Argentina's military rulers and its veteran civilian leaders are caught up in a strange political dialogue, at once anarchic and predictable, and as familiar here as a mournful old tango.

This time, it began with the "covenant." Earlier this month, the governing military junta called out the country's labor and political leaders and sternly issued a 15-point program for negotiating a military withdrawal from power.

The offer had long been anticipated. But the military was shocked by the response: a quick and clamorous jeer. Argentina's politicians collectively announced that they will have no part of the military's program and began organizing mass demonstrations to seek an immediate date for elections.

The result has been a public impasse, and to many political observers here, it means national politics have taken a foreseeable course. Argentina, they say, is back on the "see-saw," or pattern of flips between military and civilian rule.

"When a military government announces it is leaving, it gets a little more destabilized with each day that passes," said a veteran political operative here who has worked with both military and civilian leaders. "The political parties rise with each slip of the military. The result is that there is never a balance, and you never have an agreement. What you have is constant instability."

Argentina has shifted seven times between military and civilian rulers in less than 20 years. Increasingly, the civilian governments have seemed doomed to survive only as long as it took a temporarily shattered military to reorder its ranks and regain some prestige.

Now, with the country attempting another transition to a democratic government, many analysts express concern about whether they will finish with yet another weak civilian government or if the country's growing turmoil will simply propel the old see-saw of generals and politicians into something much worse.

Argentine analysts worry that neither the military nor the jaded political leadership--with its public intransigence and occasional secret bargaining--will have the ability to control the planned move to democracy by March 1984.

Even as the military and parties have quibbled, strange, little-known groups have begun to appear with agendas of violence and what Argentines call "black propaganda," unsettling both the government and its strongest opponents.

In recent weeks, supposed military groups such as the "White Sabers" or "33 Easterners" have made themselves known to promote esoteric nationalism or other antidemocratic causes. Journalists and politicians have been threatened, followed and sometimes attacked. A "clandestine junta" has mailed out cassette tapes and interrupted radio broadcasts with messages demanding the cancellation of elections and a new dictatorship.

Meanwhile, the newly legalized political parties are finding that their reaffiliation drives are gaining surprisingly little support, even as mass movements have begun to form outside of the parties' leadership.

Last week, both military and political leaders were disturbed by a series of demonstrations that erupted in Buenos Aires suburbs over taxes, including one rally that resulted in street fighting between police and angry local residents.

At the same time, the conspicuous silence of all but a few politicians about the 6,000 to 15,000 Argentines who disappeared during the military's violent campaign against terrorists and internal opponents has been outflanked by a swelling movement that has made human rights Argentina's principal public issue.

While most politicians here still discount the possibility of a successful hard-line military coup, the growing disorder has begun to be compared to that of the early 1970s, when a series of movements on both the right and left plunged Argentina into years of constant political violence and finally helped provoke the military's 1976 takeover.

And at the root of the problem, these analysts say, is the Argentine see-saw, and the peculiar, almost ironic political concept of a "covenant."

The present military government of retired Gen. Reynaldo Bignone, installed July 1 after Argentina's defeat by Britain in the Falkland Islands conflict, is not the first to propose a kind of national pact to solve the country's problems. For decades, Argentine leaders have been preoccupied with the idea of universal national agreements, and the "covenant" is a key part of the ideology of the nation's largest political party, the Peronists.

Only months ago, before and during the Falklands conflict, a host of political leaders was clamoring for the military to agree to a "covenant" or a "national reconciliation" that would heal the nation's differences and prevent another cycle of tumultuous transition, weak civilian government and military takeover.

But, it seems, a "covenant" was never really the goal of either side. Even while Bignone's government was being formed, military leaders rejected the idea of negotiations with civilians. Then, party activists say, the armed forces set off the see-saw with two tactical mistakes.

"First, the junta announced that it would institutionalize the country by March of 1984; it set a fixed period, without getting anything in return," a politician here explained. "Then, Bignone lifted the restrictions on political parties. And so now, the parties have nothing to bargain over but a date of elections -- the military just doesn't have any cards."

Inexorably, the balance swung from one political side to the other. This month, the military found itself wanting the negotiations it had turned aside before. A long list of topics was proposed, including the Falklands war, the missing people, the foreign debt and the appointment of future armed services commanders in chief.

Within 10 days, every major Argentine political leader and labor union had rejected the package. "If the government wants to talk about a date for elections we will see," said Deolindo Bittel, a leader of the Peronist Party, who had once advocated broad talks. But, he added, "What use have discussions with the government been so far?"

Negotiations are not entirely off. While publicly rejecting all compromise with Bignone's weak government, some prominent politicians have been slipping through the back doors of the military barracks to quietly horse-trade on sensitive issues.

Meanwhile, both government and party leaders say they face an uphill task in convincing a majority of Argentines that all they are doing has any real significance.

"We have a people that are totally apathetic and cynical," said Jorge Daniel Paladino, a Peronist Party leader. "They don't believe in anything or anybody anymore. Maybe if we start to act with some seriousness and maturity, we can gain their support. But right now we don't have anything."