As Washington's new evidence of Nicaraguan military buildup is being evaluated, prudence must be exercised to protect surrounding countries from any Nicaraguan military threat.The United States's hemispheric dominance gives it a key role in keeping the peace. Yet this role can be undercut by reinforcing the image of interfering bully rather than wise leader. Having drawn attention to the potential problem, the US can address it more effectively with the advice and cooperation of other members of the Organization of American States. Notable candidates in this instance might be such sturdy democracies as Mexico and Venezuela. They can help Washington see itself as others see it and join to prevent armed encroachments in the region.
Thus when the existence of a danger is agreed upon it can be met with the open means characteristic of democratic societies, not the covert acts which are again in the news.
The gathering of intelligence is not the issue here. This is essential to any country's national security. Knowledge can help to preserve the peace. It can shape constructive policies; even as lack of knowledge, witness US intelligence failures in Iran, can cause problems.
In all the controversy over arms buildup in Nicaragua the most careful intelligence is important. The Reagan administration has recognized the need for establishing credibility by going public with some of the evidence behind its buildup allegations. If this is persuasive to other nations in the region they could be expected to share US concerns and support US initiatives.
Yet, according to recent reports, the CIA is going beyond intelligence gathering and proposing plans for covert actions against Nicaragua. This week the Washington Post cited administration officials as saying that President Reagan had authorized a plan to start forming a commando force of up to 500 Latin Americans for paramilitary operations across the Honduras-Nicaragua border.
The reported initial budget of $19 million was described by some as not very much. But part of the controversy over US covert action in Angola involved a mere $1.3 million for recruiting mercenaries. Congress prohibited US intervention there in the mid-1970s.
The amount is not so crucial as whether the US should be going in the direction of more covert activities after all the ethical questioning of them -- and all their counterproductive effects -- as brought out during the various investigations of the intelligence agencies in recent years. The Senate Select Committee on Intelligence Activities, for example, found that, of five paramilitary activities it studied, only one appeared to have achieved its objectives. Cyrus Vance told the committee that covert actions should be undertaken ''only when absolutely essential to the national security.'' The committee concluded: ''The cumulative effect of covert actions has been increasingly costly to America's interests and reputation. The committee believes covert action must be employed only in the most extraordinary circumstances.''
Have such circumstances arrived in Central America? It is a serious question for Congress and the public to answer.Congressional oversight committees cannot countermand a presidentially authorized covert action. But, as former CIA director William Colby has pointed out, there is usually time during the implementation for them to make any doubts known to the White House so that it can call off an operation if it decides to do so.
In other words, if there is a Nicaragua plan, it need not be carried out. Under a Reagan executive order, the authorizing of covert actions is less restrictive than during the previous administration. The challenge is to exercise the greatest responsibility and accountability to ensure that the problems found by the congressional investigations are not repeated.