Allegations of corruption, rampant human rights violations and civilian deaths are remarkably similar to the current situation in Colombia. As Peruvian coca production has gone down, Colombian coca production and domestic methamphetamine production have both gone up, along with the incarceration rate in the United States, now the highest in the world. This is not to say that all drugs should be legalized. Taxing and regulating marijuana would effectively undermine the black market.
Marijuana currently provides the black market contacts who introduce users to drugs like cocaine.
Current drug policy is a gateway policy. Separating the hard and soft drug markets and establishing strict age controls is critical. Right now kids have an easier time buying pot than beer. Drug policy reform might send the wrong message to children. But I would like to think that children are more important than the message.