Vienna — The reaction in Eastern Europe from Mikhail Gorbachev's Kremlin shake-up last month was mixed. Pro-reformists in Budapest and Warsaw were relieved by the way in which the Soviet leader was able to cut back on conservative influence in the party's top echelon and, hopefully thereby, hasten the pace of the ``restructuring'' process.
In Prague, it was a very different story. At a meeting of the Czechoslovak party's Central Committee Oct. 10 and 11, the prime minister of the past 18 years, Lubomir Strougal, stepped down.
He took office shortly after the start of the antireform ``normalization'' ordered by the Soviets after their intervention in 1968. He was initially a hard-liner but later turned reformist, albeit far from the radical Hungarian pattern.
For leaders who, on the eve of this party meeting, still flatly rejected any reassessment of 1968, even Mr. Strougal's tentative ``restructuring'' carried old risks of ``counterrevolution.'' His replacement was a Czech regional chief, an economist recognized for his ability but not known for any ardor for reforms.
Moreover, newcomers appointed to the foreign and interior ministries, as well as the premiership, are all party lightweights. Inevitably that suggests a downgrading of government and, therefore, a setback for reform.
In East Germany, Bulgaria, and Romania aging leaders still say ``no'' to perestroika (restructuring). The first two are the ``last Mohicans'' of the Brezhnev era, the third harks further back, into neo-Stalinism. They share a preference for an uneasy status quo rather than risk the hazards of reform.
As for Mr. Gorbachev, he does not seem overly bothered by these reform-shy allies. And there has been nothing to suggest pressures on either Hungary, the East bloc's pacemaker in ``revolutionary'' change, or Poland, where outlawed trade union Solidarity's is again a hot issue, to limit the pace or extent of reform.
There now seems to be only one limit in Gorbachev's view. The first pronouncement by his new ideology spokesman, Vadim Medvedev, suggests where the boundary lies: New forms of enterprise management in industry and agriculture are fine. (Indeed, in the Soviet Union the latter already seems tantamount to a start even in dismantling collectivization.) Independent, noncommunist opinion and even election candidates have a right to be heard. And how the East Europeans set about reform is their business.
But changes must not include alternatives seeking to edge the Communist Party aside. The party still has the leading role, even if it is now euphemistically described as only as ``backroom'' guidance.
Gorbachev is said to have a dream: that the East-bloc community Comecon should follow the example of the increasingly integrated Western common market. Events themselves, he apparently believes, will spur the laggards.
Most of the East Europeans face a winter of considerable discontent.
Czechoslovakia and East Germany may give the consumer a better deal. But political alienation is increasingly evident in a dramatic upswing in popularity by the churches and religion, especially among youth.
In Bulgaria, early reform has given way to stagnation under outworn leadership.
Romania, with its severe food shortages, real wage cuts, and a fifth winter of drastic power cuts ahead, had a taste of industrial unrest last year and may well be courting more this winter.
Poland can pump more goods into the market (as promised) but will remain dangerously crisis-prone unless there is a real concession to political freedom.
Even Hungary, with its rapidly expanding openings to the West and ``talk about reform'' briskly translated into action, faces an acutely difficult period.
The ``beginning of the end'' of communism may prove less imminent than Yugoslav Milovan Djilas said it was in a recent interview, with the current unhappy experience of his own country in mind.
The Hungarian way might conceivably turn out better. But for Gorbachev and East European reformers - and still more the anti-reformers - the writing on the wall underscores more that ever before that, without fundamental changes in every aspect of communist rule, the future could well prove Mr. Djilas right.