March 27, 1999: it was the fourth night of Operation Allied Force, the NATO bombing campaign against Serbia. The effort's initial phase had gone remarkably well; U.S. and allied aircraft had inflicted heavy damaged on Serb air defenses and other critical targets, without the loss of a single NATO aircraft. When the Serbs tried to fight back, they generally paid a high price; three of their MiG-29 Fulcrums had been shot down in the early hours of the conflict, and a number of surface-to-air missile (SAM) batterys had been knocked out of action as well. But the Serbs would soon...