Sides in Bosnia Urged to Disarm : Balkans: London conferees call for surrender of heavy weapons. Talks set for next week in Geneva.

Western governments Thursday called on combatants in the Balkans to surrender their heavy weapons and resume talks on the future of Bosnia-Herzegovina without conditions, effectively commanding them to undo five months of savagery that has killed thousands and made 2 million homeless.

The negotiations, to open in Geneva next week, are to be part of a vast new bureaucracy created by the conference delegates to tackle the Yugoslav crisis, one that they conceded was beyond their ability to resolve. It was also unclear if any of the conference’s demands on the combatants would be obeyed.

A 15,000-troop U.N. peacekeeping operation already deployed in some of the former Yugoslav republics will be expanded to protect humanitarian aid convoys and monitor compliance with a hoped-for cease-fire. The troops will also keep watch over tanks, mortars and artillery, which the fighting factions were told to turn over soon, the conference decided.

The conference also ordered a halt to military flights over Bosnia, a move aimed at the Serbian forces, since they are the only side in possession of combat aircraft.

Leaders of more than three dozen European and industrialized countries repeatedly declared that they would never allow aggressors to retain territory seized by force, but they appeared to grant Bosnian Serbs a right to negotiate over the 70% of the shattered republic they now control.

Bosnian Serb leader Radovan Karadzic agreed in a signed declaration only to withdraw from “a substantial portion” of the territory his forces have taken since war broke out in April.

Acting Secretary of State Lawrence S. Eagleburger acknowledged that the Bosnian Serbs had not agreed to relinquish all of their gains.

“That is not sufficient for the conference,” Eagleburger said of the partial commitment to withdraw.

“The United States will accept no agreement that does not involve return to the status quo ante” of prewar borders and integrated communities, he said.

Karadzic told a press conference that he is willing to negotiate over only 20% of his Bosnian holdings. He said his side is strong enough on the ground to enforce its will.

“We control all of our territory. We are ready for political solutions. Why would we delay a political solution when we are in a position to gain our objectives through political talks?” said the Bosnian warlord accused of directing the sieges of Sarajevo, Gorazde, Bihac and other Muslim strongholds.

British Prime Minister John Major admitted that the world “cannot rely on the goodwill of the parties” but said pressure would be exerted and intensified as necessary to force a political solution to the Balkans war.

Serbian leaders had hoped to see harsh economic sanctions lifted in exchange for their promises to stand down from the battles they are accused of having ignited. Serbian President Slobodan Milosevic angrily brushed past reporters after the conference, but other members of his delegation conceded that they came in for less punishment than they had feared.

“Serbs are partly satisfied. We at least know where we stand,” said Yugoslav Finance Minister Oskar Kovac, whose federal government is dominated by Serbs.

Major told reporters at a press conference that “sanctions will go when the killing stops and there is no need for the sanctions.”

Instead, the assembled leaders called for stricter monitoring of compliance by neighboring countries and a complete cutoff of Serbia in the event that fighting in Bosnia continues unabated.

After two days of debate among nations badly divided over the range of options for intervening in the year-old war, the conference ordered the immediate closure of detention camps and asked the United Nations to post a watch on Bosnia’s borders to guard against further smuggling of arms from Serbia and Croatia.

Policing the border is expected to have little influence on the arms situation, as huge arsenals of tanks, guns and ammunition were handed over to Bosnia’s rebellious Serbs by the Yugoslav People’s Army in May, and 80% of the former Yugoslav federation’s arms industries were in Bosnia, most of them now in the hands of the Serbs.

Delegates also discussed the possibility of establishing a war crimes tribunal to try individuals accused of gross human rights violations and threatened the Serb-dominated remains of Yugoslavia with “total isolation” if it failed to abide by conditions set by the conference.

But the world leaders refused to lift an arms embargo that has prevented the Bosnian government from equipping an army to defend itself against Bosnian Serbs who are fighting to secede and join neighboring Serbia.

Bosnia’s Muslim President Alija Izetbegovic endorsed the plan of action drafted by the participating governments even though it contained few specifics and fell far short of his appeal for Western military strikes to liquidate the Serbs’ armed advantage.

The international forum insisted that all displaced persons be allowed to return to their homes and be provided financial assistance to rebuild in areas where their homes have been destroyed. It was not clear how much such aid would cost or who would pay for it.

Eagleburger conceded that some refugees may be unwilling to return to villages where they have been subjected to atrocities, but he said all should be given that opportunity because otherwise the Serbian policy of “ethnic cleansing” would succeed.

“We are not about to create refugee camps that 20 years from now will still be refugee camps,” Eagleburger said.

Conference participants insisted that, if adhered to, the prescriptions they detailed in several documents would result in an end to the violence.

However, they admitted that enforcement was not assured and that the warring parties had previously committed themselves to similar principles.

This time the conference established an elaborate, bureaucratic structure that Major said was intended to “cajole and pressure the parties.”

The delegates ordered stronger measures to enforce wide-ranging sanctions imposed on Serbia and its ally Montenegro on May 30 in punishment for fomenting ethnic violence in Bosnia with the aim of conquering territory for annexation to a Greater Serbia.

The new forum for mediating the Yugoslav fighting will be a joint effort of the 12-nation European Community and the United Nations, supported by six different working groups and directed by a steering committee of 22 nations.

Overseeing the network of committees will be veteran U.S. diplomat Cyrus R. Vance, who is the special U.N. envoy in the Yugoslav conflict, and Lord Owen, a former British foreign secretary who was named Thursday to replace the retiring Lord Carrington as head of the EC peace talks on the Balkans.

Owen has a reputation as a hard-liner and has already advocated air strikes by the North Atlantic Treaty Organization against Serbian military targets.

His appointment may have dealt the Serbian delegation its greatest setback.

Before Owen’s appointment was made official, Karadzic said, “It wouldn’t be too wise to nominate Lord Owen to this task because he is already one-sided.”

Germany, Austria and Turkey led the international faction seeking harsher measures to curb the violence, which the conference blamed primarily on Serbs.

Major and U.N. Secretary General Boutros Boutros-Ghali, who co-sponsored the gathering that set back British taxpayers an estimated $8 million, sought throughout the conference to focus attention on matters all participants could agree on, seeking what one British government source described as “the widest possible” approval of measures.

One senior European diplomat said the British hosts “railroaded” through timid documents and summarily rejected calls for measures that would put more teeth into their declarations.

That mood of disappointment was expressed by dozens of demonstrators who stood vigil outside the Queen Elizabeth Conference Center to protest the slaughter in Bosnia and the international community’s failure to halt it.

Challenging the host prime minister to get tough with the Serbs, one placard in the forest of political appeals read: “Go Ahead, Major, Threaten Them With Another Peace Conference.”