Bobert,

According to UN Resolution 242 the line is the established Israeli border of pre-six-day war days, that is not going to happen, but it does provide the start point for any negotiation.

A DMZ must be enforced, patrolled and maintained, all at a cost I do not believe anyone would be prepared to take on. Even if someone were, it would in all probability be ineffective, so there is no real point in having one (case in point: the UN peace line, in effect a DMZ, did not work in Lebanon). If we are talking about a peaceful settlement then the foundation of that settlement is the realisation on both sides that they are better off living peacefully, better off co-existing. If that message gets hoisted home there is no requirement for a DMZ.