NATO said it won a great victory, but the war did very little damage to Serb forces. By not conceding this, the Pentagon may mislead future presidents about the limits of U.S. power. A NEWSWEEK exclusive. It was acclaimed as the most successful air campaign ever. "A turning point in the history of warfare," wrote the noted military historian John Keegan, proof positive that "a war can be won by airpower alone." At a press conference last June, after Serbian strongman Slobodan Milosevic agreed to pull his Army from Kosovo at the end of a 78-day aerial bombardment that had...