NEWS ANALYSIS : Allies Hope Attack Adds Muscle to NATO Threat : Balkans: The strike against the Bosnian Serbs was unimportant militarily, but West sees symbolic victory.

Although the destruction of a Bosnian Serb antitank gun by U.S. A-10 attack aircraft Friday was of little real military consequence, the United States and its allies hope to get a big diplomatic bang from the NATO air strike near Sarajevo.

The antitank gun, ancient and outmoded, was hardly very threatening. Bosnian Serb military strength in the war with the Muslim-led Bosnian government remains untouched.

But the Clinton Administration hopes that Friday’s incident will add to what is becoming a cumulative message for the Bosnian Serbs--that they have carried on their game beyond what the world is willing to take and are in danger of running out of cards to play.

The ways in which international pressure has intensified on the Bosnian Serbs include the allies’ decision to embrace a single peace proposal; the agreement by Serbian President Slobodan Milosevic to cut off aid to the Bosnian Serbs, and the decision by the major powers to vastly step up diplomatic pressure on the Bosnian Serbs.

Friday’s air action, officials said, helped to increase that pressure and to lend a touch more credibility to the allies’ threats to tighten enforcement of their weapons exclusion zones--and perhaps lift the arms embargo on the Bosnian government--if the Bosnian Serbs do not relent.

“It’s not so much the air action but the climate in which it took place that’s really important,” a key Administration official said shortly after the air strike was announced. “We hope this will help send a message that we are serious in what we say.”

Former Secretary of State Alexander M. Haig took a similar tack. “It’s all part of a great(er) plan,” Haig said in an interview Friday on CNN. The hope, he said, is that “all of these (will) combine with the air strike” to drive the message home.

Even so, the allies’ strategy is fraught with uncertainties. In the immediate term, there is considerable suspicion about whether the Bosnian Serbs will keep their post-strike promise to return heavy weapons they took in a pre-dawn raid Friday. The answer to that should be evident today, the deadline set for the weapons’ return.

There also is some nail-biting among Administration officials over whether Milosevic will follow through on his threat to cut off aid to the Bosnian Serbs if they continue to balk at the peace proposal. That, too, should be clear soon.

Key Administration officials were unable to say whether Russia will support the allies’ decision to launch an air strike. Moscow almost bolted from the peace effort after a similar air action earlier this year, partly because it had not been consulted.

Secretary of State Warren Christopher made it clear Friday that no one had told the Russians in advance this time either. Christopher said he tried to call Russian Foreign Minister Andrei V. Kozyrev on Friday afternoon but found that Kozyrev was on vacation.

Most important, despite the additional pressures that Friday’s air strike may have provided, there are no serious signs yet that the Bosnian Serbs themselves are prepared to give ground on the larger point and go along with the allied-backed peace proposal.

Indeed, some Western strategists suggested that, perversely, the Bosnian Serbs might even benefit from the attack if the specter of the allied air strike creates more sympathy among Serbs in Belgrade, undermining Milosevic’s ability to hold firm on his promise to the allies.

“We will have to wait and see,” one U.S. planner said.

If anything, the entire incident--in which the Bosnian Serbs commandeered U.N.-held weapons and the North Atlantic Treaty Organizations warplanes retaliated--was an opportunity for the allies, in more ways than one.

The West did not plan the NATO raid as part of any deliberate new allied policy. The attack came about only because the Bosnian Serbs violated the U.N. exclusion zone in a way that was too blatant for the allies to let pass.

The quick NATO response was not routine. It was possible because Yasushi Akashi--the United Nations’ cautious chief representative in Bosnia-Herzegovina, who usually stands in the way of any military action on the part of the allies--was on vacation.

The feeling at the Pentagon--and at NATO headquarters in Brussels--was one of elation. The military men had been frustrated over Akashi’s refusal to allow their warplanes to do their job, and there was bitterness over the fact that NATO’s credibility had been hurt.

To the extent that destroying an aging antitank gun restores NATO’s credibility, even temporarily, then Friday’s quick-response air strike can be considered a success, a U.S. policy-watcher said wryly.

But it may take months to see whether the action will have an impact that goes much beyond that.

Times staff writer Tyler Marshall in Brussels contributed to this report.