>> all units we had a splash down. we had a plan is down in the river. >> they don't mind losing the truck into the river. at the end of the day if they can recover 2,000 pounds of narcotics with an estimated street value between 600 and 800,000 that's what they're going to do is protect that inventory. >> it's going under. suspect just about on my side. >> reporter: inside mexico, the army has visibly taken over much of the security in border towns. local mexican police who are not corrupted by the cartels are targets of them. thousands killed. and americans have been targets, too. >> you know, i almost think that we're flying over tribal pakistan, the way you describe this area. are you surprised or are you hardened to the fact that most of america doesn't realize this is going on? >> you know, it does amaze me, and maybe it's because i'm exposed to it so much working on the southwestern border, but we're in a war. we're in an engagement with an enemy that's like no other enemy we ever faced before. you have to combat these people with some of the same tactics that they employ on you.