But what should the CIA be doing?

THE fuss over whether House Speaker Jim Wright should have talked about Central Intelligence Agency activities in Nicaragua has obscured the more important question of what the CIA should be doing in Nicaragua, if anything. Despite the Speaker's disclosures, we do not really know what the CIA is up to. But we know something of what it has done in comparable circumstances in other countries.

President Reagan has made it clear that his objective is to drive the Sandinistas from power. One way to contribute to that objective is to help those Nicaraguans, other than the contras, who do not like the Sandinistas. The activities that might help these local opposition groups span a continuum in which one degree of severity merges almost imperceptibly into another.

We do not know all of the specific opposition groups, but we do know where to look for them - the anti-Sandinista newspaper La Prensa, the Roman Catholic Church, the business community, disaffected Nicaraguans generally. The help the CIA could give these groups might be as modest as spare parts for La Prensa's presses or a mimeograph machine for a church. At this level, the objective of the assistance would be simply to help the opposition survive so there would at least be some kind of political institutions in place in a post-Sandinista Nicaragua.

At the other extreme, help for the opposition would be directed more ambitiously to overthrowing the Sandinistas. It would include political advice and financial and other help in organizing strikes and demonstrations, so as to keep the country in a constant uproar.

Between the hypothetical mimeograph machine for a parish priest and the instigation of massive demonstrations, there are many levels of possible United States involvement. What may seem like a good idea as minimum help may generate a momentum that leads to something larger than originally intended.

There is risk associated with any involvement. If the American hand is exposed, it is at minimum an embarrassment for the US. At maximum it might be fatal for the recipient of the covert US aid. This risk increases as involvement grows.

There is no categorical answer to the larger question of whether the US ought to be doing this kind of thing at all. It is intervention in another country's internal affairs. There is a presumption against doing it, not only because it is distasteful and risky but also because we have solemnly promised not to do it in the United Nations Charter and the Charter of the Organization of American States, among other treaties. But the presumption may sometimes be overridden. The answer depends, in each case, on a delicate balancing of ends and means. As the means become more drastic, the end must become more transcendently important.

The Reagan administration, paradoxically, preaches minimalist government in the US but is extraordinarily activist abroad, particularly when dealing with small, weak countries such as Nicaragua. The administration so magnifies the threat posed by these poor, ragged people that in its view the end of getting rid of their government justifies almost any means.

Mr. Reagan is not the first president to get upset like this. During the Nixon administration, the CIA helped the opposition to President Salvador Allende in Chile.

The objective was said to be to keep the opposition alive until the post-Allende period. That period arrived in a hail of bullets three years before the Chilean electoral process called for it.

Now, 15 years after the overthrow of Allende, the Chilean people get to vote in a pseudo-election. They get to say yes or no to the dictator who has ruled them for these 15 years. If they say yes, they get him for eight years more. If they say no, they are promised another election next year. They have paid rather a drastic price for getting rid of an inept leftist president. For Nicaraguans, the price is already higher, and the leftist is still in office.

One of the things wrong with American policy in both Chile and Nicaragua was that a stubborn president was determined to do it his way (and in the case of Chile in total secrecy) in the face of divided public opinion. Whatever the morality of arguing for the pragmatic efficacy of covert action, the first requirement ought to be that such action further a policy that reflects a national consensus. If covert action is used to avoid the kind of debate that can build consensus, it will have pernicious long-range results, whatever its short-term success.

Pat M. Holt, former chief of staff of the Senate Foreign Relations Committee, writes on foreign affairs from Washington.