The case study today is U.S. policy in Nicaragua and the reading is from the Scottish bard, Robert Burns, a couple of centuries ago: "O wad some Pow'r the giftie gie us to see oursels as others see us it wad frae mony a blunder free us, and foolish notion."

The blunder I have in mind is the one that puts full faith in the deterrent effect of scare talk, of U.S. gunboats offshore, sonic booms in population centers, military maneuvers in Honduras, and (until Congress banned the funds) a "secret war" in support of the Nicaraguan counter-revolutionary forces, or contras. The foolish idea is that this will necessarily persuade the Sandinista government to halt its arms buildup and stop becoming "another Cuba."

It might -- if being "another Cuba" is what the Nicaraguan arms buildup is all about. But suppose the Sandinista leadership does not accept official U.S. protestations that it is interested in nothing more than "containing" Nicaragua, as administration officials put it? Suppose they seriously believe that Ronald Reagan's real aim is the one he has conveyed in occasional, careless lapses: to overthrow the Marxist- Leninist regime in Managua, by force if necessary? Suppose their war scare is real?

"That's utter nonsense," said Rep. Henry Hyde (R-Ill.), an out-front supporter of the administration, in a brisk exchange on "Face the Nation" the other day with Rep. Michael Barnes (D- Md.), a critic of the administration who heads the House subcommittee on Latin American affairs. Barnes had suggested that it would not be all that surprising if the Nicaraguans "might think that the United States might consider direct military intervention against Nicaragua; in the last 130 years, the United States intervened militarily in Nicaragua 12 times."

But even Hyde agreed with Barnes that the signals from the administration are "very confused." He saw "a very disturbing situation in terms of the public being informed as to what our policy is." So it does not seem farfetched, if an administration loyalist thinks the American public confused, to wonder whether the Sandinistas may not be confused as well. And that, in turn, would be reason enough to try to put yourself in the Sandinistas' shoes.

You are, let us say, a composite of the ruling Sandinista council. You fought a revolution in the name of a folk hero, Gen. Sandino, who took to the hills in the 1920s to resist the occupation of Nicaragua by U.S. Marines, returned when he thought it was safe to do so, and was killed by the same National Guard that propped up the U.S.-supported Somoza dictatorship for some 40 years.

You may not be worldly wise, but your sense of the U.S. role in Central America is not limited to Nicaragua. You may even know the numbers: 30 interventions since 1850, in Panama, Honduras, Guatemala, Costa Rica, etc.

It will not have escaped your notice that it was a Republican administration that conceived the idea of overthrowing Fidel Castro by underwriting and masterminding an invasion of exile forces and a Democratic administration that carried out the Bay of Pigs fiasco: The impulse is bipartisan. You probably know that Democrats John F. Kennedy and Lyndon Johnson specifically stated what Ronald Reagan now states: A second "Cuba" in this hemisphere would be intolerable.

It was 19 years ago that the Johnson administration landed Marines in the Dominican Republic to forestall "another Cuba." If the U.S. reputation for throwing its weight around the area needed updating, you have freshly in mind the Reagan invasion of Grenada. You will have noted that it was preceded by displays of photographs of airfields and other suspicious military installations, just like the public-relations campaign now intensifying over Nicaragua's military buildup.

You, the Sandinista government leader, may even be smart enough to have caught on to the theory of deterrence as a game that two can play. In that case, some part of the purpose and current pace of the Nicaraguan military buildup could be explained as the Sandinistas' way of saying that Nicaragua is not Grenada, where some 7,000 American troops were up against a force of roughly 700 Cuban combat engineers. The point is not lost on U.S. officials and military men. When asked about the odds on American military intervention, they are quick to note that the Nicaraguans have a 60,000-man army and a modest air force (Grenada had none).

Those comparative figures ought to be reason enough to give a certain credibility to the administration's denials of any intention to invade Nicaragua. But past history, the escalation of menacing gestures by the United States and the bipartisan congressional "confusion" about administration policy are reasons enough for the Sandinistas to misread U.S. intentions -- and escalate their buildup.

One way to begin getting off this escalator is for the administration to present a clear, consistent definition of its objectives in Nicaragua.