Moscow's immediate priority in dealing with West Europe's linchpin, West Germany, is to block deployment there of new NATO nuclear missiles. Once the ongoing Soviet internal power struggle is settled, the Kremlin will be able to focus on this goal. In doing so, it can choose from a spectrum of policies ranging all the way from hints of German reunification to tacit threats to West Berlin.
This is the view of Wolfgang Leonhard, a history professor at Yale University from January to June and one of West Germany's leading commentators on Soviet affairs from July to December. Mr. Leonhard, who was a Communist Party activist in East Germany in the founding years, has in the decades since his defection been analyzing Soviet affairs.
In a telephone interview Mr. Leonhard stressed first of all that Soviet leader Yuri Andropov - ''contrary to widespread opinion'' - is not yet firmly in the saddle. As evidence, he points to the continued prominence in the top Soviet leadership of proteges of the late General Secretary Leonid Brezhnev - and the failure so far to fill two of Mr. Brezhnev's posts: president and chairman of the National War Council.
Pending settlement of the succession struggle, the only foreign policy areas that Mr. Andropov has shown a personal interest in are improved relations with China and somehow getting out of Afghanistan, Leonhard says.
When the new leadership does get around to other foreign policy areas, however, Leonhard says he believes ''the absolute priority'' in dealing both with the US and West Germany will be prevention of the installation of planned new NATO missiles. The Soviets will thus wait for the West German elections on March 6 to see how firmly the new Bonn government will hold to NATO's ''two-track'' negotiate-and-deploy decision.
In the run-up to the German election, the Soviets will continue to fan the antinuclear protest movement in West Germany and opposition to deployment among the out-of-power Social Democrats - as well as show favors to those conservatives who are more pro-detente than their colleagues. By identifying with the peace movement the Soviets hope to gain political influence in West Germany for the first time in the postwar period, Leonhard suggests.
If the March 6 election reinstates conservative Chancellor Helmut Kohl - the incumbent of three months, and a firm advocate of proceeding with deployment - the Kremlin would then have to make further decisions about how to operate.
Already the USSR seems to be toying with shifting the image it presents to West Germany in a somewhat more hawkish direction, an interview with Soviet officials in the Suddeutsche Zeitung suggests. In the period since Ronald Reagan became President, the Kremlin has generally contrasted its own peace-loving nature to alleged American warmongering, in an appeal to the antinuclear movement and antinuclear sentiments within the Social Democratic left wing. In the interview, however, Central Committee member Valery Falin and general staff General-Colonel Nikolai Chervov sound more threatening, in asserting that Moscow will not continue arms-control talks once the first NATO missiles are deployed.
Leonhard does not think that the Kremlin would actually step up pressure on West Germany to overt threats against the East German-surrounded enclave of West Berlin. Its preferred style is to use this potential threat as a known but unplayed card.