This is a crude fact that Sicario shows present-day drug wars beside the US-Mexico border.
For people who are watching this kind of movie for the first time, the side shown in Sicario is completely different. The movie shows not only the massive and difficult nature of the drug trade there, but it also shows the unusual means the good guys have to take to try and pull apart the trade.
After uncertain upon something which was risky during an operation in Chandler, Arizona where two FBI agents are killed, Macer (a Special Weapons and Tactics hotshot) agrees to join an elite team created by the Department of Defence