UN to Tighten Sanctions As Bosnia's Serbs Advance

CAN anything short of outside military intervention halt the war in Bosnia-Herzegovina and persuade Bosnian Serbs to give up a major chunk of the land they have captured?

Diplomats here hope that NATO's enforcement, starting today, of the United Nations ban on all military flights over Bosnia will send at least a symbolic message of the importance of reaching a diplomatic solution.

Security Council members also hope to step up the pressure by passing a resolution today that commends a UN-sponsored peace plan as it tightens year-old economic sanctions on Serb-dominated Yugoslavia. The resolution bans all shipments of supplies to or through Yugoslavia, except for humanitarian goods approved by the council in advance. New UN determination

One Western diplomat says Council members are "irritated" by the Bosnian Serb parliament's defiant rejection last week of the peace plan drafted by UN envoy Cyrus Vance and his European Community counterpart, Lord David Owen.

That plan has been accepted by Bosnia's Croats and Muslims. "I think there's a real determination now on the Council to see that the sanctions go through in fairly strong fashion," says the Council diplomat.

Yet Russian officials, who face strong domestic pressure not to cut off their traditional Serb allies, could threaten the vote. Deputy Foreign Minister Vitaly Churkin, Moscow's special envoy to the Balkan conflict, said after a meeting in Belgrade with Serb and Bosnian Serb leaders that too swift a move on sanctions could intensify the fighting. Russian President Boris Yeltsin sent a letter to President Clinton apparently in an effort to get the vote delayed, diplomats said.

Tougher sanctions are unlikely to have any direct effect on the ground war. Yet the control lines between Serbian President Slobodan Milosevic and Bosnian Serb leader Radovan Karadzic remain strong, many analysts say.

Mr. Karadzic knows he needs Belgrade's sponsorship and patronage, says Otto Ulc, an expert on Eastern Europe at the State University of New York at Binghamton.

If those applying the sanctions "really mean business," he says, the impact on Serbia could exceed the point of tolerance within two or three months.

No major power is ready to commit troops to stop the war in Bosnia-Herzegovina. Yet the reaction of horror to events there is universal. "You can't just stand by and do nothing," insists one Western diplomat.

Top US officials have been conferring on options. Most talk centers on possible air strikes and an exemption from the UN arms embargo for Bosnian Muslims.

US officials say Washington would not lift the embargo unilaterally. Yet any such move in the Council would face strong opposition from Britain, France, and Russia. Mr. Vance and Lord Owen warn that exempting Muslims from the embargo could widen the war and that Croatia might siphon off such arms imports before they reach the Muslims.

Yet Sen. Joseph Biden (D) of Delaware, who has been on a five-day, fact-finding trip to the Balkans, says the arms embargo must be lifted and that President Clinton should use his good offices to prevent a Council veto.

"You could do it [exempt Bosnian Muslims from the embargo] in sort of a sneaky way like the Serbs have been doing and simply, with a wink and a nod, allow the weapons to come in," says Janusz Bugajski, an expert on Eastern Europe at the Center for Strategic and International Studies. Many Islamic states, he says, are willing to supply and pay for the arms. The Croatians could be threatened with tighter sanctions themselves if they tried to intercept the weapons, he says. Diplomacy first

Still, a diplomatic solution is widely viewed as far preferable to continued fighting if Bosnian Serbs can be kept from using the talks as a delaying tactic. "My feeling is that there is still hope for the Vance-Owen plan ... because the Serbs are divided on this," says Mark Nelson of the Carnegie Endowment for International Peace.

Last week Karadzic protested to Vance and Lord Owen that the Serb position has been "widely misrepresented." He said he is ready to return to Geneva for "direct talks" and to renegotiate the Vance-Owen map which divides Bosnia into 10 highly autonomous provinces.

One possibility is a shift to international control of part of a corridor in northern Bosnia that Serbs want to control and consider vital to their supply lines. Says one diplomat close to the talks: "If Milosevic and Karadzic want to see this whole thing resolved, they can do it."