Although stopping all is a worthy goal, stopping most is a win
I saw a three tiered razor wire structure. It looked pretty formadible. I prefer that to a real wall along the river in Texas. The wall moves the border.
A wall cedes the river to Mexico unless built on their side.
These obstacles are useless, unless: under observation and covered by fire. The fire does not need to be lethal fire, it could be fire hoses, tasers, sound, Active Defense Systems (ADS), etc.