WASHINGTON -- The U.S.-led bombing of Serbian positions in Bosnia -- NATO's most powerful assault ever -- will continue, for days if necessary, to force the Bosnian Serbs' leader to the negotiating table, officials said yesterday.
"He has got to learn the lesson and derive a lesson from the actions over the last 12 to 24 hours, that he has got to turn to the negotiating table," said Nicholas Burns, the State Department spokesman, referring to Radovan Karadzic.
"The tide of war has turned against them. . . . They cannot seek a military solution to this conflict. They have to seek a political solution."
If Dr. Karadzic remains defiant, the attacks might even be intensified, according to NATO and U.S. commanders. Even as the airstrikes were launched, the Pentagon ordered more planes to the area.
"We are going to keep it up until the Serbs yell 'uncle,' and get the message," said a Navy officer. Another said: "The ballgame is now in the Serbian court, and the bombs are on our planes. They are not going to stop until they feel the Serbs get it."
Throughout the day and night yesterday, wave after wave of Allied planes, including U.S. Air Force, Marine and Navy jets, attacked Serbian air defenses, communication posts and ammunition depots, while United Nations artillery fired on Serbian positions around Sarajevo. Jets from other NATO countries struck at Bosnian Serb air defenses near Mostar in the west, Gorazde in the east and Tuzla to the north.
The first wave of jets targeted ground-to-air missiles sites, chosen to make the skies safer.
Later, a French Mirage 2000 was downed by a missile near the Serbian stronghold of Pale. The two-man crew parachuted out of the plane, and last night were reported to be safe on the ground.
But rescuing them, according to a Marine officer, will be difficult because of heavy air defenses, including shoulder-fired missiles and optically guided anti-aircraft weapons. A French operation to reach them overland is being considered, according to the official.
Five observers from the European Union, traveling south of Sarajevo, were killed. But it was unclear whether they were victims of the NATO attack or the Serbs.
By day's end, officials in the Pentagon said that heavy damage had been inflicted on most of the targeted facilities. One senior officer cautioned, however, that it was "temporary, temporary, temporary."
Adm. William A. Owens, deputy chairman of the Joint Chiefs of Staff, told reporters at the Pentagon: "The success of the strikes was apparently very good."
Another officer said the cloud cover was so thick over Bosnia that damage assessments were based mostly on pilot reports rather than on satellite or surveillance photographs. Several targets will be struck again today, he said.
"The message is that we can reach and touch them," said a Navy officer.
The NATO attack came in response to a Serbian mortar attack Monday on a marketplace in Sarajevo that left 38 civilians dead and more than 100 injured.
As planes from five NATO nations -- mainly the United States -- continued their raids, all eyes were on Dr. Karadzic, whose initially declared that the bombing would strengthen the resolve of his troops and could disrupt the peace process.
According to analysts, if the bombing and shelling convince Dr. Karadzic that he cannot win a military victory, he could show he has "got the message" in several ways:
* Announcing his readiness to negotiate an end to the civil war.
* Withdrawing what is left of his armor and artillery after yesterday's raids from the weapons-exclusion zone around Sarajevo and other U.N. "safe" areas.
"The bottom line is that the Serbians aren't going to shoot any more mortars on civilians," said an officer in the Pentagon.
The Clinton administration is linking the military action to its latest diplomatic initiative, gambling that the one will not destroy the other. Officials said a "window of opportunity" for peace is now open, with prospects for a settlement better than at any time since the Clinton administration took office.
Hours before the attacks, Dr. Karadzic and the self-proclaimed Bosnian Serb "parliament" sent messages indicating that they would be willing to consider the latest peace plan. While officials welcomed the response, they said that it was too little and too late to call off the bombing.
A settlement in Bosnia, after four grueling years of war, would give Mr. Clinton, who has been accused of lacking international leadership, an important political boost as he prepares to seek re-election next year.
In another sign that the political toll of the crisis could be easing for Mr. Clinton, Republican Senate Majority leader Bob Dole of Kansas welcomed the NATO air and U.N. artillery attacks and said he was willing to consider postponing action in the Senate to lift the arms embargo on the Bosnian Serbs -- "if the recent Western attacks prove to be part of a new and effective policy which leads to a just and lasting peace settlement," he said. "However one day of military action does not make up for three years of passivity and failure."
Mr. Holbrooke has been touring Europe to present the Clinton administration's peace plan, which includes a revised map giving the Bosnian Muslims more ground around Sarajevo and ceding to the Serbs the enclaves of Srebrenica and Zepa, which they recently conquered.
Will the bombing bring the Serbs to the negotiating table?
"I think it has a better chance of working this time than ever before," said Daniel Nelson, a professor of international studies at Old Dominion University and a former foreign policy adviser to Rep. Richard A. Gephardt, a Missouri Democrat, when he was majority leader of the House.
Pointing to "a confluence of events," including recent battlefield successes by both the Croats and Bosnian Muslims, the shock over the recent deaths of three U.S. diplomats on their way to Sarajevo, and the heavy airstrikes, he said: "All these things brought together are propelling this to a point where it might well work."
Dov S. Zakheim, political-military analyst with the Center for Strategic and International Studies and a former Pentagon adviser, said that the sudden assertion of U.S. "leadership" on both the military and diplomatic fronts in Bosnia was "critical."
"It tells Karadzic he now has to react to American leadership, to more and more American involvement," he said. "The U.S. is really running the show now. The thing about this attack is it is what we wanted. The British and French were a little more reluctant. But we got our way."