Tactically: The Security Fence does make it more difficult to perpetrate the horrific suicide bombings that plagued Israel these past few years. It doesn't make it impossible, but in the same way that the electronic fence along our border with Jordan made it much easier to prevent infiltration of terrorists from that country, so too the Security Fence contributes to the ability to thwart attacks in Israel proper from the Palestinian Authority controlled areas.
Strategically: I buy into the premise that the Arab population which live on the West Bank of the Jordan River are here because of the economic opportunities the Jewish settlements created over the past hundred fifty years. Just read Mark Twain's description of his visit to "Palestine" in "Innocents Abroad" to understand what existed before Jewish settlement reclaimed this land. (See Joan Peter's "From Time Immemorial" for over whelming detailed support for this thesis.)Depriving the residents of the Palestinian Authority the opportunity to work illegally in Israel, of the ability to smuggle contraband into Israel for sale and the opportunity to smuggle stolen goods from Israel to the PA for export to the Arab world ... in short, depriving them of the ability to leech off Israel's economy, will force them to create their own economy. Based upon the results the Palestinians have had from "inheriting" the hot houses of the Jews of Gush Katif, I'd say that without Israel there will be a gradual exodus of hungry people looking for a livelihood (and a 'life' away from the violent control of terror).
Without the "Security Fence" neither of these objectives are obtainable.
If saving Jewish lives and empowering future Jewish governments to minimize the Palestinian Authority's ability to leech an existence off the very entity they despise and aspire to destroy, means that I have to travel through a "Check Point" to enter the State of Israel - so be it. It is a minor price to pay.
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