On Sunday, January 13, 2019 at 11:12:14 AM UTC-8, amdx wrote:

I think a 20 ft chain link fence, lay [concertina barbed wire]...
.. Boarder guards to keep watch for
anyone trying to use equipment to breach.

That's a huge manpower sink for a border that hasn't been a military
problem since Pancho Villa rode. I'd propose a trial at the N Dakota/S Dakota border
first, to see if it stops invasion forces there.