TBP;
A fence is ridiculous! Any half-wit trained terrorist could repel right over it. A group of men could easily dig under it! Hurricanes would destroy the fence on almost a yearly basis.
That's why we electrify it, make it barbed wire, dig it deep into the ground (several feet), and put a (deep) moat behind it, followed by an increased, well-armed Border Patrol/National Guard.
And a fence is working for Israel. Have you noticed that suicide bombings in Israel have diminished to virtually zero since they built the thing?