and Governor Martha Seger were not present. The seventh seat on the board is vacant. The board sets the discount rate, while the Federal Open Market Committee, whose participants include both the board and the regional bank presidents, decides how much money to provide the banking system.

Not all Fed policymakers were sure the discount rate needed to be raised because of anything happening in the markets. However, they still felt it was a wise step since it did demonstrate to a skeptical marketplace that a Greenspan-led central bank was willing to raise rates to counter inflationary pressures.

The new chairman was heading for Basel, Switzerland, that weekend for his first meeting with foreign central bank officials at the Bank for International Settlements. The BIS is a sort of bank for central banks, and periodic meetings there provide a chance for officials to exchange views on a regular basis. With a discount rate increase announced, Greenspan's standing was probably enhanced.

Of course, that was only the beginning. The dollar continued to be under pressure and many market participants expected that its defense would mean another discount rate hike shortly. In mid-October, long-term rates began to soar and the stock market collapsed.

At that point, all the signs got reversed. Instead of inflation, the market foresaw recession. And instead of countering inflation fears by tightening policy, Greenspan announced that the Fed would provide whatever money the banking system needed. So far the tactic has worked well, in the view of most financial analysts.

Greenspan's momentous three months can be compared and contrasted with those Volcker experienced in the summer and early fall of 1979. Volcker, too, was immediately confronted with major financial problems, including a very weak dollar, when he assumed the chairmanship.

Then the challenge was to find a way to beat down a high and rising inflation in an economy suffering from the second of the decade's oil price shocks. Neither the federal budget nor the nation's international trade was as deeply in the red as today, but with the inflation and a lack of confidence in the Carter administration, the United States was having a hard time finding foreign investors willing to finance its international deficit.

Within two months, Volcker had persuaded other Fed officials that monetary policy had to become much more restrictive to fight the inflation, and the central bank's whole approach to day-to-day implementation of policy was changed to further that end.

In some ways, Greenspan has had to cope with even more urgent problems, including the possibility of a worldwide financial panic. "Paul, in a sense, inherited a situation he was able to move and address," recalls Guffey. "Alan inherited a situation but had no time to address it."

Given the speed at which events have moved, Greenspan has paid a price for not being Volcker. Despite Greenspan's long support for strong anti-inflation policies, both as chairman of the Council of Economic Advisers in the Ford administration and as a prominent private consulting economist, financial market participants could not be sure how he would perform in his new job.

Volcker, on the other hand, had after eight years as chairman achieved demigod status in the eyes of many market participants. They certainly had long since stopped questioning his willingness to act independently. Treasury Secretary Baker's comments about holding down interest rates reminded people they had yet to see Greenspan assert himself.

In fact, there is no evidence that Baker has sought to dictate policy, though he and Greenspan are in frequent communication. It seems clear that Baker now regards the September discount rate increase as a mistake, though as Heller notes, "At the time I did not hear any administration officials arguing against it." Heller, Forrestal and a number of other Fed officials say that decision was correct under the circumstances.

Interestingly, what happened in August and September is not unlike what took place in April, when Volcker was still chairman. The dollar began to fall and market-determined interest rates began to rise. The Fed responded by tightening credit conditions, but there was no increase in the discount rate.

"The run-up in rates was greater in August and September, but essentially it was the same situation," says Atlanta's Forrestal. "It was more intense in August."

Since the stock market collapse, there has been little disagreement over policy since the Fed has sought to keep rates low by pumping plenty of cash into the banking system -- just what Baker sought.

Ironically, some of the same financial analysts who worry most about the Fed's independence and fear the Treasury could be too intent on keeping the economy growing through the 1988 election and the end of President Reagan's term -- whatever the longer-term inflationary consequences -- give Greenspan high marks for precisely that policy response to the crisis.

But market fears can be persistent. The issue is not current policy but what will happen in the future. Last week Greenspan felt it was necessary to provide explicit assurances that the administration had not taken control of the nation's monetary policy.

"We try to coordinate with them in so far as we are both a part of the United States government ... but the presumption that the Treasury controls monetary policy is false," Greenspan declared at a congressional hearing. "I know of no Federal Reserve policy actions which are affected by the Treasury Department."

That Greenspan made such a statement underscored his concern about how Baker's comments had been received by the markets. He has made few public comments about monetary policy since August.

Other Fed officials, who think he has been wise to let policy actions rather than statements calm the markets, were pleased at last week's pointed comments. "I'm glad he said what he did," says Robert Black, president of the Richmond Federal Reserve Bank. "It was time to lay those rumors to rest."

Greenspan's testing period is hardly over. The markets will remain skeptical and financial uncertainties abound. The federal budget deficit remains large and the United States remains dependent upon an inflow of foreign capital of about $160 billion a year to finance its international transactions deficit.

The latter leaves the country vulnerable to changes in sentiment abroad. For instance, a sharp drop in the value of the dollar could persuade foreigners that at current interest rates investing in the United States is not worth it, given the exchange rate risk they would also face. Fed officials would find it hardest to deal with that combination.

On the other hand, not all the news of the past three months has been bad. The real economy still appears healthy and the latest figures for producer prices and consumer prices have shown moderate rates of increase. And the stock market plunge itself has had something of a silver lining.

"A very important thing has happened," says Heller. "Inflationary expectations, the thing we set out to fight in September, have been reduced." That is evident in the lower level of long-term interest rates, he said. "You have a different world out there. What is appropriate policy after the crash was not appropriate before it" in terms of the level of short-term interest rates, Heller added. "The crash reduced inflationary expectations {to an extent that} may have taken half a year or more to accomplish with policy."

Meanwhile, a number of other Fed officials, including Vice Chairman Manual Johnson and Governor Wayne D. Angell, have sought to assure market participants that the Fed will reduce the flow of money to the banking system promptly if new signs of inflation, or rising inflationary expectations, emerge.

And in the background, the shadow of the so-called Louvre agreement is no longer hanging over the central bank. That agreement between the United States, Japan, West Germany, Britain, France, Italy and Canada, signed last February, called for economic policy coordination among the nations and for action to stabilize the value of the dollar relative to other key currencies.

Whatever its merits at the time, the commitment to defend the dollar's value at a given level in comparison with other major currencies for an extended period of time proved unworkable. When the dollar fell, the market routinely expected the Fed to boost interest rates to attract more foreign investment to the United States, a process that increased the demand for dollars and supported its value.

When push came to shove, Baker, who had helped negotiate the deal, decided that holding interest rates down was more important than keeping the dollar up. Some Fed officials were happy with his choice since it gives them more freedom in choosing a course for monetary policy.

Whatever does happen in coming months, Greenspan has tried to make sure he will have a united Fed behind him. He has made a considerable effort to involve the Fed staff, other board members and the reserve bank presidents in the policy process to a greater extent that was true under Volcker. They are singing his praises.

"I think it has been great," says Heller. "He has been open and communicative. He has relied on the board and the rest of the FOMC for input, for any suggestions.

"Now he has been tested by fire. In the first month, they said he has not been tested yet. When he was, he responded and everybody has praise for that ... There hasn't been really anybody outside that said we made mistakes" since stock prices dropped, Heller said.

Guffey and Black echoed the sentiment. "Greenspan has demonstrated an understanding of the institution, the strengths and the barriers in it. ... To me, he has shown a quick read of the Federal Reserve and what makes it strong," said Guffey.

"He just knows what to do," added a pleased Black. "It's like he had been training for it all his life.