A big wall, with unmanned automatic MG turrets that shoot and kill anything bigger than a Taco Bell chihuahua setting foot on this side of the river. I'm sure someone can come up with that if given a few billion dollars.
No we need manned placements the Rio Grande is a tourist spot and a lot of rafting goes on.
I prefer a fence patrolled by M1A1 and aircraft.
… with unmanned automatic MG turrets that shoot and kill anything bigger than a Taco Bell chihuahua …