@dlowan,
--A lot more stress should be put on money laundering (in both sides, it is calculated that 70% of the profits stay in the US), with specialized intelligence work (now most of the laundered money discovered is by serendipity). The problem, in both countries, is that fighting money laundering means stepping into business interests (mostly in the financial and real state sectors).
--There should be more of a follow-up about weapons. I mean, a Mexican without documents in the US ("an illegal alien") has trouble getting a driver's license, but can readily buy hand granades. Any weapons taken from the cartels should be easier to track... and whoever sold them to the criminals should be punished.
--Mariguana should be decriminalized in both countries. It accounts to nearly 60% of the business, and is less harmful than the other drugs.
--There is a good iniciative in Mexico's Congress now, about a unified police. Most (sadly, not all) of the police-cartels corruption is at municipal ("county") level. According to that strategy, all municipal police will be monitored, and only those corporations who "pass the test" will remain. The others will be dismantled, and the unified (state under the surveillance of the Federation) police will take over.
All this said, those measures will not end the mafias. They would keep on traficking with the drugs that remain illegal, and may turn into other illegal businesses, specially extortion and person traficking. But they would certainly hinder their performance.