Americans are sharply divided over the way President Clinton has handled the war with Yugoslavia, and a growing number of them also believe it was a mistake for the United States to get involved in the military conflict, according to a new Washington Post survey.

Now that peace talks have broken down, the president must not only persuade Yugoslavia to capitulate but must overcome obstacles at home to win public support for key elements of the NATO peace plan. Americans already were sharply divided over the president's decision Friday to send 7,000 U.S. ground troops into Kosovo to serve as peacekeepers once the fighting ends and Serb forces withdraw, the poll found. And most Americans believe that Yugoslav President Slobodan Milosevic will not live up to any peace agreement -- fears that likely were reinforced when talks were suspended last night.

The survey also suggests that recent moves toward peace in the Balkans had not yet yielded major political benefits for the Clinton administration, or had a direct impact on the 2000 presidential race.

Slightly more than half of those interviewed -- 54 percent -- said they approved of the way Clinton was handling the situation in Kosovo, unchanged from last month and down from 60 percent in April.

Clinton's overall job approval rating stands at 58 percent, largely unchanged from a Post-ABC News survey in late April. A Gallup poll for CNN and USA Today released yesterday put Clinton's job approval rating at 60 percent, up from a survey it conducted in mid-May but similar to its April finding. The Gallup survey also found that six in 10 Americans supported the peace plan that was announced Thursday -- but only one in five expected Milosevic and the Serbs to abide by the agreement.

As the Balkans veer between war and peace, public attitudes toward the war also may be in for similar shifts. But unlike the surge of good feelings that occurred near the end of the Persian Gulf War against Iraq in 1991, the Post survey suggests Americans are in a more somber and cautious mood about NATO's fight with Yugoslavia. Interviewing was completed just before NATO announced that talks had ended with no agreement.

Fewer than half of those surveyed -- 48 percent -- agreed that the United States "did the right thing" in getting involved in a military conflict over Milosevic's ethnic cleansing in Kosovo. That is down from 54 percent in last month's poll and the first time in a Post survey that a majority failed to support the U.S. decision to launch the air campaign against Yugoslavia.

At the same time, the percentage of Americans critical of the war has steadily increased, even following the announcement Thursday that Yugoslavia had accepted NATO's terms for peace. Over the weekend, 47 percent said it was a "mistake" for the United States to launch air attacks against Yugoslavia, up from 40 percent in early April.

"We need to extract ourselves from that situation as soon as we can," said Andy Driver, 37, of Zebulon, N.C., who was interviewed in the survey. "It was a bad decision from the start. I really don't feel that we should put U.S. military personnel in harm's way for a European civil war."

Monica Kellard, 37, of Attleboro, Mass., disagreed. "I'm glad we stepped in when we did. We cannot sit by and watch people get stepped on and murdered and do nothing. We had a responsibility to the world to help these people."

Nearly half of those interviewed -- 48 percent -- said they opposed sending 7,000 U.S. ground troops into Kosovo as part of a NATO peacekeeping force once a peace agreement is finalized and Serb forces withdraw from Kosovo. Forty-six percent supported the plan.

But interviews with survey respondents suggest that support could rise if Americans become convinced that troops are necessary to protect Kosovo's refugees, who consistently have been the administration's most effective weapon in the battle to win public support for its Kosovo policies.

"If it's necessary to help the refugees, then it might be okay," said Lisa Clark, 29, of Columbia, S.C. "But it's been such a mistake from the beginning. We have enough concerns and problems over here without having to go somewhere else."

Clark also wondered if NATO peacekeeping troops would be enough in the face of long-standing animosities between Serbs and ethnic Albanians, tensions exacerbated by the latest round of ethnic cleansing by Serb forces in Kosovo. "I think the hatred is so deeply embedded that it won't make a difference and there'll be more problems," she said.

The Post poll revealed Americans are united on one issue: More than eight in 10 Americans say Milosevic should be tried as a war criminal once the fighting ends.

"He has broken the law and should be tried, and I think he's guilty," said Jerry Foster, 54, of Salt Lake City.

Foster said he does not trust Milosevic to live up to any peace agreement that is eventually implemented. "His past record doesn't leave much room for trust." But Foster said he expects the Yugoslav Serbs to overthrow Milosevic. "He'll be overthrown before he's tried" as a war criminal, he predicted.

Thursday's announcement of a peace agreement has yet to alter the 2000 presidential race. Republican Gov. George W. Bush of Texas continues to hold a double-digit lead over Vice President Gore among registered voters in a hypothetical matchup of the two leading contenders.

Washington Post Poll

Q:Do you approve or disapprove of the way Bill Clinton is handling his job as president?

Approve 58%

Disapprove 38%

Don't know 4%

Q:Do you approve or disapprove of the way Bill Clinton is handling the situation in Kosovo?

Approve 54%

Disapprove 41%

Don't know 5%

This Washington Post poll is based on telephone interviews with 1,200 randomly selected adults nationwide conducted Saturday and Sunday. The margin of error for overall results is plus or minus 3 percentage points. Sampling error is only one of many potential sources of error in this or any other public opinion poll. Interviewing was conducted by TNS Intersearch of Horsham, Pa.