Very powerful video story at PBS Frontline worth watching in its entirety: Opium Brides
It’s all about the collateral damage from drug wars and other wars. The government gets what it wants and the traffickers get what they want, and the poor farmers and their families get screwed.
Drug traffickers loan money to very poor farmers who use the money to plant opium crops. The government comes and eradicates the crops and the farmers are unable to pay their debt. Their daughters end up paying the price for the unpaid loan.
Note: many of the commenters at PBS seem to be unclear as to the reasons this problem exists, and could use a hand.