They were part of Jordan, which used them to launch their attack against Israel in 1967. Israel took control of the lands legitimately to secure their borders against further invasion and attack by a proven aggressor.
You can't give something "back" to someone who never had it in the first pace. If Israel "gave back" these lands, she would give them to Jordan.
Do you think that would advance the cause of a Palestinian state? If so, why didn't Jordan create a Palestinian state out of these lands when they had them the first time?
You see, you have sucked down the premise that what is Israel's is actually Palestine's just because some terrorists say so.
Quite shallow of you really, and stupid.
It goes on and on because one lie and one mistake after another creates more chaos. Jordan shouldn't have signed a separate peace and Sharon shouldn't have gone into Shatilla and Arafat shouldn't have counted on marrying an American to give him cover.
Give up the settlements, share Jerusalem, let the Palestine State be created ... and insist that Syria, Egypt, Jordan and the other Arab States guarantee that "Palestine" will be peaceful...or they get a chance to see a need for all new military hardward.
The fact that we can trust Israel and not the PLA makes it clear we have to force the PLA to behave...half-measures and "timely" withdrawal won't work.
Get out, tell them the consequences of attacks and let the Saudis foot the bill for reconstruction. Allow the Palestinians back into Jerusalem while the agree to share Bethlehem (and make it the Palestine Capitol) while reverting to Tel Aviv as Israel's Capitol. If they continue to play the thug then reoccupy, round 'em up and ship em off the Saudis...and start drilling in Anwar.