To continue from the Water/Ag point earlier...
I live on the Colorado River in AZ. I would recommend you look up info on the pipeline/canal across the Mohave desert built in the 70s/80s supplying water to, in fac, SO Cal itself and everything in it which proves that moving water across a desert/Texas type environment is not that complex a thing to do.
A simple canal can accommodate all the water needs of ag/farms along the border. That argument is a provable non-starter. We have done it for decades. One can’t say we can do it for millions of people in Cali and not in Texas. That just doesn’t work.
Israel doesn’t have 2,000 miles of border to secure, nor a Rio Grande marking the boundary between them and their hostile neighbors. It’s been a few months since I checked this out, but I think there are some places where Israel doesn’t have a fence due to natural barriers. BICBW