SDSU Aztec wrote:
Trump often cites Israel's wall as being proof that walls work. However, Israel's wall cost was $2M per mile compared to the $24M per mile to be spent from the $5.7B being requested by Trump. The current U.S. barriers cost $3.5M per mile. He needs to explain what the differences are and why it makes sense for the U.S. to spend so much more.
The problem for Trump with the Israeli West Bank Barrier is it is not a wall but rather a series of fences. Only 5 to 10% or the barrier is a concrete wall , the rest is fencing. The barrier is a "multi-layered fence system" with the IDF's preferred design having three fences, pyramid-shaped stacks of barbed wire on the two outer fences, a lighter-weight fence with intrusion detection equipment in the middle, an anti-vehicle ditch, patrol roads on both sides, and a smooth strip of sand for "intrusion tracking". The result is it is relatively cheap but has a large footprint and needs constant patrolling. The intrusion tracking strip of sand is groomed twice a day.
This is probably feasible for Israel as the border length is just a bit longer than the Arizona - Mexico border and they have committed a lot of manpower to controlling the West Bank, 10,000 troops alone. For the US to commit a similar effort to patrolling the southern border would require potentially quadrupling the current CBP staff allocated to that region, 16,605 in 2017.
https://en.wikipedia.org/wiki/Israeli_West_Bank_barrier#/media/File:West_Bank_Fence_South_Hebron.JPG