re: citation.
The bar chart on page 2 has a black line on it. Look at it, assuming it doesn't somehow hypnotize you like a chicken.
The Taliban took over Afghanistan beginning in the middle 1990s. They, at least officially, banned opium growing in 1997. Note the trend after that. If your theory is correct, the trend in growth should have gone drastically downward over the following years, instead on one single-year dog and pony show to impress the international community. Note that they did not destroy the opium stockpiles at the same time. In fact, they were sold off at even higher prices.
Incidentally, it's not hard to shut down the drug trade if you can just arbitrarily kill or imprison the farmers, and burn their farms.