The United States moved swiftly to make political capital out of the recent $ 500 million debt package put up to help Argentina reduce its arrears - but the deal may yet turn out to be only a Pyrrhic victory in the complex world of US-Argentine relations.
In Buenos Aires government officials have not been effusive in their thanks. President Raul Alfonsin in a broadcast to the nation last Sunday referred to ''the positive and realistic attitude'' shown by the US government on the debt issue.
But such curt acknowledgement was dwarfed by a speech largely devoted to praise for the regional solidarity shown by Mexico, Brazil, Colombia, and Venezuela (the four Latin American countries that agreed to put up $300 million) and for Argentina's own democracy.
Privately Argentine officials insist the deal vindicated their refusal to be forced into an orthodox settlement of the debt by the imposing deadline of March 31 (when some US banks would have had to classify their loans as ''nonperforming.'') By refusing to pay, they ended up being treated as a ''special case.'' The deal meant they did not have to pay the banks all the interest out of Argentine reserves as had at first been demanded by the banks.
According to the US, the rescue package is not strictly a ''bail out'' since the Treasury will withhold a promised bridging loan of $300 million on the understanding that the Argentines reach an agreement with the International Monetary Fund (IMF).
But again the Argentines have put a different interpretation on things. They claim that although they are prepared to negotiate with the IMF, they are no more committed now than they were before to reaching an agreement. If there is no deal with the IMF within the next three or four weeks, the $300 million lent by the four Latin American countries will simply be converted into advance payment for Argentine exports.
''If the US thinks they have forced us to accept an IMF austerity package, they're wrong. We know that the US Treasury was dragged into this at the last minute because it was scared stiff of what coud happen if the March 31 deadline wasn't met,'' a high-ranking official said last week.
Argentina's attempt to force a more flexible agreement from the IMF and better terms from the banks on the renegotiation of some $20 billion of additional debt payments falling due this year will be in evidence in the US again this week during the separate and ''unofficial'' visits of Economy Minister Bernardo Grin-spun and Foreign Minister Dante Caputo.
While uncertainty over the debt clearly overshadows the current state of Argentine-US relations, there are other issues holding up a more rapid rapprochement between the two countries.
The Argentines have not yet forgiven the United States for what they regarded as ''treachery'' over the Falklands war: ''Anti-Yankee'' feelings were only too visible at demonstrations April 2 marking the second anniversary of the invasion.
The alleged U-turn toward an alliance with Britain against what was widely regarded here as a ''just cause'' was percieved by the civilian opposition - now in government - as a sign of the Reagan administration's basic disregard for human rights.
This attitude also colors Argentine views of US policy in Central America. Buenos Aires sees many of the excesses committed by the former military regime imitated in countries bordering Nicaragua. As a result, Mr. Alfonsin has insisted on withdrawing all Argentine military advisers from the area.
Mr. Caputo's continuing priorities in this area will be to seek reassurances from Washington that no military invasion of Nicaragua is planned.
Washington, however, continues to argue that stability in the region has also to do with Argentine attitudes to nuclear power. These, too, are likely to be on the agenda in this week's talks.
Argentina's radical government is committed to the peaceful use of its highly advanced nuclear program - but it has yet to sign the nuclear Non-Proliferation Treaty or ratify the Treaty of Tlatelolco, which bans the spread of nuclear weapons in Latin America.
Last, but perhaps not least of the agenda items, is expected to be Argentina's continuing claims to the Falklands. Many Argentines still say Mr. Reagan is one of the few men around capable of bringing Britain to the negotiating table.