A HIGH-stakes gamble by the Clinton administration to use both airstrikes and diplomacy in Bosnia is paying off for now.
American-led NATO airstrikes and a joint offensive by Bosnian Muslim and Croat forces have put the Bosnian Serbs under tremendous pressure to withdraw their heavy weapons from around Sarajevo and make peace.
With the Bosnian Serb army reeling from the airstrikes, Croatian and Bosnian forces have launched a joint military offensive that is taking large chunks of Serb-held territory - more than 500 square miles.
The joint forces took the strategic towns of Jajce and Donji Vakuf in central Bosnia this week. The fall of Jajce especially causes problems for the Bosnian Serbs. The town is the last Serb stronghold between advancing Muslim and Croat forces and Serb-held Banja Luka. Jajce also holds the main power plant for Banja Luka.
And after years of costly failed attempts, Bosnian forces on Sunday won control of a key supply route known as ''Route Duck'' that links Zenica and Tuzla - two of the largest Muslim-held cities in central Bosnia.
A few miles south of Donji Vakuf, an exhausted but exuberant group of soldiers was lounging in Muslim-led Bosnian government territory yesterday. On a nearby hillside, two modern Croatian Army battle tanks were seen along with Bosnian Croat trucks full of ammunition.
But the Muslim and Croat advances, clearly helped by the NATO airstrikes, are handing the Bosnian Serbs a powerful public relations tool against Washington's new initiative to both bomb and keep peace talks going.
This week's gains have resulted in new cries from Russia to stop the bombing. US Deputy Secretary of State Strobe Talbott arrived in Moscow yesterday to try to mend the rift between Russia and the US over the bombings. Nationalist members of the Russian parliament said Wednesday that they would travel to Bosnian Serb territory to act as human shields to prevent further NATO ''genocide'' against Bosnian Serb civilians.
Some US officials and the UN Security Council called for a halt to all offensive military operations in Bosnia Wednesday. But UN officials in Sarajevo say no clear plan - aside from halting NATO airstrikes - exists for halting the advance by Bosnian government and Croat forces.
UN officials and Western military analysts say the Bosnian offensives are in one sense helping Bosnian Serb military commander Gen. Ratko Mladic. General Mladic's argument that he cannot pull back heavy weapons from around Sarajevo because they would leave 100,000 civilians in Serb-held suburbs vulnerable to attack is being validated, they say.
UN High Commissioner for Refugee officials estimate that as many as 45,000 Bosnian Serb refugees are fleeing.
UN officials say the NATO bombing campaign is disrupting Bosnian Serb communications and confining some Serb units that could be used as reinforcements to their bunkers.
The officials also say that the Muslims and Croats are trying to enforce a Western-backed partition of Bosnia by force on the ground. ''All of the towns they have taken are supposed to be part of the [Muslim-Croat] federation according to the peace plan,'' says a UN official in Tuzla. ''By letting the towns fall now, [Serb authorities] don't have to ask all of those civilians to give up their homes voluntarily.''
THE mood in Muslim-populated Tuzla is euphoric, with trucks full of soldiers chanting Army slogans as they ride toward the front. The Muslim-led government forces failed to take Donji Vakuf three weeks ago, but with the apparent backing of Croatian tanks and artillery are clearly making headway.
Despite Russian rhetoric reaching its highest anti-Western pitch since the end of the cold war, it's unclear whether the US will take measures to stop the Bosnians and Croats.
For the Bosnian Army, the key is consolidating its positions in the event that the latest peace talks fail. ''They wanted to secure that road before winter,'' says a Western military official in Tuzla. ''But it seemed to be more of a short-term retreat by the Serbs than a victory by the Bosnians. I don't know what's going to happen next.''