remote-controlled weapons systems would be effective - a few rounds expended would quell the most ardent “asylum” seeker.
ROE - free fire zone.
Of course we want - need - an effective wall, else why bother?
If we have the patrols, we don't actually need the wall except in certain high-volume crossing locations (i.e. San Diego/TJ or Mexicali/El Centro).
Without the patrols, the wall is just expensive decoration.