As the United States and domestic opposition groups hammer at Panama's Gen. Manuel Antonio Noriega, the Reagan administration is more quietly encouraging a democratic transition farther south - in Chile. The task is formidable.
The military regime of Gen. Augusto Pinochet has been in power since a bloody coup in 1973. Now it is trying to perpetuate its rule for eight more years by plebiscite later this year. Despite popular aspirations for democracy, Chile's government appears well entrenched and not yet ready to step aside.
Washington, however, is increasingly convinced that if General Pinochet or his surrogate wins, the result will be a significant popular shift to the far left - and a violent explosion.
``If he runs and wins, there will be polarization,'' one well-informed US official says. And Chile's Communist Party, the largest in the hemisphere outside Cuba, would be the main beneficiary.
US policy toward Chile has changed, a senior US official says. ``Around 1984 to '85, we started taking a different approach to Chile at the same time we were taking a new look at other authoritarian regimes - the Philippines, Korea, Haiti.
``People started to draw new lessons from the fall of the Shah in Iran and of Somoza in Nicaragua,'' he says. The administration began to move away from the so-called ``Kirkpatrick doctrine'' of working closely with pro-Western dictators.
``We have come to see that the best defense against any form of extremism is the establishment of strong democratic institutions,'' the senior official explains.
The change has been evolutionary and involved to-ing and fro-ing within the administration, similar to that surrounding policy shifts on Panama and the Philippines. The bottom line, however, has been more and more explicit support for a rapid move to democracy and restoration of human rights.
In December, President Reagan endorsed an unusual official statement supporting a return to ``full democracy.'' The US declaration says ``a climate of freedom and fair competition must be established many months before'' any vote and calls for a series of specific moves, including an end to government use of a state of emergency to suspend democratic rights, free access to the media, and unrestricted political debate.
Washington added bite to the declaration by separately ending preferential treatment for Chilean exports to the US. Since January, the US has also dropped its longstanding objections to the United Nations' treatment of Chile's human rights violations as a special case. Washington is keeping up bilateral pressure on outstanding human rights cases, such as the unsolved 1975 car bomb murder in Washington of a former Chilean minister, which the US believes was planned by senior Chilean officials being sheltered by the Pinochet regime.
US concern has increased with the approach of the plebiscite, expected between September and December, and mounting evidence that Pinochet wants to be the regime's candidate.
Under Chile's Constitution, voters will be allowed only to vote yes or no for the regime's candidate. If the person is not elected, the law calls for a multi-candidate election to be held within a year.
Pinochet has been on an unannounced campaign trail for about six months, US officials say. He is appealing on the basis of his regime's record. He is also relying on substantial porkbarreling, while preventing the opposition free access to the media and continuing overt and covert intimidation of critics.
Just this month, despite Mr. Reagan's appeal, Pinochet renewed both the states of emergency and of danger for three months, which gives him free rein to control critics. Two days after the 14 democratic opposition parties announced formation last month of a coalition to vote ``no'' in the plebiscite, the coalition leader was arrested for an interview he gave a year ago.
More ominously, the covert right-wing terrorist group ACHA, or Hatchet, continues to threaten, kidnap, and kill regime opponents. US officials say this group is part of the ``armory'' that Pinochet's supporters use to intimidate. Intelligence reaching Washington leaves little doubt, sources here say, that Chilean officials are deeply involved in torture and killings of violent and nonviolent opponents.
Chile, however, is a much tougher nut to crack than Haiti, the Philippines, or Panama, US officials say. Its military regime is more cohesive and institutionally stronger than in those other countries. US economic and political leverage is less. The US has no bilateral aid program, has little contact with the military, and has nothing like the economic ties with Panama.
The noncommunist opposition in Chile has been weak and divided. Unlike the Philippines, no leader has emerged for the population to rally around. Outbursts of popular unrest, such as those that led Jean Claude Duvalier to flee Haiti, have been quickly put down. Pinochet also retains international ties: US efforts to halt loans to Chile from international development institutions have been opposed by such US allies as Britain.
The administration has thus decided to walk a careful path of symbolic statements, combined with concrete actions aimed at promoting a transition. Officials have spent a good deal of effort working with Congress. One clear sign of this was quiet cooperation last year in appropriating $1 million for the National Endowment for Democracy to use in supporting democratic opposition parties in Chile.
The Pinochet regime still has its vocal supporters, such as Sen. Jesse Helms (R) of North Carolina. Others want the administration to take more forceful action. Some advocate applying trade sanctions, which the administration opposes.
But there is bipartisan congressional support for current policy, which stands in sharp contrast to polemics over Central America.
Despite the limits, however, the US does have an impact on Chile, officials say. One sign is pamphlets, circulated by the Chilean government in Santiago's subways, accusing Washington, Havana, and Moscow of trying to topple the regime. Pinochet is also sharply critical of US policy, in public and private.
``He feels betrayed, because he thought he would get along well with the administration, but he's finding that we are being even tougher than our predecessors,'' a US policymaker says.
US officials believe senior members of Pinochet's regime and many of his prominent supporters see the dangers of continued dictatorship. Washington has carefully stressed that the military has its place in Chile and that there are a variety of ways to make the transition to democracy, but its private warnings about what the future may provide are also clear.
Pinochet and the Chilean Communists have a ``symbiotic'' relationship, according to US officials. ``They need Pinochet and he needs them,'' one specialist says. Pinochet justifies his harsh measures and continued rule by the growing Communist threat, and the Communists attract new supporters for violent opposition because of his repression.
Indeed, Cuba's Fidel Castro privately tells noncommunist leaders of his weapons support for Chile's communists, US officials report, because he believes the aid is respectable in Latin America. The Communist Party is believed to have regained its pre-Pinochet standing of about 15 percent of the electorate.
While this poses a legitimate security concern, US officials say a Pinochet victory this year will only drive more Chileans into violent opposition. ``This would not only affect Chile,'' a key official says, ``but there would be significant spillover into Peru and Argentina,'' which would likely serve as transit points for Cuban arms.
Officials underline that the US cannot impose democracy on Chileans. If Pinochet or his chosen candidate wins a fair election, Washington will accept the results. But current soundings show Pinochet winning a maximum of 20 to 30 percent of the vote. If he tries a clearly rigged election, officials say, Chile will be very hard to rule and the US will have no choice but to be ``much tougher.''
Thus they hope the government will abide by the constitution and hold multi-candidate elections or negotiate a clear transition to democracy.