Buenos Aires — Badly battered by years of internal squabbling and recently by weeks of disastrous war in the South Atlantic, the Argentine Army this week took sole control of the nation.
Although the Army is promising to hold elections for a civilian government by early 1984, its decision to overrule Air Force and Navy wishes on who would lead the government extends uncertainty over the nation's political future.
Selection of retired Maj. Gen. Reynaldo Benito Bignone Tuesday shattered the fragile unity of the services, which have ruled together since the military overthrew the government of Maria Estela Martinez de Peron in 1976. That unity has always been fragile, but it unraveled completely this week as the Air Force and Navy angrily withdrew from the government.
As the nation reeled from this intra-service battle and with General Bignone preparing to assume the presidency July 1, two immediate questions emerge:
* Is he to be a president with power and authority of his own, or will he simply, in effect, be the front man for an Army establishment headed by Lt. Gen. Cristino Nicolaides, the new Army commander in chief?
* Will the new government address itself first and foremost to Argentina's shattered economic structure and begin to rebuild it with viable economic policies, or will it simply put forward old patchwork methods?
There are other major uncertainties - not the least of which is how Argentina will pick up the pieces after its defeat in the Falklands.
There are no ready answers at this moment to any of these questions. Much may depend upon the men chosen as Cabinet members, particularly in the economy, agriculture, and foreign trade posts. Also important will be the new foreign minister.
Names are surfacing like flies in the summertime. Most are not new to government. The list of candidates for posts like economy minister include previous occupants or people who have played prominent roles in the economy. Many are names associated with economic programs in the past that have failed to resolve Argentina's economic traumas.
Among those considered for the key foreign ministry position is Raul Quijano, Argentine ambassador to the Organization of American States. Mr. Quijano served briefly as foreign minister under Mrs. Peron's government in its final days. His selection would lend distinction to the government in the hemisphere. Mr. Quijano is well respected in the United States.
Just as important as who is named to these posts, and what economic course the government runs, is whether General Bignone will be a puppet of the Army or whether he will have authority to act independently.
General Bignone is not well known. Military sources say his career is not one of major distinction.
His appointment ruptured a move toward democratization signaled by the military. Under that process, the president was to be named by at least two of the three services. But Bignone was chosen by the Army alone.
The Air Force and Navy, which apparently had agreed on another candidate, were outvoted - Army General Nicolaides getting his way against the wishes of Air Force Brig. (Gen.) Basilio Ignacio Lami Dozo and Navy Rear Adm. Jorge Isaac Anaya.
''It was a case of one outvoting two,'' said an angry Air Force officer.
Bitterness was evident on all sides. Meetings of General Nicolaides, Brigadier Lami Dozo, and Admiral Anaya have been bruising. They became shouting matches over the weekend with the rhetoric flowing and the invective mounting.
By Monday the generals had become so angry that there was concern among their aides that the meetings might end up in physical blows. It has happened before here.
A determined General Nicolaides, who took over as Army commander in chief June 17, exercised a ''willfulness that we have seldom seen in any military man in this country,'' said one naval observer. ''He weighed into those meetings and called his fellow officers every name in the book.''