U.S., U.N. Pressured to Step In and Stop the Killing in Yugoslavia : Intervention: Despite the peacemaking rhetoric, the world appears helpless in the face of the ethnic conflict.

With the collapse of Western Europe’s first post-Cold War attempt at peacemaking, the United States and the United Nations came under growing pressure Friday to do something to stop Yugoslavia’s increasingly bloody civil war.

Canada called for the Security Council to act, possibly backed by military force, to blunt the Yugoslav army’s air and ground assault on the breakaway republic of Croatia. But the council, in a Friday meeting called for other business, showed little enthusiasm for armed intervention.

At the same time, the Bush Administration, backing away from its earlier objective of preventing the breakup of the Yugoslav federation, said the federal army and its allies in the republic of Serbia bear the greatest responsibility for the escalating violence.

Despite the resolute rhetoric, the world community seemed almost impotent in the face of the Balkan ethnic conflict. Outside military action promised only to increase the bloodshed, while diplomatic efforts to settle the dispute have proved fruitless.

Canadian Prime Minister Brian Mulroney called for immediate Security Council action and said the “peacekeeping forces of the United Nations, including those of Canada, should be placed at the disposal of Yugoslavia to stop the killing.”

Austria, Australia and Hungary have joined Canada’s call for Security Council action. France and Germany earlier had urged the United Nations to act, if only to voice its approval for a European peacekeeping force to intervene in Yugoslavia.

But Security Council delegates, meeting Friday to talk about the coming election of a new secretary general, said that no consensus emerged.

The Yugoslav army sharply escalated the fighting in Croatia on Friday in defiance of a cease-fire mediated by the European Community. That cease-fire was the 12-nation EC’s first attempt at international peacemaking, and its failure demonstrated that the organization has been unable to develop political influence to match its economic power.

Secretary of State James A. Baker III failed last June in a high-profile attempt to prevent the breakup of the Yugoslav federation--created in 1918 out of the ruins of the Ottoman Empire. Since then, the United States has withdrawn to the background, allowing the EC to take the lead in attempting to defuse the crisis.

Baker, in a June visit to Belgrade, urged Croatia and Slovenia to abandon their plans to secede and warned that the United States and the world community would reject any attempt by the two republics to achieve independence. Critics then complained that Baker had given a “green light” to the Serbian-dominated federal army to attack the breakaway republics.

But U.S. officials said Washington’s highest priority was to preserve the principle that national borders can be changed only by consent. U.S. policy-makers reasoned that, if Yugoslavia, a federation of six disparate republics, shattered into its component parts, other multinational states might do the same. Since then, the Soviet Union has come apart, overshadowing the Yugoslav disintegration.

In June, the United States had suggested economic sanctions against Croatia, Slovenia or any other secessionist republic. But Friday, State Department spokesman Richard Boucher made it clear that Washington now holds Serbia and the federal army responsible for the crisis.

“The U.S. believes that the cease-fire agreement signed earlier this week by the presidents of Serbia and Croatia and by the Yugoslav defense secretary represents a critical and perhaps final opportunity for Yugoslavia to turn back from its tragic course toward civil war,” Boucher said. “The present mobilization and deployment of additional (Yugoslav) military forces against Croatia represent the flagrant violation of the letter and the spirit of that agreement.

“The U.S. assesses actions by the Serbian leadership and the Yugoslav military aimed at redrawing by force the internal borders of Yugoslavia as a grave challenge to the basic values and principles” of European order, he said.

But when Boucher was asked what Washington plans to do about it, he said only that the United States would “continue to support the efforts of the EC.”

Washington was ambivalent about the Canadian proposal for Security Council action. Thomas R. Pickering, U.S. ambassador to the United Nations, would say only, “We will attend any meeting.” But he refused to say what position the United States would take.

Theoretically, the Security Council could impose economic sanctions or authorize the use of military force. But in the Yugoslav situation, it would be almost impossible to impose sanctions against one faction without hurting the rest of the country. And military action is impractical because U.N. forces would have to shoot their way in, and no nation seems willing to take the lead the way the United States did in the military action against Iraq.

David Hannay, British ambassador to the United Nations, said it is time to “consider whether we can bring the full weight of international opinion to bear through the Security Council.” But he said no action should be taken without the consent of the Yugoslav government.

“As much as we would like for all this to stop, we may be able to do no more than make sure this doesn’t spill over Yugoslavia’s borders,” said Helmut Sonnenfeldt, a former State Department and National Security Council expert.

He said that if the conflict continues, it might touch off a wave of refugees that could swamp facilities in neighboring countries. But, so far, that has not happened.

As long as the war seems to be confined to Yugoslavia, Sonnenfeldt said, the rest of the world “isn’t willing to try more extreme measures to bring it to an end.”

Otto Ulc, a professor at the State University of New York and an expert on Yugoslavia, said it is time for the United States to recognize that the Yugoslav federation will never be put back together.

“The depth of enmity and hostility between the Serbs and Croats is so great that the country has to fall apart,” Ulc said. “We should not applaud it, but we would accept it as a fact of life.”

Kempster reported from Washington and Toth from the United Nations.