Abbas won't agree to a final-status document that leaves Israel with ALL the settlement blocks. He will have to insist upon at least one big scalp so that he can sell the deal to his constituents. And that scalp will be Ariel, precisely because it is THE settlement block that makes no sense in terms of "Israel's security needs".
UN aid chief says no warring parties observed Yemen truce (Reuters)
from the article: The Big Mac Index of the delusion that 'Ariel is part of Israel'