Buenos Aires — It was the first day of spring. Beneath a clear blue sky, the air in Buenos Aires turned crisp and clean, the schools took a holiday, and the children bought flowers.
The mood spilled over into the next day when, contrary to the gloomy predictions of the skeptics, a massive union demonstration took place without the usual violence.
As he watched the lines of police standing back without drawing their truncheons or throwing tear-gas canisters, Miguel, a young Argentine journalist, smiled and said, ''If this isn't democracy, then what is?''
But not everyone here shares Miguel's seemingly unqualified optimism. Argentina's cautious liberalization is under severe strain.
President Reynaldo Bignone, the head of Argentina's military government, has promised elections will be held by March 1984, but no firm date has been fixed. Labor militancy is growing against the background of galloping inflation and a deepening recession.
''Patience is running out,'' commented a union official.
Last week's mass demonstration - more than 30,000 people turned up in the city's May Square and rallies all over the country drew large crowds - was called by hard-line leaders of Argentina's main trade union organization, the General Confederation of Labor.
Argentine inflation is running at more than 250 percent annually, the highest rate in the world. In a country that has boasted full employment, some 13 percent of the working-age population is now out of a permanent job.
Since taking office in July, President Bignone has gone some way toward meeting worker demands. Wages, family allowances, and pensions have been raised three times, and prices of bread and milk have been controlled. Wage hikes managed to stave off a national strike planned by moderate union leaders of the CGT.
But hard-liners dismissed the increases as not enough. Tension between the government and the unions is expected to increase as Economy Minister Jorge Whebe tries to reschedule part of the $15 million in payments due before the end of this year on Argentina's $37 billion foreign debt.
Some of Argentina's international creditors would like to see Argentina sign a standby agreement with the International Monetary Fund. Even without a formal agreement, some United States and British banks are insisting that Argentina should put its financial house in order and adopt a more monetarist approach to issues like wages.
''The more the government toys with populist solutions, the more chance there's going to be of hyperinflation,'' a local economist says.
The government is also facing pressure from within its own ranks. Formal reunification of the three-man ruling junta around President Bignone last week has done little to appease public criticism and rumblings within the armed forces. The political ambitions of the individual members of the junta are a matter of conjecture, and it is uncertain how long they will endorse Bignone.
Britain and the US would be happy to see the demise of Adm. Jorge Isaac Anaya - the most hard-line and last remaining member of the three-man junta that ordered the invasion of the Falklands April 2. His replacement, Adm. Ruben Oscar Franco, is described by US diplomats as a ''moderate professional.'' But Navy sources insist that Franco will not renounce the Navy's hard-line claims to the Falklands nor its ambitious plans for a major reequipment aimed perhaps at some future presence in the South Atlantic.
The new Air Force chief, Brig. (Gen.) Augusto Jorge Hughes, does not share the presidential dreams of his predecessor, Basilio Ignacio Lami Dozo. But he is known to represent a strong nationalist current within the Air Force, which clashes with President Bignone's more moderate policies. Similar nationalist views are held within the Navy, as was visibly demonstrated last week in an aborted rebellion by a rear admiral.
The Army remains uneasy as the investigation into the Falklands war yields its conclusions a few at time. So far Gen. Cristino Nicolaides, the Army chief, has managed to keep the troops behind General Bignone. But the pressure is growing.
The shock produced by the war has led to a profound questioning of political, social, economic, and diplomatic values that were held sacred for six years of military rule. The nationwide debate has been nowhere more keenly felt than within the armed forces.
Bignone's so-called liberalization has opened up a Pandora's box of vested interests. Rivalries between the services and between individual officers have been eagerly exploited by a news media eager to expose issues that were taboo after the 1976 coup.
In recent days, newspapers have carried reports about senior military officer links with Italy's Propaganda Two (''P-2'') pseudo-Masonic Lodge. There have also been revelations about human-rights violations centered on the assassination in 1977 and 1978 of two senior Argentine diplomats by officers linked to the military regime.