EAST BLOC IN TURMOIL : NEWS ANALYSIS : Failure of Communism: A New Dimension in Czechoslovakia : East Bloc: Prague’s party leaders seem unable to respond to events. The political momentum is rapidly shifting to the opposition.

PRAGUE, Czechoslovakia--As this nation’s revolution moves from the street to the negotiating table, the extent of communism’s failure here has taken on a new dimension.

At every turn, the Communist Party and those who lead it seem incapable of responding to events.

With each day, its power seems to ebb further as the political momentum accelerates toward the country’s 2 1/2-week-old opposition group, Civic Forum.

An opposition that last weekend was prepared to accept a Cabinet composed of roughly half Communists and half non-Communists, now insists on a minority role for the party and talks seriously of opposition leader and playwright Vaclav Havel as a possible president.

Like the revolution itself, this swing has moved swiftly.

It was barely two weeks ago that the country’s Communist prime minister, Ladislav Adamec, was seen as the key figure for preserving Czechoslovakia’s stability.

Opening the initial contacts with the opposition, then addressing a giant anti-government protest rally in Prague were courageous moves.

As he began to build what he called “a government of national reconciliation” to steer Czechoslovakia to free elections and ensure his own place in history, national spirits visibly rose.

But Adamec proved such a woeful failure that his resignation Thursday was viewed more with relief than dismay. The Communist leader on whom the nation pinned its hopes had offered one government so lopsided with party members that it was stillborn and had simply given up halfway through his second attempt.

“He never understood he was no longer some part of the party Central Committee apparatus,” commented Civic Forum spokesman Jiri Dienstbier.

The party appointed as interim prime minister an unknown named Marian Calfa. With a career mainly as a mid-level apparatchik, he is seen by Western diplomats more as a symbol of the party’s personnel bankruptcy than any indicator of hope.

“Until a few years ago, he was a small-time, back-room lawyer,” commented one dismayed Communist Party member who declined to be quoted by name. “He’s not the answer.”

Commented Havel at a news conference Thursday, “He has been in high government office for at least two years, and in all that time, he has done nothing to attract attention to himself.”

Elsewhere, the party has shown itself weak and uncertain when forced into the glare of publicity.

The new party secretary, Karel Urbanek, has made little impact and seems to have little authority. In his first meeting with Havel on Wednesday, Urbanek reportedly complained that he was incapable of getting district and regional party leaders to understand that the party’s leading role had now gone.

Before his eyes, the Peoples Party that was under the Communist Party’s thumb for four decades has slipped away and effectively joined forces with the opposition in its demands for the new Cabinet.

Both call for 50% of the government to be composed of non-party experts, with the remaining 50% divided among the three existing parties--a formula that would leave the Communists in a minority.

An attempted media offensive launched by the party’s Central Committee to counter Civic Forum’s lively news conferences fell flat, marked by the reading of tedious declarations.

Thursday’s expulsions of former party leader Milos Jakes and Prague party boss Miroslav Stepan carried all the earmarks of a party bracing for scandal.

As the Communist Party sinks deeper into disarray, opposition confidence only grows.

When asked if Czechoslovakia was still a Communist country, Dienstbier told an evening news conference, “Czechoslovakia has never been a Communist country. Czechoslovakia was a country in which the Communist Party implemented its totalitarian power.”

Civic Forum leaders now drive through the capital in new Skoda cars flying red, white and blue Czechoslovak flags.

Thursday, their agenda seemed more like that of rulers than an opposition--calls on the Soviet Embassy, talks at the Prague Defense Ministry and even discussions with a reform group within the Communist Party called the Democratic Forum.

While Civic Forum’s meeting with the Soviets did not include the ambassador, it was interpreted by diplomats as one more turn of the screw by Moscow to force Czechoslovak Communist Party leaders into a compromise to resolve the crisis.

The mood at the opposition’s new headquarters is confident.

“Now everything is possible,” said Dienstbier after learning of the Adamec resignation. “It’s absolutely open.”

Certainly major problems remain.

As weak as the Communists seem to be, the opposition list of seven proposed Cabinet ministers is likely to make negotiations tough. The list includes such names as dissident lawyer Jan Czarnogursky, a man who was on trial for sedition just a few weeks ago.

While the opposition has dropped its Sunday deadline for forming a new government, the pace of events here have left observers believing nothing is any longer impossible.