Argentina's top three: precarious perch in the Pink House

The three men who have taken Argentina into war with Britain in the South Atlantic are the latest in a long line of unelected military leaders here.

As the war escalates in cost and in military losses to both sides, both their military ability and political skills are being tested. Pressures on them are mounting.

The trio - Army Lt. Gen. Leopoldo Fortunato Galtieri, Navy Rear Adm. Jorge Issac Anaya, Air Force Brig. Gen. Basilio Lami Dozo - sit in lonely, but powerful splendor in the Casa Rosada (Pink House, the Argentine equivalent of the White House). They are largely isolated from the people they govern, the 28 million Argentines whose destiny is in their hands.

The officers seized power last December, booting out Gen. Roberto Eduardo Viola, who had lost the support of fellow officers and served only eight months of a projected three-year presidency.

The three junta members, led by General Galtieri, remain little known outside the military establishment that bred them. Although there is no group, beside the military, strong enough to challenge the junta, the trio's perch is precarious. Galtieri is the fifth general to govern within a year. The junta's longevity will depend on its conduct of the war with Britain.

Given the limited staying power of earlier military governments and the constant nipping at the heels of the junta by their immediate subordinates in the military, there is no assurance that the present leaders will be in office long.

Galtieri is the junta's leader because the Army plays the preponderant role among the military services and in Argentine society. He uses the title of president.

Galtieri is also said to be the most flashy of the trio. He has, by his own admission to colleagues, found the presidency a difficult, if not impossible position - especially with the pressures that have mounted steadily since Argentina seized the Falkland Islands April 2.

All three junta members are in their 50s - the products of the advanced training in military schools of their separate services. But General Galtieri and Admiral Anaya were boyhood chums. They attended military academy together during their teen-age years.

They took a liking to each other in those years and the young Galtieri, already a big, muscular young man, ''made sure no one beat up on his friend Jorge Anaya,'' as one officer who knows them both put it.

''Galtieri wasn't much of a student, as the more studious Anaya used to help him get through his courses,'' an officer said. Today, they work together in much the same way. But there are some differences.

Galtieri is known for heavy drinking and has a quick temper. He does not like to be crossed. His attention span, when it comes to resolving problems, is said to be short. He wants to make decisions quickly and then go on to other matters.

Admiral Anaya, on the other hand, takes time to think things through. He is the product of the elitist Argentine Navy. Although it has lost considerable influence since the 1960s, when Gen. Juan Carlos Ongania was President and cut the Navy budget sharply, the Navy's traditions remain. Admiral Anaya works to preserve them.

He has been, as one who knows him said, ''gung-ho to get the Navy into action in the war with Britain.'' Never mind that it may be outclassed by the British fleet. He has had to be held in check by his fellow officers.

The admiral is part Bolivian. His father was a Bolivian, and there is talk here that he may have been born in Bolivia, although that is not confirmed. But he was raised in Argentina.

General Lami Dozo's parents were born elsewhere, too. He is Lebanese by ancestry. He bears the image of the fighter pilot, complete with ascot neatly tied at the neck, who won his wings flying jets. He is said to be the most quiet of the three junta members, a man who thoroughly thinks through issues before deciding on a course of action. He does not, friends add, ever lose his temper.

Behind this trio are numerous other military men - most of whom are not known by name to the Argentine public. Lt. Gen. Alfredo Oscar Saint Jean, the interior minister, is the most conspicious. Some say he is the man who would most likely take General Galtieri's place, if he were to step down or be forced out.

Yet General Saint Jean is so closely associated with Galtieri that if the present junta leader were removed, he also might be removed by fellow officers.