we need razor wire now
while we build the wall
Electrified razor wire, behind a trench loaded with IEDs!
Moats with gators n snakes, piranhas ifn we can get em.
Single strand Concertina would be ineffective. I've breached that in a prowl and growl training situation patrol. I got all the way into and all the way out of my objective without detection. The only patrol of the brigade sized exercise to lay claim to that.
But triple strand with both engineer stakes and tangle-foot wrapped around stakes at ankle height in a complex pattern for about 75-100 meters standoff from the razor wire then covered with sensors or better yet, trip flares to give an alert for a patrol to probe the disturbance.
They should have ROE that is appropriate to an invasion force especially where elements of the Mexican Army may be providing an armed escort as they have on over 200 previous occasions since GW was POTUS. The Mex Army or possibly their SOF units called the Zetas act as screen for the drug cartel smuggling ops. Prior ROE called for Border Patrol to "Run and Hide."