Bonn — East Germany is sticking to its own mini-detente with West Germany - despite some rumblings from Moscow. For the first time in postwar history, the Soviet Union is resorting to thinly veiled public reproaches to one of its two most loyal East European allies (East Germany and Bulgaria). Yet East Berlin is continuing to pursue its own course.
The latest evidence of East Germany's determination to proceed with good relations with West Germany is the institu-tionalization of this policy in the Socialist Unity (communist) Party structure - and the conspicuous promotion of the party official who is responsible for carrying out the policy, Herbert Haber.
The latest evidence of Soviet discomfiture with East-West German coziness is Soviet press revival in the past few weeks of the charge of ''revanchism'' against Bonn. ''Revanchism,'' or ''revenge seeking,'' refers to an alleged West German desire to regain territory lost to Hitler's reich at the end of World War II. This accusation, which has reap-peared in the Soviet news media this month in a degree unknown in the decade of East-West detente, was alluded to only lightly in the May plenum of the East German party Central Committee.
East Germany is now, if anything, reinforcing its own detente with West Germany. Its party-controlled media have been echoing explicit Hungarian claims to national individuality within the Soviet bloc. Significantly, the East Germany party daily, Neues Deutschland, headlined the most important of these comments, ''Common goals, national interests.''
The institutionalization of detente with West Germany was made clear May 25 at the plenum of the party Central Committee. Professor Haber, the official who conducts this policy, leapfrogged directly to the elite 21-member Politburo without going through the customary preparatory stage of candidate (nonvoting) Politburo member. Furthermore, he was named Central Committee secretary; that is , East-West German relations have been elevated to have their own secretary in the Central Committee apparatus.
The promotion of Haber was reinforced by the advancement of two other men to full Politburo status: Werner Jarowinsky and Gunther Kleiber. Both men were part of the ''new guard'' efforts at economic reform in the 1960s. The signal of relative openness to the West given by these three men is unambiguous, especially as it is accompanied by the retirement from the Politburo for reasons of health of the more old-style ideologue and eminence grise, Paul Verner.
Officials in Bonn involved in East-West German relations note that the East Berlin institutional strengthening of detente is taking place despite the ever-worsening superpower relations and Moscow's deliberate inclusion of Bonn in these worsening relations this month during the Moscow visit of West German Foreign Minister Hans-Dietrich Genscher. The officials can recall no similar public sparring over policy between Moscow and East Berlin - as especially manifested in the treatment of ''re-vanchism'' - since the late party and state chief Walter Ulbricht resisted the Soviet turn to detente in the early 1970s.
Officials here regard the present Soviet concern about East-West German relations as somewhat irrational. They think there was good reason for the late Soviet President Yuri Andropov to have approved the relaxation in East-West German relations last summer. In particular, they point out, it procures badly needed hard currency for East Berlin from Bonn and helps give the East Berlin government some badly needed prestige and legitimacy in the eyes of its own citizens. Yet there is absolutely no doubt about the basic East German loyalty to the Soviet Union, West German officials say.
Nonetheless, the current Soviet leadership seems to be giving less weight to the domestic strengthening of veteran East German leader Erich Honecker than to the old Soviet fear of some East-West German deal at the expense of the Russians.
The East German leadership thus has two delicate tasks in its chosen policy. It must perpetuate detente in Central Europe without offending Moscow. And it must give its citizens a sense of increasing contact with the West - without letting expectations get out of hand.
Both of these dilemmas help explain the newest East German clamping down on emigration and peace activism.
Thus, the surprising surge of permissions to emigrate - which brought a 23 -year record of 23,000 East German resettlers to West Germany in the first four months of this year - has ended. Permissions are back down to a rate corresponding to the past decade's average of 9,000 to 12,000 legal emigrants per year.
At the same time, though, the East German police on May 8 ended their ''siege'' of the West German mission in East Berlin - on the day before Moscow withdrew from the Olympics. This followed strenuous objections by Bonn to the intrusive checking and harassment of East German visitors to the mission. That ''siege'' in turn had followed some highly publicized cases in which East Germans who sought refuge in Western missions were allowed to jump the line and emigrate immediately to the West.
The East Germans now apparently believe that they have made it difficult enough for would-be emigrants to discourage the hordes from applying to leave. This permits some letup in the blatant surveillance of Western missions.
The recent East German preventive measures have included the jailing in April of Pastor Wolf Quassdorf after he had visited the West German mission in an effort to emigrate; the arrest of a number of East Germans who have put the letter ''A'' in their windows to advertise their thwarted desire to leave (''ausreisen''); and the reported jailing as well of several dozen peace activists.