This is the dirty little secret of the Afghan war. When they were in power, the Taliban almost completely eradicated the opium trade. Since the U.S. government deposed them, Afghanistan has once again become the largest exporter of heroin in the world.
In rejecting the Russian request, U.S. officials stated that the "Afghan drug problem had to be handled carefully in an effort to avoid alienating local residents".
When was that ever a concern in Columbia or Mexico???