A question for Sandwich (and I mean this as an honest question, because I'm not following Israel's domestic politics myself): did any politician ever consider trying to be the good guys? Sending aid to Palestine, instead of live ammunition? Would the idea have any chance of catching on?
I'm not Sandwich, but let me answer anyways.
It's got no chance. First, Israel is after all surrounded by people who have vowed its destruction even if they're completely unable to cause it, and so long as either side keeps talking the ultimate hardline, there's very little room to negotiate. Second, Israeli's political landscape is badly skewed to the right-wing hawks.
The right-wing parties in Israel hold power out of proportion there for three reasons. One, everybody around them talks up war with Israel periodically and the nation has a history of having to defend its right to exist with force of arms. The second is self-inflicted, in identifying as a Jewish State they necessarily embrace a degree of conservationism that comes with religion. But these are fairly minor issues.
The real reason Israel is run by their version of Michele Bachmann most of the time, however, is because of the US. This is not, strictly speaking, a political choice anymore, as the machinery that makes it possible is mostly in private hands. We have, on one side, Judaism in the United States reacting quite reasonably to the fact that Israel is surrounded by people who have vowed its destruction and the destruction of their religion and ethnicity.
On the other side, we have a population of our own religious crazies, who while composing a small segment of the US population still manage to outnumber the population of the Israeli state because the US is kinda huge. These are people who are working off End Times Prophecy Checklists and other similar drivel and
want Israel and its neighbors to be antagonistic because that's on their list. Wars and the rumors of wars. They give money to people who seem likely to bring about their desired apocalypse or at least keep things bad so the apocalypse still looks possible.