On the one hand, I understand that smuggling from Sinai into Gaza has been a big issue between Egypt and Israel; and the Egyptian government is no friend of the Hamas regime now in Gaza, since they are the Muslim Brotherhood of Egypt in their genealogy and genesis. Some kind of barrier has been inevitable, and it's not entirely clear that this is a major departure from what already existed.
On the other hand:
That sends the frozen-ground-swell under it
I know there is no easy answer here outside of a peace settlement. I want Jerusalem to be the capital of two states, but I don't want the return of the Mandelbaum Gate. One Jerusalem for two peoples (three if we count the Armenians), three religions, two states, and the world. That may be the heavenly Jerusalem and may be unachievable. (Though I recall someone once noting that the ideal Jerusalem would have a three-day work week, since you'd get Thursday off for the Druze, Friday for the Muslims, Saturday for the Jews and Sunday for the Christians.)
I'd like to tear down all these walls. If you'd asked me if the Berlin Wall would fall in my lifetime I'd have said no (until 20 years ago, of course). I hope the separation wall falls, the Rafah wall falls, and everything that cuts people off from each other falls.
But it's Christmas and I'm being altruistic. I imagine myself as Ronald Reagan (and believe me, I've never done that before, except possibly during Pride of the Yankees) saying, "Mister Netanyahu, Mister Mubarak, tear down these walls!"