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 ask. >> you know, it does amaze me, and maybe it's because i'm exposed to it so much work okay 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 tact ticks that they employ on you. if you asked me ten years ago would we be doing some of the tactics and missions today, i would have said absolutely not. >> reporter: since 2004, the state department says 200 americans have been killed in mexico and nearly all caught up in the vicious firefights