Argentine euphoria loses a little of its fizz

A massive rally in Buenos Aires is planned for today by supporters of center-left President Raul Alfonsin to mark Argentina's first 100 days of democratic government.

Posters pasted up around the city call on all citizens to unite for 100 years of ''peace, justice, and freedom.'' It is an ambitious goal in a nation that is less euphoric than it was three months ago.

The change in public mood was visible earlier this month. Only a few faithful supporters gathered outside the presidential palace to wish Alfonsin a happy birthday. Inside, the President was busy at work.

''After years of being ruled by arrogant generals, it's high time we had an essentially humble man committed only to democracy,'' explained one of the President's close aides.

Although local opinion polls still show Alfonsin's personal popularity is high, the democratic government is no longer applauded with the enthusiasm that heralded Alfonsin's inauguration three months ago.

Alfonsin began his presidency with a onslaught on the country's previous military rulers. He court-martialed about a dozen senior officers, including the members of three former juntas, for human rights violations and responsibility for the Falklands debacle. He outlawed torture, lifted censorship, and laid the groundwork for reconciliation with Chile and Britain, reversing Argentina's previous foreign policy.

But in recent weeks these steps have been gradually overshadowed by the country's deepening economic problems. This has threatened to erode the significant inroads that Alfonsin's Radical Party made in working-class areas in the election last October. Economic difficulties also appear to be undermining the support of the middle class, which remains highly consumption-oriented and somewhat fickle politically.

In mid-March the government decreed a seven-day ban on all meat sales. It was the latest in a series of increasingly drastic measures to curb the country's 436 percent inflation.

A complex combination of dwindling supplies, increasing consumer demand, and embezzlement of funds by an intricate chain of middlemen has meant that meat prices have shot up in recent weeks. But for most Argentines the ban on sales - officially called anti-inflationary - was visible proof of the government's inability to come to grips with the economy. Argentines are used to eating steaks. They did not vote in democracy to become vegeterians.

Public annoyance was epitomized by Argentina's most popular cartoon character , a talking duck called Clemente. Midway through the meat ban, the usually fleshy Clemente was reduced to a skeleton.

The government has been similarly unfortunate in resolving the country's $43 billion foreign-debt crisis.

When he took over at the Economy Ministry last December, Bernardo Grinspun was apparently convinced that the restoration of democracy was sufficient to ensure the unconditional good will of the international banking community. But in recent weeks the ''honeymoon period'' has been getting dangerously close to premature divorce. Both sides are hardening their positions.

Mr. Grinspun's refusal to use the country's growing pile of foreign exchange reserves (boosted by grain exports) to reduce interest in arrears on the foreign debt has met stiff international resistance. US banks, in particular, are worried by the prospect of having to classify some $650 million in arrears as nonperforming when they have to draw up their balance sheets for the quarter ending March 31. The danger in such a development is that shareholders and depositors could soon quickly lose confidence, provoking major problems for the banks themselves.

More recently, however, the government has apparently accepted that compromise, rather than confrontation, is in the interest of both sides.

An International Monetary Fund team arrived in Buenos Aires Wednesday to discuss the government's economic goals for the year and its request for further aid. Meanwhile, international lenders were understood to be thrashing out a formula by which they would agree to release around $500 million in fresh credits to help Argentina pay back some of its debts.

Grinspun has reluctantly accepted that some belt-tightening must take place if he is to succeed in reducing the country's huge budget deficit (it was 17 percent of gross domestic product in 1983) to more manageable proportions.

Sharp cuts in defense spending are expected now that the government has defused tension over two key territorial disputes. Argentina has signed a peace treaty with Chile over disputed islands in the Beagle Channel. It has also offered to resume talks on reestablishing diplomatic and trade links with Britain, which ruptured during the war over the Falkland Islands.

Alfonsin's government, however, is still pushing for economic growth of 5 percent this year. It has repeatedly warned that it will not accept recessive formulas as a solution to its debt crisis.

''We cannot survive as the world's Robinson Crusoe by breaking all links with the West. Nor can we accept a tough austerity package imposed by the banks. This will only erode Mr. Alfonsin's popular support and bring in its wake political and social chaos,'' warned Mario Brodershon, president of the state development bank Banade.

Besides economic problems, the armed forces still present a challenge for Alfonsin. Although the military was discredited by the Falklands defeat and revelations of human rights violations, it remains a key factor in national politics. Argentine history has an ominous precedent: No civilian government has ever survived a coup attempt.

With the exception of an unrepresentative lunatic fringe, a wide array of military men have accepted the court-martial of about a dozen senior officers on the condition that punishment will not be extended throughout the armed forces. ''A major witch hunt would detroy our institution,'' a senior officer warned recently.

The government has mapped a relatively moderate position on military rights violations. A new law draws a distinction between the senior military officers who planned the repression and middle-ranking and junior-ranking officers who acted under orders in carrying out repressive acts. Alfonsin's aides admit privately that they see the law as a guarantee that the armed forces will not be completely humiliated in sweeping trials.

In contrast, human rights groups are seeking stiff sentences for more than 100 officers. One of the key questions in the coming months will be whether Alfonsin has the ability to stick to the middle ground between the dogged reluctance of most officers to accept political and moral responsibility for the crimes of the past and the demands for vengeance from their opponents. Each side will continue to pose a potential threat as long as the memory of the ''dirty war'' persists.

Another area of tension is labor. Parliamentary defeat of the government's trade union reform bill this month is a setback for Alfonsin's plans to democratize the structure of Argentina's powerful union movement. The bill proposed a system of direct elections and greater participation of independents on union committees. In the past, union ''bosses'' linked to the opposition Peronist party held a monopoly on union power.

Alfonsin saw the bill as more than a plank in his plans to consolidate democracy. He saw it as an instrument to reinforce his economic policies. Now, however, he is having to rethink his plans. As he does so, leaders of the country's only major trade union organization, the General Confederation of Labor, are charging that the government is too closely tied to the International Monetary Fund.

While Alfonsin appears bent on sending an amended form of the bill for further debate and possible approval, he also favors a more immediate compromise solution. This could involve an agreement with both sides of industry to help implement a more effective prices and incomes policy. In the meantime, however, the government continues to take heart from the divisions of the Peronist party, which failed to recover its political identity after Gen. Juan Peron's death in 1974.