Mexico and drug law

The New York Times offered five people (such as Jorge Castañeda) the opportunity to comment on the recent changes in Mexico regarding decriminalization of small amounts of drugs. Once you winnow out the platitudes, the responses seem to converge on certain issues:

First, the law will have little or no impact on the broader drug war or violence.

Second, it may have an impact on reducing police corruption, which usually required a bribe to avoid being hauled in for possession.

Third, it will not lure more Americans to Mexico to take drugs.

What the authors were not asked to do, and should have been, was to discuss whether the reforms taking place in Mexico and Argentina mark a real shift in thinking across Latin America, or will likely remain isolated cases. If the former, then eventually it could (could, not would) influence policy making in the United States. Tony Payan (from UTEP) mentions the issue briefly, but it would have been interesting to probe in more detail.