WASHINGTON--As a scholar of presidential success and failure, Littauer Professor of Public Administration Richard E. Neustadt watches the Nicaraguan aid debate unfold and wonders where it all will end.

"The president's rhetoric is going to make this harder and harder and harder, because this rhetoric says if this goes, it's dominoes; if this goes, Mexico goes," Neustadt says.

For the professor, there are familiar echoes--failures such as the Bay of Pigs and Vietnam, and successes such as the Cuban missile crisis.

Looking ahead to Thursday's House vote on President Reagan's $100 million aid package for the Nicaraguan rebels, Neustadt said Reagan might score a political victory "but it really is threatening to set us up on a course that is endless," a course he said could involve the United States in Latin American revolutions for years to come.

Neustadt's observations on the Nicaraguan debate come from the experience of a career spent studying presidential decisions--what went right and what went wrong and what could be learned from history.

In a new book, "Thinking in Time, The Uses of History for Decision Makers," Neustadt and historian Ernest R. May examine presidential decisions in events from Franklin D. Roosevelt through Reagan.

They cite John F. Kennedy's handling of the Cuban missile crisis and the Social Security compromise during Reagan's first term as success stories. Horror stories are more common, and include Vietnam, the Bay of Pigs invasion, President Carter's aborted arms control initiative in 1977 and his handling of the report of a Soviet combat brigade in Cuba in 1979.

In their preface, Neustadt and May acknowledge that many of the failures they cite occurred in the Carter years.

"Some readers are apt to think us unduly hard on the Carter administration," they wrote. "We go back and back to the Carter years like somebody tonguing a sensitive tooth."

They described Carter as a president whose "awareness of history was limited."

The Bay of Pigs invasion in 1961, in which a force of 2000 Cuban exiles, trained by the Central Intelligence Agency, landed on the island and were swiftly defeated and captured, was described by Neustadt and May as "the classic case of presumptions unexamined."

It was an instance in which Kennedy and his advisers failed to question such assumptions as their belief that the Cuban people would rise up against the government of Fidel Castro when the exiles invaded, the authors said.

Administration support of the Contras in Nicaragua often is compared with the Bay of Pigs.

In an interview, Neustadt cited the likely influence on Reagan of the "loss of China" in the 1950s when communist forces drove the nationalist government into exile on Taiwan.

That change, he said, "affected Lyndon Johnson on Vietnam," made him determined not to allow the communists another Asian victory.

As for Nicaragua, said Neustadt, "It may be playing out China again, but it also may be playing out Cuba again."

"There are a whole set of presumptions built in. It goes back to the Truman Doctrine and you can't lose countries, and to the hemisphere is our hemisphere," he added.

But while Neustadt made it clear he felt Reagan is heading in the wrong direction on Nicaragua, the professor praised the president's "great political instinct on when you have to cut losses."

He said "Reagan came into office with a small set of deep convictions about things that were based on his reading of history....Most presidents pick up their strong feelings as they go along. What they encounter in office gets them committed. He came in with three or four real strong commitments. I don't really think Central America was one of them."

Neustadt described Reagan's commitments as strengthening defense, lowering taxes and getting rid of the social programs of the Great Society.

But in the end, he added, "It all depends on what history, real history, events, are going to do to you. This guy has also got luck.

Think of poor Jimmy Carter, the second oil shock. What happens? He gets inflation. Reagan gets the oil glut followed by the collapse of oil prices."