Ariel Sharon, who has faced vociferous opposition from the right on this reasons that the move will shorten Israel's lines of defense from a political standpoint. That's arguable as as long as Israel exists its enemies will claim that it illegally occupies Palestinian land.
Ed Morrisey, the Captain, floats a different view:
But opponents of the pullout never seem to ask the next question: so Gaza is taken over by Hamas, which launches an attack on Israel... and then what happens?
What happens, I predict, is that Israel -- which would no longer have to fear mass murder of the settler-hostages in enemy territory -- will respond to Hamas as they responded to all cross-national attacks on Israel, most particularly in 1948, 1967, and 1973: with a full military response from the IDF, including air support, which they have rarely used in the territories since capturing them during the Six-Day War (after Gaza and the West Bank were used as staging areas for an Arab invasion of Israel).
Right now, Israel's hands are tied in the occupied territories. Israel is an occupying nation, so it cannot go all-out in combat within the territories without violating the rules of civilized warfare. Because Israel is in fact a civilized, Western country, it takes those rules seriously, even when the enemy does not. This is immensely frustrating, of course, since the Palestinian terrorists don't even recognize the existence of any sort of rules of warfare, civilized or otherwise; they have no restraint upon their behavior whatsoever.
While the wisdom of the overall withdrawal may remain in question I think the Captain has got this one bang on.
I would also point to Sharon's record and desire to create a strong secular yet Jewish state that will survive the test of time. He's a canny desert fox who has not lost his faculties - I don't think he's doing this to appease or because he lacks the proper convictions. I would not also ignore the real threat that Israel could take over once again if Gaza becomes a hotbed of violence.
It will, in any case, be interesting to watch.