"Please call me about Nicaragua. This will be a friendly chat."

FBI and other intelligence agents across the country have begun leaving their calling cards in the mailboxes of citizens concerned with the direction of U.S. policy in Central America. Agents have also been visiting people at work and talking to neighbors and friends. Active opposition to U.S. policy is apparently not a prerequisite for a visit. A law student in New York who merely attended a meeting on Nicaragua was rewarded with an FBI visit.

According to FBI Director William H. Webster, his agents have made at least 100 such visits. Webster -- whose level-headed stewardship of the FBI I greatly value -- says that the agents are always polite and that the visits are never threatening.

But no matter how friendly the visits may be, they raise several troubling questions.

First, why now? The proper role for the United States in Central America is one of the most hotly debated issues facing us today. Many Americans have serious doubts about the wisdom and efficacy of our policy in Nicaragua, El Salvador and other countries in the region. More and more people are traveling to Nicaragua to see for themselves what is going on there and to form their own opinions.

But when an FBI agent comes to your door, no matter how polite he or she is, there's a subtle message that you've done something wrong. You've traveled to a country whose leadership our president would like to see cry "uncle." You've been to a meeting. You've questioned American foreign policy. At the very time when national debate is most intense and public participation is most important, you're being told subtly not to debate and not to participate.

This leads to my second question: At whose direction is this happening? Webster says the FBI has received "specific taskings" from the National Security Council and the Central Intelligence Agency to conduct a number of interviews. Does this mean that the NSC, composed of the president, the vice president and the secretaries of defense and state, or the director of Central Intelligence, a presidential appointee, has instructed the FBI to target opponents of U.S. policy in Central America? All too frequently in our recent past, makers of foreign policy have sought to enlist the FBI in squelching domestic opposition. We cannot allow a return to such practices.

Third, what is the sense of it all? Does the administration really feel that the Sandinistas are a threat to our national security? And even if they were, what does the administration hope to learn from the people it has been questioning? A person genuinely and actively opposed to U.S. policy in Central America is unlikely to answer questions posed by an FBI agent, while a person only peripherally involved is unlikely to know much of value to our intelligence services.

In most of the cases that have come to our attention, the person has answered the FBI's polite request for a chat with a polite "no." Does the FBI agent then file a report: "Subject contacted. Refused to cooperate"? How about the woman who suggested that the Defense Investigative Service agent who called her reread the Constitution? Is there now a file on that woman stating, "Subject contacted. Refused to cooperate. Cited the Constitution"?

If the Nicaraguan government has launched a hostile intelligence operation in this country, will we crack it by interviewing members of humanitarian groups and Americans who have traveled to Nicaragua? For the third year in a row, the administration is asking Congress to approve substantial increases in the FBI's foreign counterintelligence budget. If the current corps of agents has tim to attend public meetings on Nicaragua and to visit travelers returning from Central America, it suggests that the FBI has altogether enough agents already.

The apparent futility of this pattern of questioning brings me back to my first question: Why now? At the very time that Central American policy and aid to the contras are being debated and decided, FBI agents are visiting citizens involved in the debate. It seems inevitable that there will be a chilling effect and some will withdraw from the debate. I do not believe that the FBI should be made a party to this.

Let the FBI pursue directly any Nicaraguan agents operating in this country. But let it not, by virtue of "friendly" visits, become involved -- or create the perception that it has become involved -- in what remains a debate on foreign policy.