Unless you expect the US to offer military aid or expect some kind of huge interventionist event which Mexico cannot even begin to afford, a big dumb wall will not do much good against established trafficking organizations. What do you think happened to the drug war and the wall? Where are the drugs now or how is that war going? This will go the way of the drug war. Illegals will get in. It will solve no problems and make already powerful existing criminal organizations become more clever. The US seems unprepared to offer any more support to mexico besides "fuck off build our wall". Criminal organizations fueled by our drug consumption are pretty much as powerful as the mexican military, and are even interwoven into it in corruption. A wall is a dumb bandaid for deeper problems related to american corporate labor desires, mexicans' desire to have a better life, american's desire to do all drugs, and the desire of all parties involved to profit, including the US.

So with all of those complexities I don't understand how a simple physical barrier will be a solution to much deeper problems.