NEWS ANALYSIS : For a People Under Siege, Warning’s Aims Fall Short : Threat: Leaders act more out of embarrassment than out of a clear new resolve to stop the bloodshed.

The Western alliance’s ultimatum to the Bosnian Serbs to remove their heavy weapons from Sarajevo is not the decisive intervention for which Bosnians had hoped, not the end of Bosnia’s grueling war--and not even the end of the siege of its battered capital.

Rather, it is a limited action with limited objectives, launched out of Western leaders’ embarrassment at their impotence more than out of a clear new resolve to stop the Bosnian bloodshed once and for all.

President Clinton and other officials, anxious to avoid a quagmire of ever-widening military involvement, were careful to keep their commitments narrow and their promises small.

“We have . . . insisted that NATO not commit itself to any objectives it cannot achieve,” Clinton said.

The North Atlantic Treaty Organization’s decisions “are not intended . . . to end the conflict or to lift the siege of Sarajevo,” another senior official said. Sniper fire into the city’s streets and blockades of food and other supplies will not be affected, he acknowledged.

“We cannot guarantee that there won’t be any further shelling of Sarajevo,” a White House official added. All NATO can promise, the official said, is that “those responsible will pay a very heavy price.”

There were two reasons for the severe limits put in place by NATO.

One was the painful history of previous threats against the Serbs, from the George Bush Administration’s 1992 demand for an end to the siege of Sarajevo, to the Clinton Administration’s 1993 endorsement of a U.N. declaration that the city was a “safe area,” to NATO’s warning only three weeks ago that it was ready to use force. In every case, the Serbs paused to take NATO’s measure, discovered the threats were empty and resumed attacks on civilians.

But the second reason, which appeared to weigh even more heavily on Clinton, was his abiding fear that any new U.S. commitment to the fate of the Bosnians might turn into a step toward putting American troops on the ground--the one thing the President has consistently said he will not do.

Officials were careful not to promise any specific military outcome, such as an end to the shelling, for fear that keeping such a pledge might require more than they are willing to do.

Indeed, Clinton spent as much time stressing what he would not do in Bosnia as what he would.

“Our contribution to resolving the Bosnian conflict will be proportionate to our interests, no more and no less,” he said.

And he expressed the hope that, in the end, air strikes will not have to be launched at all--if the Bosnian Serbs comply with NATO’s demand peaceably.

If NATO does follow through on its threat--still a big if --it will be a landmark: not only the first time the West uses force to back up its warnings in the former Yugoslav federation but also the first time the Atlantic Alliance, formed 45 years ago to block a Soviet invasion of Europe, actually launches combat operations.

“Our nation has clear interests at stake in this conflict,” Clinton told reporters at the White House. “We have an interest in helping to prevent a broader conflict in Europe that is most compelling. We have an interest in showing that NATO, history’s greatest military alliance, remains a credible force for peace in post-Cold War Europe.

“We have an interest in stemming the destabilizing flows of refugees that this horrible conflict is creating. And we clearly have a humanitarian interest in helping to prevent the strangulation of Sarajevo and the continuing slaughter of innocents in Bosnia.

“These interests do not justify unilateral American intervention in the crisis, but they do justify the involvement of America and the exercise of our leadership.”

Clinton repeated a theme that he has often used on Bosnia and that he used again last weekend after a single mortar shell apparently fired by Bosnian Serb forces killed 68 people crowded in an outdoor market: Stopping the war is a problem for the Bosnians, not the United States, to solve.

“We must understand that in the end, this conflict must be settled at the negotiating table,” he said.

Clinton said he asked Secretary of State Warren Christopher to take a more active role in the U.N.-sponsored negotiations over a peace plan that would partition Bosnia into three states.

He described the U.S. role as talking to the Bosnian Muslims “to ascertain what their legitimate, bedrock requirements are and to share with them as clearly and honestly as we can what we think both the political and the military situation is. And then, using that as a basis, to go back to do what we can to facilitate an end to this conflict.”

In practice, a senior official said, this means that the United States will tell the Muslims that they should not try to gain more ground by fighting, but should instead seek to cut a deal soon.

At the same time, he said, the Administration hopes that the NATO military threat will help persuade the Serbs to accede to some of the Muslims’ demands for more territory.