The Soviet leadership change has set off what amounts to a debate among American experts on how to influence Soviet behavior.
On the one side are experts on the Soviet Union from previous administrations who argue that President Reagan now needs to show less hostility to the Soviets, and indeed should make gestures aimed at fostering Soviet ''good behavior.''
At the very least, some of them say, the Reagan administration should intensify its dialogue with the Soviets, first, so that no misunderstandings will occur, and second, so that if opportunities for change present themselves, the administration will be prepared to act positively. Some Democratic politicians even propose a major peace initiatve on the part of the US.
The administration response is that much of this is already being done. Officials say that Vice-President George Bush and Secretary of State George P. Shultz have carried the strongest possible message of peace from President Reagan to the Soviet leaders who are presiding over the Monday funeral ceremonies for President Leonid I. Brezhnev. Both President Reagan and Mr. Shultz have several times in recent days declared that the US would hope for better relations with the USSR.
In briefings for reporters, administration officials have argued that Reagan's decision to lift natural gas pipeline sanctions against the Soviets this past weekend was part of an allied policy which would make it more difficult over the long run for the Soviets to get new technology and concessionary credits from the West. But the President himself spoke of the sanctions-lifting decision in a way which made it sound like he was extending an olive branch to the Soviets and reinforcing the call for better relations.
Even some of the critics of administration policy think that Reagan's letter of condolence to the Soviet leaders, dated Nov. 11, struck the right tone. It conveyed ''the strong desire of the United States to work for an improved relationship'' and called for ''expanding the areas where our two nations can cooperate to mutual advantage.''
Reagan is also preparing a speech to be delivered shortly which will touch on US-Soviet arms control and possible new ''confidence-building measures'' aimed at averting accidental war between the two superpowers.
But administration experts say that there are limits to how far the administration can, or should, go at this stage. For one thing, they argue that the basic Reagan approach to arms control and other issues affecting the Soviets has been sound and should not be changed. They do not accept the view of some experts outside the administration who argue that the new Soviet leader, Yuri Andropov, will be more flexible than Mr. Brezhnev was.
''It is true that if you read Andropov's speeches, he's a protagonist of detente,'' said one administration official. ''But that means: milk the Western economies, get their technology, and continue to advance as fast as you can in the third world. Use a soft rather than a hard approach in doing this.
''If it's true that we're pursuing a sensible policy, in the US interests, then we ought to go ahead with it. . .,'' the official said. ''We know too little about the dynamics of Kremlin politics to know what would influence the Soviets.''
The official argued that profiles of Mr. Andropov, which have appeared in the Western press depicting him as a ''liberal'' or a ''dove'' in the Soviet context , were the result of ''disinformation'' spread by the Institute of US and Canadian Studies headed by Georgi Arbatov in the USSR.
''They've been portraying Andropov as a cultured, well-traveled, good guy who speaks fluent English,'' the offical said.
Few of the experts, either inside the administration or outside it, see great differences between the views of Andropov and those of Brezhnev. A former ambassador to Moscow, Malcolm Toon, predicts that for the next few years the USSR will see ''Brezhnevism without Brezhnev.'' But the following gives the views of several experts from outside the administration who see possibilities for the US to nudge the Soviets toward change. All of them have had considerable experience in negotiating with, or studying, the Soviets.
* Zbigniew Brzezinski, national security adviser under President Carter, told The New York Times that the Soviets' future course ''depends in large extent on what America does or does not do. . . . Accordingly, the US should try to shape the agenda for the Kremlin by laying on the table constructive proposals regarding the three currently most contentious issues: arms control, Poland, and Afghanistan.''
* William G. Hyland, a deputy national security adviser 1975-76, told National Public Radio: ''I would tilt to concilliation rather than a tough, confrontational position. . . . It could be an opportunity for President Reagan.'' Mr. Hyland recommends intensified private diplomatic probing of Soviet views.
* Malcolm Toon, ambassador to Moscow from 1976-79, told the Monitor he would recommend ''a more intensive dialogue with the Soviets through ambassadors, and at all other levels.'' According to Mr. Toon, ''we should moderate our rhetoric and make sure they do not misunderstand what we are saying . . .I think there is a possibility of reaching arms control agreements, provided there is flexibility on both sides.''
In addition to what these experts are saying, some Democratic politicians are recommending a more open attitude toward the Soviets, including an effort to lower tensions. In a Democratic response to Reagan's radio address Saturday in which he announced the lifting of the pipeline sanctions, Sen. Daniel Patrick Moynihan of New York, proposed that a new American peace initiative be made to the Soviets.
''The simple fact is that we can offer them peace by reducing military costs, '' said Senator Moynihan. ''It's the only way they can restore their economy. The effort of the last two years to say 'we will outspend you and you'll be bankrupt when we are still spending' hasn't worked.''
Ambassador Toon is one of the few Americans who has actually met Andropov. Toon, who saw Andropov at Kremlin receptions, said he doubts that the new Soviet leader speaks fluent English, as some reports would have it.
''If he speaks good English, he kept it well hidden from me,'' said Toon. ''Of course, he and the others knew that I spoke Russian, so perhaps that is the reason that he did not speak English . . . but I don't think anybody in this country has a good fix on Andropov.''