For Israel, then, peace with Egypt has been not only strategically but also psychologically essential. Israelis understand that the end of their conflict with the Arab world depends in large part on the durability of the peace with Egypt — for all its limitations, it is the only successful model of a land-for-peace agreement…

Though Egypt failed to deliver the normalization in relations Israelis craved, the thousands of Israeli tourists who have filled the beaches of the Sinai coast experienced something of the promise of real peace. At least in one corner of the Arab Middle East, they felt welcomed. A demilitarized Sinai proved that Israel could forfeit strategic depth and still feel reasonably secure.

The Sinai boundary is the only one of Israel’s borders that hasn’t been fenced off. Israelis now worry that this fragile opening to the Arab world is about to close.