Joby Warrick, Washington Post, 26 Dec 08
An Afghan chieftain looked older than his 60-odd years,  and
his bearded face bore the creases of a man burdened with duties
as  tribal patriarch and husband to four younger women. His
visitor, a CIA  officer, saw an opportunity, and reached in his bag
for a small gift. Four  blue pills. Viagra. The officer returned four
days later to an enthusiastic  reception. The grinning chief offered
up a bonanza of information about  Taliban movements and
supply routes – followed by a request for more pills.  For US
intelligence officials, this is how some crucial battles  in
Afghanistan are fought and won.