This is a key point about why out-and-out legalization is necessary. Decriminalization of use and possession worsens the situation next door, worsening spill-over effects as well.
By refusing to acknowledge reality we will continue to shoot ourselves in the foot, in the process shooting our neighbors in more vital areas.
"Several U.S. states like California and Oregon have decriminalized marijuana, making possession of small quantities a misdemeanor, like a parking ticket. Decriminalization falls short of legalization because the sale and distribution remain a serious felony. One of the big reasons for the move is to reduce the problem of overcrowded and costly prisons. While this strategy may make sense domestically for the U.S., Mexican officials say it is the worst possible outcome for Mexico, because it guarantees demand for the drug by eliminating the risk that if you buy you go to jail. But it keeps the supply chain illegal, ensuring that organized crime will be the drug's supplier."
- Solutions to Mexico's Drug Crisis - WSJ.com (view on Google Sidewiki)