NATO began the war over Kosovo with a one-volume Master Target File containing 169 targets. It ended with more than 976, filling six volumes.

"Producing" targets fell mainly to the U.S. Joint Analysis Center in Molesworth, England. There, U.S. intelligence was brought together, analyzed and transmitted over the classified Siprinet computer system to targeteers at the U.S. European Command. It also went to U.S. targeting cells in Vicenza and Aviano, Italy, where blue folders stuffed with maps, satellite photos and "aim points" made up a pilot's recipe for demolition.

Locating underground bunkers, storage sites, command posts and the like was only the first step in producing targets. Analysts then checked all sources of timely intelligence--satellite imagery, human sources, electronic intercepts of phone conversations--to make sure the buildings were still being used by the military as close to the scheduled strike as possible.

On orders from Gen. Wesley K. Clark, the supreme allied commander, the targeteers also had to work and rework the attack plan--the specific "aim point" of each missile, the angle of attack, the kind of weapon used--for any target where more than 20 civilians might be killed.

This time-consuming process threw targets back into the loop over and over again. By late April, NATO had more combat planes than it did targets to hit. Both Clark and the airmen putting together each day's tasking orders were frustrated.

To speed up the system, officers began 11 p.m. nightly sessions in which lawyers, targeteers and intelligence analysts--as many as nine participants at nine locations--joined in a kind of classified chat room on the Siprinet system.

By May, the group was churning out 25 targets a day, up from five a day at the start of the war.

Among the key participants were lawyers such as Lt. Col. Tony E. Montgomery, deputy staff judge advocate at the U.S. European Command, whose job was to ask: "What is the military value of this?" Over and over again, he referred to his softcover, dog-eared "Law of War," which he kept near the computer in his office.

Yet only once--in the case of an electronic plant in the Serbian town of Nis--did the group reject a target for lack of a sufficient military link.

After the internal military review, the target approval process passed through the White House, the British prime minister's office and the French presidential administration. During the first 45 days, Gen. Henry H. Shelton, chairman of the Joint Chiefs of Staff, was at the White House every day, seven days a week, with targets that needed the president's approval.

From Shelton's perspective, the White House process was expeditious, Clinton and his top advisers were quick to make decisions, and there was never a logjam of targets waiting to be approved. In the field, though, the wait sometimes seemed long and mystifying.