And he probably won’t have to: no one has seriously challenged Serbian aggression. Pictures of starved and battered inmates at Serbian-run prison camps stirred public outrage, pressuring Western governments to try to halt the atrocities. The response was a U.N. Security Council resolution adopted last week that authorized the use of force to deliver humanitarian aid to Bosnia. But there was no consensus on what military action might be used to protect relief convoys or who would take part. And it said nothing at all about how to stop the war or the Serbian rampage for national purity. A second resolution condemned ethnic cleansing, but fell short of establishing a tribunal to try war criminals.

The West may be feeling queasy about Serb atrocities, but it has no stomach to fight. There are problems of logistics, geography, objectives-and will. French President Francois Mitterrand has abandoned the bravado that propelled him to visit Sarajevo in June. “A purely military campaign would be a forbidding ordeal,” he told a reporter, adding, “Who would provide the troops needed?” Not the British. Alan Clark, a former British defense minister, wondered how anyone could tell families of dead British soldiers “that their son died not for the Queen and country but to prevent Serbs from killing Muslims.” Ditto the Germans. Defense Minister Volker Ruhe, citing constitutional limits on the use of force, said there was “zero” chance of committing German troops. Italy, too, backed off the military option. While the Bush administration has no intention of sending ground troops, NEWSWEEK has learned it is reconsidering its earlier refusal to support a lifting of the international arms embargo against Bosnia.

What is already clear is that two thirds or more of Bosnia is now in the hands of Serbs, who make up less than one third of the republic’s population. “Ethnic cleansing is not the cause but the aim of this war,” says Muharem Krzic, the Muslim president of the Democratic Action Party in Banja Luka. Last week, he says, anti-Muslim rioting in Bosanska Gradiska, some 30 miles north, claimed 500 lives. Maj. Milovan Milutinovic, a Bosnian Serb army official, blames the violence on a failed raid by Croats. “A few families of men killed on our side tried to take justice into their own hands, and six Muslims died,” he says. But an official for the U.N. High Commissioner for Refugees who visited the site claims local authorities abetted the riots. “It was like a party,” he recalls. “The crowd was going from house to house, throwing grenades in, lighting fires and laughing.”

How do the Serbs get away with it? Western inaction is only partly to blame. Most of the credit goes to Serbian President Slobodan Milosevic. His plan was brilliant and simple: under the cover of ethnic conflict, seize prodigious amounts of land. His tools were propaganda and arms. If Bosnian Serbs could be convinced they faced extinction, they would expel, terrorize and kill their neighbors.

Long before the fighting broke out last April, government-owned Belgrade Television began beaming its own version of the news into the living rooms of Bosnian Serbs. In a recent documentary, Muslims-referred to by Serbs as “Islamic fundamentalists,” “fanatics” and “Khomeinis”-were blamed for most of the world’s terrorism. One news report alleged Bosnian Muslims had fed Serbian children to the starving animals in Sarajevo’s zoo. Serbian publications, locally distributed, routinely call for and justify ethnic cleansing. When Politika, a small independent station near Belgrade, started presenting more balanced coverage of the war, Milosevic introduced a bill in the Serbian parliament to nationalize the Politika media empire.

The strategy to arm the Bosnian Serbs was more subtle. Milosevic had to find a way to achieve his violent objectives without being held directly accountable or seeming to violate Serbia’s diplomatic neutrality in the war. Until mid-May, local JNA (Yugoslav National Army) forces, which didn’t recognize the newly independent Bosnia, coordinated attacks on Muslims and Croats with Serbian paramilitary groups-which claimed to be acting on their own, not on Belgrade’s orders. But when the JNA was recalled by the new Yugoslavia, it left behind some 30,000 men, as well as artillery and tanks, multiple-rocket launchers and ground-to-ground missiles. The weapons flow from Belgrade never stopped, moving through Serbian-held northern Bosnian towns like Doboj and Banja Luka. In recent weeks NEWSWEEK reporters have spotted trucks loaded with weapons, including howitzers, moving across the Serbian border into Bosnia, and reconnaissance flights by MiG jets that the Serbian army inherited from the Yugoslav Air Force.

Milosevic has also provided support to Bosnian Serb political groups. Some, like the Serbian Chetnik Movement, have a distinctly military character. Others, such as Radovan Karadzic’s Serbian Democratic Party, have given Belgrade an important proxy in Bosnia. A 47-year-old psychiatrist, Karadzic travels several times a month from Pale, his mountain stronghold outside Sarajevo, to Belgrade, where he often meets with Milosevic. “They are certainly good Serbian patriots,” Yugoslav Foreign Minister Vladislav Jovanovic told NEWSWEEK. Translation: they see eye to eye on Greater Serbia.

But Milosevic’s system of patronage has dangerous liabilities. By so empowering local authorities, Belgrade may have started a war it can no longer control. “Milosevic cannot pick up the phone and have the shelling of Sarajevo stopped,” suggests a Belgrade-based Western diplomat. Karadzic’s power also is circumscribed. “He is not in full control of a lot of local communities,” says another Western diplomat. “The local commanders make their own choices.”

That is nowhere more obvious than in Banja Luka, the capital of the self-proclaimed Serbian republic. “We are very angry at Belgrade,” says Dr. Radislav Vukic, who is dressed in a Hawaiian shirt and electric-blue pants pulled low by the holster of an automatic pistol. “They allow a lot of Muslim and Croat women and kids to be supported and fed in Croatia while their husbands and fathers fight in Bosnia.” Vukic is the reputed architect of scores of village burnings and roundups of Muslims and Croats into detention camps. “They are weak Serbs in Serbia,” he says. “The only real Serbs are here in Bosnia.” Milosevic would surely disagree. He will have a chance to show his strength if he attends this month’s multinational meeting in London and sues for peace on his own terms. But he will still have to convince Western leaders that he can rein in the renegade forces he set in motion.