Finally, at 5 p.m., after they selected four targets, the mission got underway. Four groups of four aircraft each – U.S. A-10 Warthogs, Dutch F-16s, French Mirage F-1s and British Jaguars – took to the skies. By that time, the weather over Bosnia had gone from bad to miserable; a cloud cover at 4,000 feet and intermittent rain made it hard to see the targets, much less to communicate with U.N. ground controllers. When the skies cleared at 6:30 p.m., the lead pair of A-10s spotted something to hit and emptied 600 rounds from their 30-mm cannons, shattering a World War II-vintage antitank gun. At that point, the Serbs cried uncle and the U.N. command called it quits.

Snafus aside, the Serbs seemed to get the message. Hours after the strike, they handed back the weapons they’d stolen, in violation of the 12.5-mile exclusion zone imposed on Sarajevo in February. That theft capped weeks of brazen defiance designed to test the allies’ resolve. Serbs stepped up their sniping in the capital, closing off the airport to relief flights since late July. They attacked a 10-truck U.N. convoy, killing a British soldier. Last week the Bosnian Serb Parliament again rejected a Western peace plan that would have required them to give back about one third of the territory they now hold, declaring, “Acceptance of such a thing would represent a masochistic crime at which the Devil would laugh.”

But the Devil isn’t laughing anymore. Serbian President Slobodan Milosevic, who incited and supported the Bosnian Serbs, now seems determined to end the war. Eager for the West to lift the crippling sanctions on Belgrade, Milosevic has turned against his proteges until they embrace a peaceful settlement. His rhetoric – calling Bosnian Serb leaders “war profiteers” who were “insane with political ambitions and greed” – seemed a familiar ploy to stall Western action. But by closing his border to all goods save medicine and food, and cutting off phone lines and radio and TV broadcasts, say U.S. officials, Milosevic means business this time. “They are completely isolated,” says a senior administration official. “The pressure is building where it should, on the Bosnian Serbs. The airstrike is another sign that it’s over for them.”

It’s not over – yet. Even if the Bosnian Serbs settle, enforcing the peace won’t be easy. The place to start: resolving the tangle of U.N.-NATO operational conflicts.