How is the drug business affected by illegalization (that is, having to do normal business processes in secret and without public laws to enforce agreements/ contracts)? and, how does the drug business connect different sites within Mexico, and across the border?

How is the drug business affected by illegalization (that is, having to do normal business processes in secret and without public laws to enforce agreements/ contracts)? and, how does the drug business connect different sites within Mexico, and across the border?