Or, as the WaPo puts it in this piece, "pharmaceutical enhancements for aging patriarchs with slumping libidos." Here's how it works--that is, for collecting intelligence, not biochemically:

The 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 into his bag for a small gift.

Four blue pills. Viagra.

"Take one of these. You'll love it," the officer said. Compliments of Uncle Sam.

The enticement worked. The officer, who described the encounter, 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.

According to the Post, Viagra has tactical advantages over more traditional inducements:

The usual bribes of choice -- cash and weapons -- aren't always the best options, Afghanistan veterans say. Guns too often fall into the wrong hands, they say, and showy gifts such as money, jewelry and cars tend to draw unwanted attention.

"If you give an asset $1,000, he'll go out and buy the shiniest junk he can find, and it will be apparent that he has suddenly come into a lot of money from someone," said Jamie Smith, a veteran of CIA covert operations in Afghanistan and now chief executive of SCG International, a private security and intelligence company. "Even if he doesn't get killed, he becomes ineffective as an informant because everyone knows where he got it."

The key, Smith said, is to find a way to meet the informant's personal needs in a way that keeps him firmly on your side but leaves little or no visible trace.

"You're trying to bridge a gap between people living in the 18th century and people coming in from the 21st century," Smith said, "so you look for those common things in the form of material aid that motivate people everywhere." ...

Afghan tribal leaders often had four wives -- the maximum number allowed by the Koran -- and aging village patriarchs were easily sold on the utility of a pill that could "put them back in an authoritative position," the official said.

I shudder to think what the pharmaceutical lobby will do with a national security rationale in its back pocket.

--Noam Scheiber