Good walls make good neighbors.
When your neighbor can’t seem to help himself from coming onto your property and stealing your stuff.
This will work.
I forgot to add this. If I were a Mexican National I sure as hell would try to enter this nation if it were a barbed wire fence in the desert.
It is hell in Mexico if you have no skills. The risk of dying in the desert is worth it. Actually if you want to survive the desert carry 1 gallon of water for each day. You really do not need food but if you do it should be high in sugars, fats and carbs. You can get your protein later. Bring water, a lot.
I would not cross a 300 meter mine field. I do not want to die.