Land mines would do a great job.
They wil have to hire gunslingers, just like in the old West. Plenty of army and Marine veterans to do the job for the right price.
Need to spread stories of all types...true or not... If the gringo american goes crazy on the border, they might hesitate to risk a crossing if “citizens gone rouge”....can’t hurt.
I agree, No one in their right mind would attempt to cross a mine-field... We should take down the fences & mine 800m on our side of the border.
Land mines don’t distinguish between ‘mules’ and cows, unfortunately...
Raising cattle in a mine field sounds like a great idea.
Deer and other game would also love it.