The Clock Runs Out On Bosnia Cease-Fire As All Sides Shun Talk

A FOUR-MONTH cease-fire brokered by former President Jimmy Carter ended amid renewed skirmishes at noon yesterday in Bosnia, and analysts say the only side approaching desperation in the conflict is the West.

With a crucial summer ahead of it, the United Nations and its Western backers are being steadily transformed from the conflict's powerful mediator to its helpless spectator.

France, Russia, and Britain -- the three most powerful nations with peacekeepers in Bosnia -- are threatening to pull their troops out. And diplomats from what was once hailed as the world's most powerful negotiating bloc -- the five-nation ''contact group'' -- continue to be snubbed by Bos-nian government and rebel Serb officials who refuse to meet with them. Efforts yesterday by UN Special Envoy Yasushi Akashi to extend the cease-fire were rebuffed by both sides.

And in a another snub, the generally Western-backed Croatian government launched an artillery and infantry attack on rebel Serbs yesterday morning that diplomats warn could widen fighting in the region. ''It's very bad news for the UN,'' says Paul Beaver, Balkans analyst at the London-based Jane's Defence Weekly -- a global report addressing defense issues. ''I see the whole thing breaking down.''

Mr. Beaver says the end of the cease-fire and the new Croatian tack shows that the UN mission in the former Yugoslavia remains stunted by a lack of political will. A weak mandate from the Security Council, a lack of sufficient military force on the ground, and a continuing refusal to use force in the conflict will prevent the UN from ending this fighting in Bosnia.

Beaver warns that the UN is succeeding at ''stopping people from completely killing each other,'' but the resolve of its prime backers in Bosnia -- Britain and France -- is weakening.

After the killing of two French soldiers in recent sniping attacks, France, which has the largest number of troops in Bosnia, is threatening to withdraw. Britain, the second-largest troop contributor, recently said it would like to withdraw its forces by September if replacements can be found. And Russia also warned it would withdraw its troops if fighting resumed.

Western diplomats caution that a withdrawal is not imminent, but say continued fighting that leads to more UN casualties could prompt a pullout. ''Anything can happen in Bosnia. It depends on what the Bosnians try to do,'' says a Zagreb-based Western diplomat. ''If they continue to go for small strategic gains, they may do well ... but the [UN-troop-protected safe havens] have always been vulnerable.''

In a surprise move, the Bosnian government broke the cease-fire, negotiated by former President Carter, last month by launching dual offensives in central Bosnia. Strategic high ground and communications towers were captured near the Muslim-held towns of Travnik and Tuzla. A much-threatened Bosnian Serb counterattack has failed to materialize.

''[Bosnian Muslims] are very confident that they have the ability to hold their own now,'' Beaver says. ''They feel that if the arms embargo is lifted, they will be able to end the war.''

In neighboring Croatia, the generally pro-Western but increasingly defiant Croatian government's surprise attack on rebel Serbs has diplomats scrambling for a solution. Croatia is becoming frustrated with the UN's inability to negotiate the peaceful reintegration of nearly one-third of Croatia seized by rebel Serbs in 1992, and threatened to throw out UN peacekeepers last month. ''We don't see this as a calculated, pre-planned attack. We see it as a response to specific incidents,'' says the Western diplomat. ''So far, we see no new fighting in other areas.''

During the last week, a strategic highway running across Serb-held territory has been closed twice following incidents that left three Croats and one Serb dead.