Daniel Finkelstein hits the nail on the head today, as ever:

If Hamas, Fatah, Hezbollah, Iran and the surrounding Arab states decided that they weren't going to fight Israel any more, would accept its right to exist, and would agree to a Palestinian state formed out of the West Bank and Gaza, would Israel carry on fighting them? 

I think the answer to that is no.

But if Israel simply said it would release all the Palestinian prisoners, withdraw from the West Bank and Gaza, open all borders and lay down its arms, would Hamas, Fatah, Hezbollah and Iran leave Israel in peace?

I am pretty sure the answer to that is no, too.

And if Israel at least showed willing - made the offer of a Palestinian state, told the Palestinians they could have back the West Bank and Gaza, withdrew unilaterally from one of those areas as a firm gesture - wouldn't they then be able to win back liberal opinion?

After all, if the Palestinians and Hezbollah and Iran and so forth, still weren't satisified with that, and still went on fighting, then liberal opinion would turn back to Israel, surely?

Well no, again. And we know this because Israel did all these things, the Palestinians turned them down, and liberal opinion deserted Israel entirely.