Buenos Aires — On the day Britain sent its troops back into the Falklands, Jose Blanco, an Argentine engineer, and his wife, Silvia, invited a group of friends over for a barbecue.
As they ate sausages and steaks and listened to music from Argentine folk to American disco, the group - all young, middle-class professionals - discussed restaurants and films.
Only with the coffee did they turn to the subject of the ''Malvinas.''
The low-key reaction of Jose, Sylvia, and their friends to the outbreak of real war in the Falklands was fairly typical of Argentines. The new mood of Argentina toward the conflict with Britain over the Falklands is far less boisterous than in the early days when Argentina swept onto the islands and raised its flag.
The 25th of May - the 172nd anniversary of the May Revolution, Argentina's first major step toward independence - should have been a day of celebration.
But Argentines were subdued that day, their mood tempered perhaps by the morning's communique from the joint chiefs of staff admitting that British troops had consolidated their beachhead near San Carlos Bay. Although it was a national holiday, the junta declared that the only organized public occasion would be a solemn Te Deum in the city's cathedral.
In front of the cathedral in May Square a few hundred portenos gathered, waving flags, clapping, and shouting ''Argentina, Argentina.'' But that was a far smaller crowd than cheered the early moves of Argentina in the Falklands. And it was not as ecstatic as those in previous rallies.
''We're in the hands of our military leaders now. They're not just running the government, they're running our war,'' said a local journalist.
Military leaders, too, now are keeping low profiles. Ever since British troops landed in San Carlos, the junta has refrained from making impassioned public speeches. Official communiques from the chiefs-of-staff began to be delivered in tones that were flat, a far cry from the earlier triumphant reports.
The moderated tone of their public statements may reflect a conscious attempt to prepare the Argentine people for a less glorious outcome to the Falklands crisis, and to minimize the risks of a hostile reaction.
Argentine military officers have tasted real battle for the first time this century. They may not be convinced that they will win the war outright, or at least not convinced that they will get the Falklands without further concessions at the negotiating table. Privately Argentine military officers admit that they will find it difficult to maintain their counteroffensive for much longer without running into serious difficulties in terms of supplies and spare parts.
Military sources believe that the British, with US help, are close to completing an aluminum runway in Port San Carlos and that the Queen Elizabeth 2 cruise liner, carrying 3,000 British troops, will be in the Falklands area by this weekend.
There is a continuing fear in military circles here that Britain might soon attack mainland bases, knocking out aircraft and reducing Argentina's one major advantage over the task force.
Argentine commitment to the war effort, however, should not be underestimated. The counterattack against British task force vessels earlier this week was a boost for Argentine military morale.
The counteroffensive was announced to the Argentine public in a bland style. The attacks on HMS Coventry and the Atlantic Conveyor were confirmed publicly only after they had been admitted by the British Ministry of Defense.
Privately, however, Argentine miltary officers could not hide their delight with what they regarded as their most ''successful'' day since the sinking of HMS Sheffield.
''We have discovered that the British are more vulnerable than we thought at the beginning, when we studied their strength only in books,'' an Air Force officer said.
The military view here is that neither the cover provided by British Sea Harriers nor the British radar and missile system in San Carlos Bay is stopping Argentine pilots from severely damaging the task force.
A significant segment of the Argentine armed forces believes that the Falklands should be held at all costs - even if Buenos Aires has to seek substantial military assistance from outside. The military is convinced that it will have little trouble getting whatever its ask for.
Military leaders are aware that such a move runs the risk of escalating the conflict. But they appear to be preparing public opinion for such an eventuality by allowing the news media to focus on the US military aid being offered to Britain. Argentina is being portrayed as a courageous defender against ''colonialist aggression.''
In spite of a markedly more subdued tone, Argentine rhetoric is still far from giving way to reality. News reports here have successfully insulated most Argentines from the grimmer aspects of war.
''War correspondents'' for the newspapers are mostly military officers who have had a crash course in journalism. Most stories reflect official attitudes or bury battle description in clinical military terminology. TV film gives the impression that soldiers are clean, happy, well-fed, and well rested. Their film clips look like war drills, not real war.