Bosnia Serb Chief Signs Peace Plan; West Is Still Wary : Balkans: Karadzic bows to threats of Western military strikes. But president of self-styled parliament, which must approve treaty, calls it unacceptable.

ATHENS â€”  Bosnian Serb leader Radovan Karadzic on Sunday bowed to threats of Western military strikes against his forces by signing an international peace plan designed to end the bloodshed in Bosnia.

But because his signature came under duress and amid insistence by hard-line Karadzic compatriots that they still oppose the settlement, few of the diplomats and mediators involved in 11th-hour peace talks here were willing to characterize Karadzic’s concession as a breakthrough in the year-old war.

At an emergency peace summit in Athens, Karadzic put his signature to a plan that would divide Bosnia-Herzegovina into 10 provinces along ethnic lines and pave the way for the most ambitious peacekeeping operation in U.N. history.

More important, the plan aims to force Serbian leaders to abandon their drive to link Serb-held territory in Bosnia and Croatia with the republic of Serbia and to reverse their reviled policy of “ethnic cleansing.�

Senior U.N. officials expressed relief that the rebels had finally backed the negotiated settlement already endorsed by Bosnia’s Muslims and Croats, but they conceded that peace in Bosnia is still a long way off.

“The signing was the easy part,� said U.N. spokesman Fred Eckhart.

The Bosnian Serb parliament is expected to vote Wednesday on the plan signed conditionally by Karadzic, and the president of that self-proclaimed assembly again denounced the proposal as unacceptable.

Bosnian Serb politicians departing Athens made it clear the signature was not the end of the controversy.

Parliamentary president Momcilo Krajisnik told reporters that the Vance-Owen plan was “unacceptable as it stands.�

Even if the rogue legislature can be brought around in the next three days, the peace plan drafted by U.N. envoy Cyrus R. Vance and Lord Owen of the European Community would require massive population shifts to restore to government control nearly half of the territory seized by Serbian rebels.

Both Bosnian government and Serbian rebel leaders claimed they had scored a major victory after the agreement was signed, but they expressed diametrically opposed views about how it would be implemented.

“With this, the so-called Serbian Republic has proclaimed itself out of existence,� Bosnian President Alija Izetbegovic said in reference to Karadzic’s self-styled state, covering 70% of Bosnia.

But Serbian officials continued to refer to what they call the “Serbian Republic� even after the signing and insisted that their change of heart was made possible by last-minute concessions to the rebel Serbs.

Owen confirmed that the negotiators had moved to ease Serbian fears of vulnerability and retaliation in provinces where they would be a minority by agreeing to replace local troops with U.N. forces.

Karadzic signed the agreement only after marathon closed-door sessions with President Slobodan Milosevic of Serbia and President Dobrica Cosic of Yugoslavia, now made up solely of Serbia and Montenegro.

“It was a stormy session. There was a lot of shouting which could be heard outside,� said a conference source.

Milosevic and Cosic are believed to want some resolution of the Bosnian war because Yugoslav backing for the conflict has brought severe economic sanctions onto the Bosnian Serbs’ patron state. A tightening of the blockade last week has kept out most fuel and other vital supplies.

The Belgrade leadership has also been daunted by growing threats by the United States that force may be used to stop the Bosnian fighting.

U.N. officials said Karadzic’s resistance began to crumble when Milosevic and the Belgrade powerbrokers threatened to cut off military and food supply lines between what remains of Yugoslavia and Serb-held territory in Bosnia.

Greek Prime Minister Constantine Mitsotakis, the conference host, said he would push the United Nations to gradually lift sanctions against Yugoslavia as the peace plan is implemented in Bosnia.

A Greek Foreign Ministry source said Mitsotakis had threatened his Serbian allies with being “out in the cold� if they failed to sign.

Another conference source put it more simply: “They knew it was either sign or obliteration.�

Owen said he hoped the Athens agreement, if supported by the Bosnian parliament, would halt the Clinton Administration’s plans of action, “including military steps� against the Bosnian Serbs.

Vance stressed that he wanted to see rapid implementation of the plan now that all three parties have signed it, alluding to numerous promises made and broken by the combatants in the past.

The mediators said the plan would need about 70,000 U.N. troops to enforce. It stipulates that peacekeepers are to be drawn from Western Europe, the North Atlantic Treaty Organization and Russia--the latter a concession to the Serbs who share the Russians’ Slavic heritage.

Some military analysts claim that many more troops would be needed to police the thousands of miles of meandering borders in an attempt to ethnically partition a republic that is a patchwork of faiths and nationalities. Serbs in the thoroughly “cleansed� eastern areas are expected to balk at re-integration of the expelled Muslims.

Karadzic will have to persuade nationalists in his parliament that they should reverse their unanimous decision of last Monday to reject the Vance-Owen plan.

Special correspondent Silber reported from Athens and staff writer Williams reported from Vienna.