Illicit marijuana is America's number one cash crop with total annual sales of $32 billion. The states of Tennessee, West Virginia and Kentucky produce about 40% of that amount, with Kentucky contributing the most. Those three states report to having destroyed more than $11 billion worth of pot in the last decade.

On hot summer days in parts of Kentucky, the air reverberates with the sound of attack helicopters swooping onto pot fields that are carefully hidden under mountain forests. Highly disciplined troopers - men and women who are trained for combat - approach targets with an air of authority...