I'm Gonna Burn One Dow-ow-ow-own

The LA Times recently reported that marijuana is the largest cash crop in the US. Tom Riley, "a spokesman for the White House Office of National Drug Control Policy," said, "Coca is Colombia's largest cash crop and that hasn't worked out for them, and opium poppies are Afghanistan's largest crop, and that has worked out disastrously for them." He added, "I don't know why we would venture down that road."

I wonder if US-backed efforts to eradicate those crops in Colombia and Afghanistan had anything to do with how "that has worked out."