Mitterrand in Moscow. French President's familiarity with Reagan and Gorbachev makes him good go-between

The Soviet Union is hoping that this week's visit by French President Fran,cois Mitterrand will help break the stalemate in United States-Soviet relations. Mr. Mitterrand, French officials again stressed Tuesday, is not carrying a message from President Reagan, whom he met in New York last week. Instead he seems to be trying to act as an interpreter between Washington and Moscow.

The French President's role could best be described as an ``expert,'' or a ``catalyst,'' a French spokeswoman said Tuesday. Mitterrand is trying to explain the US viewpoint on East-West relations to the Soviet leader, the spokeswoman added. He will brief Soviet leader Mikhail Gorbachev on his talks with Mr. Reagan. Reagan has in turn asked to be informed of the outcome of the French-Soviet conversations.

What Mitterrand wants to do, a French official said Tuesday, ``is to give both men the sort of information that, if they decide to change their positions, will enable them to do so in the best possible way.'' The official said that Mitterrand was in an unusually good position to do this: He has a ``forthright'' relationship with Reagan, and also knows Mr. Gorbachev well.

So far, officials say, the talks have gone remarkably well. The two leaders met for longer than expected -- more than five hours in the past two days. And they discussed disarmament and European security ``in a detailed and concrete manner,'' the French spokeswoman told reporters Tuesday.

The Soviets have repeatedly expressed the hope that the present French-Soviet summit would produce tangible results -- a reminder to Washington of Moscow's expectations for any Reagan-Gorbachev meeting.

Asked yesterday what the prospects for a US-Soviet summit were, a Foreign Ministry spokesman repeated that his country wanted to be sure that such a meeting would produce concrete results, adding that Moscow was still waiting for the US to answer its various proposals on arms control.

Before Mitterrand arrived in Moscow, commentaries in the official Soviet news media suggested that the leadership was awaiting the visit with a mixture of hope and apprehension. The Soviets were looking for French help to revive d'etente. But they also seemed nervous that the election in March of a conservative French government might have limited Mitterrand's freedom of action and pushed France closer to the US view of the world.

Although the Soviet government was reassured by many of the opinions expressed by Mitterrand before his arrival here, Moscow was clearly disconcerted by some of the statements of the new French prime minister, Jacques Chirac.

Mitterrand, for example, has expressed his opposition to the militarization of space. Mr. Chirac, on the other hand, has appeared favorably inclined toward French participation in the US Strategic Defense Initiative (popularly known as ``star wars'').

Commentaries in the official Soviet media before Mitterrand's arrival gave almost equal space to Soviet hopes for the visit and Soviet concerns about the recent changes in French domestic politics.

A long article in the government paper Izvestia, for example, noted that the talks between the two leaders assume particular significance because of the ``complex international situation.'' By saying it might not continue to abide by the second Strategic Arms Limitation Treaty (SALT II), Izvestia says, Washington has sparked an arms race.

``The United States, as far as we can judge,'' the article says, ``views the lessening of tension as a threat to its interests.'' Mitterrand-Gorbachev talks, the paper suggested, could improve this situation.

But Izvestia also noted less welcome developments in French politics. Some French political figures, including government officials, had voiced a desire to see France move closer to the US and West Germany, the article said. There had even been talk of France's rejoining NATO. And the majority of the French press, the paper added, was actively and quite successfully fostering anti-Soviet feeling.

The Communist Party newspaper, Pravda, was also ambivalent in its attitude toward the visit. Its analysis of French-Soviet relations commented with concern on the conservative trend in French politics. Then it zeroed in on the French nuclear deterrent. It noted that there was talk in France of increasing its nuclear strength.

``According to press reports, the French nuclear forces are already capable of annihilating hundreds of cities and tens of millions of people,'' Pravda commented. ``Certain circles'' in France, the paper continued, were already openly saying against whom these weapons were directed.

By taking the high ground and seeking to improve communications between the two superpowers, Mitterrand seems to have mollified some of these concerns. The two leaders are to meet at least one more time before Mitterrand leaves for Paris tomorrow.