Are you planning on fighting a shooting war with Mexico, or keeping people from illegally crossing?
The two are very different tasks. If you simply want to kill illegal aliens, it would work--but I guarantee you that such a plan would not survive being shown in action on ABC, NBC, CBS, CNN, and Fox News over morning breakfast.
You're sounding like one of the airpower evangelists who said that we could bomb Germany flat in WW2 and not have to send troops into Europe. Keep up.