U.S. international drug fighting strategy as it has evolved in recent years comprises two related but distinct imperatives. The primary imperative is simply to limit the availability of illicit drugs in U.S. markets. Latin America has been the venue for most source-control efforts—especially the Andean countries, which supply 100 percent of the cocaine and (now) as much as 60 percent of the heroin consumed in U.S. markets. Standard supply-reduction measures include eradicating coca and opium poppy fields (sometimes spraying these crops with chemical defoliants), destroying processing laboratories and seizing illegal drug shipments en route to the United States. For instance, much of the $1.3 billion U.S. package of assistance to Plan Colombia authorized in 2000 was earmarked for supply-reduction purposes: mainly helicopters, planes and training to support a massive coca-spraying effort in Southern Colombia, as well as electronic surveillance technology to help detect the “northward flow” of drugs from coca-growing areas of that country.