This article covers some very interesting developments, in South America. It seems that both the cartel violence and the missed revenue, as well as an understanding that marijuana is not the dastardly drug made out to be, are causing broad re-evaluations of the policy on the drug war. Countries may soon start leaving the Single Convention on Narcotic Drugs. Aside from common sense policy within those countries, how might this impact the foreign relations in the New World and pressure the US to change its policy? Here's for hoping for change! South America Sees Drug Path to Legalization
No doubt the US will start applying pressure to these upstart nations, perhaps even moving military closer by or making direct incursions to go after traffickers. As the police of the world, the US decides when something should be legal or not.
I really don't see that happening. The military, really? It's a political issue, and with parts of both Europe and South America altering the adherence to the Convention, the only thing I could see happening is a change in foreign aid. Now imagine if Mexico decided to go that way too, and legalized trafficking to reduce cartel violence...
The DEA is engaged in quasi-military operations all over South America and they operate with impunity.