NEWS ANALYSIS : Clinton’s Challenge: Invasion Persuasion : Leadership: Americans need to feel Haiti is important to the U.S. So far the White House has hardly made that case.

President Clinton will address the nation tonight to explain why a U.S. invasion of Haiti, which appears imminent, is necessary and just.

He has a lot of explaining to do.

Americans seem to have no clear idea why the United States is about to embark on a sizable foreign military adventure.

“I hear there’s turmoil down there, political differences, I guess. Aristide, isn’t he a dictator?” asked 21-year-old Amy Inskip of Gettysburg, Pa., referring to democratically elected Haitian President Jean-Bertrand Aristide, who was ousted by a military coup three years ago.

Inskip said that the United States should stay out of Haiti because “it’ll be another Vietnam. We’ll be stuck there for years. I don’t think the White House has done a good job of selling anybody on anything.”

Becky Curtwright of Seattle also acknowledged knowing little about the situation in Haiti, but she expressed fear that the United States might get sucked into another quagmire like Vietnam or Somalia.

If the United States does invade, Curtwright said, “It should not be us by ourselves. . . . I don’t think the U.S. always should be responsible for carrying the world’s problems.”

The public anxiety and confusion are not surprising. Opposition is growing in Congress; on Wednesday the Senate opened a debate on the issue of an invasion. And only in recent days have Clinton’s aides started a public sales pitch.

Clinton himself has had virtually nothing to say on Haiti for weeks, passing up several opportunities--including a major address Friday in New Orleans before a large, friendly audience. In that speech, at a Baptist convention, Clinton spoke for 45 minutes about the decline in American values, never mentioning Haiti.

For a variety of reasons, the Administration has done less groundwork than usual to prepare the American people for the idea that their troops are going to be sent into battle overseas.

Officials had hoped that public threats would persuade Haiti’s junta leaders to step down. And Clinton has been distracted by a bitter fight over his crime bill, the death of his dream of passing a comprehensive health care reform proposal this year and a two-week vacation.

The President has devoted no time in recent weeks to public education about the American stake in Haiti and the case for U.S. military action there.

It shows.

Polls portray a public remarkably ignorant and confused about the situation in Haiti and about why the United States appears to be on the verge of sending troops into the impoverished Caribbean nation.

An ABC poll released this week found that only 28% of Americans believe that the United States has a vital interest in Haiti, while 62% said there is none.

And only 37% said they believe that the United States and its allies should use military power to restore democracy in Haiti. Support for intervention actually has fallen through the summer--from 45% in favor of an invasion in June. Opposition to military action in Haiti has been steadily rising, from 50% in June to 54% in July to 56% this week.

It seems that the more Americans learn about Haiti, the less inclined they are to see American blood shed there.

“I don’t want them to go in. I’m against it,” said Tom Barrows, who owns an Atlanta office supply store. “Getting into Haiti will be easy. The trick will be getting out. This is not Grenada.”

To be sure, popular uncertainty and skepticism about sending combat troops overseas are not unusual in American history.

Public support for the Korean War was never strong, and Franklin D. Roosevelt was far ahead of public opinion when he began helping the British during the early months of World War II. Vietnam tore the country apart.

When troops are actually committed to combat, public opinion almost always rallies around the flag--at least for a time. Clinton is counting on it.

“I think that the American people have a great tradition of rallying around their President (when) U.S. troops are involved, and there’s, I think, a long precedent of that,” said White House Press Secretary Dee Dee Myers.

Yet failure to build a solid public foundation under military intervention when the national interest is not dramatically threatened has cost Presidents dearly in the past. Korea and Vietnam played a role in the decisions of Harry S. Truman and Lyndon B. Johnson not to seek reelection.

And Clinton’s current political weakness, combined with the underlying difficulties of the situation in Haiti, makes the danger of a public backlash especially great this time.

“If it’s successful and casualties are extremely low, you’ll find general support for it,” said John Mueller, a political scientist at the University of Rochester in New York and author of “War, Presidents and Public Opinion.”

“But there isn’t much of a big bounce in these things. Everyone agrees that Haiti is a small problem. If he solves it, he gets minimal credit, because it’s so small. But if things go bad, it’s a total disaster.”

Clinton’s failure to lay the groundwork for involvement in Haiti stands in striking contrast to the tactics of his immediate predecessor.

For months before the December, 1989, invasion of Panama, the George Bush Administration filled the airwaves with threats, warnings and explanations of the crimes of dictator Manuel A. Noriega and the American interest in deposing him. Pentagon and State Department officials let few days pass without recounting another Panamanian atrocity or threat against American military and civilian personnel there.

The drumbeat resulted in dramatically rising public support for action against Noriega. In October, 1989, a Gallup Poll found that only 26% favored using U.S. forces to invade Panama. But on Dec. 20, 1989, the eve of the Panama invasion, 58% of those polled by ABC News favored the U.S. overthrow of Noriega.

Following Iraq’s invasion of Kuwait in August, 1990, the fall and winter brought an almost daily public countdown on the potential approach of a Persian Gulf War, leading up to a widely publicized and highly informative congressional debate that galvanized opinion on the impending action.

In contrast to the falling support for an invasion of Haiti, public sentiment in favor of attacking Iraq grew dramatically in the weeks preceding the Gulf War.

This was the result, at least in part, of a concerted effort by the Bush Administration to convince the American people of the necessity of military action against Iraqi President Saddam Hussein.

Marlin Fitzwater, communications director in the Bush White House, said that Bush and other senior officials identified three or four easily understood reasons for going to war against Hussein and repeated them endlessly. Clinton has yet to do anything comparable with regard to Haiti.

“What won’t work is trying to do it in one shot,” Fitzwater said, referring to Clinton’s expected attempt tonight to justify the use of force in Haiti. “You can’t give one speech to the American people and forget it. . . .

“Here we are on the verge of an invasion, and nobody knows why,” Fitzwater said.

Evidence of this can be found on street corners and in shopping malls.

Sue Scott, 48, of Jacksonville, Fla., sitting on a bench outside an ice-cream parlor in Gettysburg, Pa., was asked what she thought about the prospect of an American-led war in Haiti.

“I don’t have any opinion. I haven’t heard much about it,” Scott said. “Isn’t it that we want somebody back in--or was that another country?”

Times staff writers Ronald Brownstein in Houston and Aaron Nathans in Gettysburg, Pa., and researchers Edith Stanley in Atlanta and John Beckham in Chicago contributed to this article.

Polls Find Lack of Support

Americans do not believe the United States has a responsibility to send troops into Haiti, national polls have found.

ABC

U.S. and allies should take all action necessary, including military force, to restore a democratic government in Haiti: Agree: 37% Disagree: 56% Should the United States lead an invasion of Haiti? Yes: 23% No: 73% ***

CBS / New York Times

U.S. troops to Haiti in order to remove the military and restore elected President Aristide: Favor: 29% Oppose: 66% Based on survey of 1,161 adults Sept. 8-11. Margin of error is 3 percentage points.