Argentina turns to Isabelita to build unity

As she returned here from Spain last week, Maria Estela Martinez de Peron, widow of Argentina's charismatic former President Juan Domingo Peron, personified the mix of comic opera, emotion, and cold calculation that characterize Argentine politics.

She had been invited back by President Raul Alfonsin, who wanted her support as head of the Peronist party to build a national consensus for austerity measures.

Government officials claim that the President believes ''Isabelita,'' as Mrs. Peron is widely known, is the only person capable of controlling the Peronist party. Pressure for a national consensus on economic policy has become intense in recent weeks as the deadline for reaching an agreement with the International Monetary Fund (IMF) closes in.

Mr. Alfonsin won Isabelita's public approval for national unity - at least temporarily. It is not yet clear how far her support will go or to what extent her party will back her.

But it is clear that she is seen as the possible source for a new social pact among government, political parties, and unions. Alfonsin apparently thinks that Isabelita might be able to rally the feuding segments of her party around an effort to bring down Argentina's spiraling inflation - now running at more than 500 percent.

Mr. Alfonsin would also like to get some sort of endorsement for an eventual agreement with the IMF and for Argentina's outspoken stand on the issue of US interest rates, which it claims are strangling the economies of the region. Argentina is negotiating with the IMF for a plan that would refinance more than

Aflonsin decided to woo the Peronists after a drive to reform the Peronist-dominated trade union movement was defeated in Parliament in February.

It remains to be seen whether Isabelita has the political acumen and strength to maintain the loyalties of her party in the days ahead. But she arrived last week - in leather coat, fur scarf, and pungent perfume - flashing smile after smile for thousands of screaming supporters.

There seemed to be no trace of the strain that must have gripped her when, after her husband's death, she ruled Argentina between 1974 and 1976 and plunged the country into political and economic chaos.

She was toppled in a military coup, placed under house arrest, and eventually sent off to exile. With the exception of a brief visit for the inauguration of President Raul Alfonsin last December - she has lived in Madrid since 1981, saying very little.

Before Alfonsin asked her to return home, the Argentine Parliament unanimously exonerated Isabelita from all charges related to her alleged misappropriation of public funds while in office. Justifying this step, Alfonsin has said her return was in the ''national interest.''

Isabelita's return to the center of the political stage stems in part from Alfonsin's invitation, but also comes at the request of the right-wing sector of her party that has always been her base of support.

This group, known as the ''Verticalists,'' says the Peronist movement - an ideologically heterogeneous grouping incorporating different political currents ranging from Mussolini to Marx - should be run along strictly hierarchical lines and that Isabelita is the only ''legitimate'' political heir of General Peron.

They believe that only Isabelita can prevent the party being taken over by the leftists or destroyed by squabbling.

But most local observers believe that a fresh crisis in the Peronist party would be a complicating factor in Argentine politics that could run risks of destabilization.