Warsaw — This week in Moscow could bring a clearer picture of Soviet policy under the new Kremlin leadership and provide an excellent opportunity for a communist-bloc summit which could well be the most significant one for many years.
The Kremlin will be celebrating on Dec. 21 the 60th anniversary of the formal establishment of Lenin's Soviet state - the Union of Soviet Socialist Republics.
Yuri Andropov, who succeeded to the party leadership a month ago, will be presiding. The first secretaries and heads of most, if not all, of the ruling Communist parties, including the Soviet Union's six East European allies, will be present.
Moreover, both a Yugoslav and Chinese party will be represented at some substantial level. But neither will permit itself to be involved in any multilateral talks or anything that smacks of a bloc flavor.
The occasion will also be important for the West, where very little is yet known of any new trends in Soviet foreign policy, especially in Afghanistan.
The Communist Party newspaper Pravda has just dismissed Western speculation of new Soviet attitudes over Afghanistan. Nonetheless, informed East Europeans, believe that Mr. Andropov may focus somewhat more urgently than did his predecessor, Leonid Brezhnev, on finding a way out of Afghanistan. ''The Russians would like to get out,'' a foreign affairs commentator here said. ''For them it really is a mess - as bad as Stalin's in Finland on the eve of the last war.
''The Pravda article. . . means the new leadership is certainly thinking hard about it. Remember, however, whatever Andropov may decide, he has to have the army with him.''
The general secretary of the Soviet party has the entire apparatus from the Politburo on down under his control, except in a way, the army. At present Mr. Andropov is seen as still having to ''firm up'' his relations with the military, who have a voice of their own that - no matter how cooperative - is still independent of the top party echelons.
Eastern European sources say the West looks too much at Andropov's former post as head of the KGB (security police) and his supposed lack of ''experience'' in the wider political sense.
''The important thing was that his appointment was a deliberate move to bring the KGB under party-political control, one source said. ''In the process he not only showed a sophisticated approach and greatly reduced the (KGB's) sheer terror image, he also gained a broad grasp of what and who really mattered in Soviet society. He also knows Eastern Europe well.''
As for domestic policy, Western observers - but more still East Europeans - noted how in his first speech to the Central Committee as party leader, Andropov concentrated on the problems of the Soviet economy.
Moreover, he dwelt much more on its shortcomings than on areas of progress. He cited many weaknesses that all of the East Europeans - but particularly the Czechoslovakians and Romanians - suffer from as much as the Soviets.
Andropov's four years in Hungary before and after the 1956 uprising are recalled. ''He quickly grasped the essence of the subsequent Hungarian reforms and convinced Khrushchev of the necessity for them,'' said an East German source.
In last month's speech, Mr. Andropov came close to saying outright that the Soviet Union might learn from Hungary's experience in organization and resources. When he suggested that the Kremlin's planning department should leave room for initiative to local authorities in matters of local need, he was, in fact, endorsing something the Hungarians are already doing.
How far anything even on that limited scale can go in the Soviet Union is a question for the future. But East Germans and Hungarians both seem to see straws in the wind that, under Andropov even the Soviet Union might begin to follow Hungarian examples in improving management and initiative.
East German communists see Andropov as ''more professional'' than Brezhnev in his last years. ''To that extent he may be seen as a man of reform. But don't expect 'tiny' Hungary's reform in the USSR. It is too immense and too diverse.''
But a canvas of opinion these last few weeks suggests that many East Europeans feel confident Mr. Andropov will tolerate - and even welcome - prudent Hungarian-style reforms if only as a way of easing economic demands on the Soviet Union itself.
Poland's Gen. Wojciech Jaruzelski has hinted at it as he starts the suspension of martial law. Until a fairly late hour last year, Mr. Brezhnev was ready, for the sake of a ''quiet'' Poland, to tolerate Solidarity. By the same token, his successor is not now going to object to economic reform - here or elsewhere.