There is something unnerving about aging administration officials talking to the press like simpering ingenues of the 1940s. Wide-eyed and guileless, they avow chastity in the Nicaraguan adventure. Provoking military exchanges in Central America? Trying to overthrow the Nicaraguan government? Breaking the law by bankrolling the "contra" guerrillas who used to be Nicaraguan National Guardsmen? Helping people shoot their way into office? Little me? Heaven forbid.

What the administration says it's doing is trying to stop the flow of arms from Nicaragua to El Salvador's guerrillas. This is a little hard to swallow when intense-looking men in Miami and Honduras explain, on television, that what they're doing is trying to overthrow Nicaragua's government. The illusion is further undermined by U.S. officials' continuing public comment that the Salvadoran guerrillas provide for themselves largely through purchase or theft from their enemies, the Salvadoran government forces, which we also supply.

The administration doesn't deny instigating or paying for its "secret" war. It only denies that it is violating the Boland amendment, which forbids any U.S. assistance in overthrowing the Nicaraguan government. It maintains that masses of arms are flown over the sea nightly to Salvadoran rebels. But it doesn't make clear how sending foot soldiers across the border from Honduras to shoot up rural communities in Nicaragua will stop the air supply.

It is also hard to figure how reconnaissance sorties and intelligence gathering by U.S. personnel will stop air shipment of arms. One thousand photos, a thousand radio intercepts and purloined documents won't ground a single plane, by themselves.

This semi-overt "covert" war is mighty murky. All the American people know is that "we" are engaged. That's the overt part. The big secret is what is being given, to whom, at what cost, for what purpose.

Another piece of the secret is who decided to take these actions. Perhaps it is part of the Haig legacy. Secretary of State George Shultz doesn't give a fig for anything south of Texas, so it's unlikely that he took any initiative. There is sufficient leakage around the edges to ascertain that some CIA officials view this undertaking with a jaundiced eye. Maybe the president got the idea from Reader's Digest.

It doesn't seem much to ask of a democratic government: who did it?

The president has already put us into two wars down south. But the polls consistently demonstrate that they are not supported by the public. Poor people are falling dead from our bullets and the machete-wielding soldiers U.S. tax dollars underwrite. The Argentines have pulled out; Honduras lends its territory; Guatemala is hustling its own case. Who are our allies in this debacle?

A couple of weeks ago, Rep. Tom Harkin and 73 of his colleagues in the House introduced a resolution of inquiry to find out the who, where, why and when of administration involvement in Nicaragua. It was referred to three committees --Armed Services, Foreign Affairs and Intelligence. They must act and report to the House. The resolution asks the pertinent questions in this matter. If the House passes it, the president "shall furnish" the answers within 10 days. As Rep. Jim Wright said to one of the "contra" leaders last week, "I do not believe financing the invasion of another country is what the United States should be doing."

Reps. Edward Boland and Clement Zablocki have a bill that ought to knock the relationship with the "contras" out of the box. It prohibits secret funding of military and paramilitary groups that want to harass, destabilize or overthrow any of the regional governments. Instead, it authorizes $30 million this year and $50 million next year for open military assistance, only to governments and only to help them stop military supplies from Cuba and Nicaragua from getting to or through their countries. The participating governments can't move the assistance on to others, nor can they conceal its source.

While the bill is explicit on the military- paramilitary side, it does not cover covert political actions by the administration. It would still be possible, apparently, to pass money and "advice" to anyone. Is this a loophole through which the administration could continue to hand over cash so that the "contras" or others could simply buy what they want from the black market? If so, harassment, destabilization and efforts to overthrow governments could continue with secret U.S. political aid, unless there are clear prohibitions on political activities.

While the House leadership is prepared to move it quickly, the Senate must also act and the administration still has a given number of days before the bill comes into effect. And it is wise to remember that between passage of legislation cutting off military assistance to Chile and its signing by the president, there was wild contract-signing and obligation that kept the pipeline filled and flowing for years. There should not be a repetition, all these years later, in the interval.

For some reason, the conventional wisdom on Capitol Hill seems to hold that the Zablocki-Boland bill makes the Harkin resolution of inquiry unnecessary and that the answers to the questions don't need to be given. It could be that was the price that had to be paid to get rid of covert military assistance. But it might be too high a price if it closes out the questions.

This bill is a firm step in the necessary direction in spite of its imperfections. And the resolution of inquiry is equally important. It may be more important, in fact, because until we have the answers to its questions, other legislative actions, congressional hearings and opinions are based on fragments of facts in contention. Decisions of the public and Congress about U.S. policy should be based on as much real information as they can get. The administration has that information, and we need to know it.