Jus ad bellum, Jus in bello

I came across an interesting article in a January issue of The Economist. Western Theory states the following: on the grounds on going to war, (jus ad bellum), the cause must be important enough to justify force: in other words the good that follows must outweigh the death, injuries, and destruction of said war. In the conduct of war, (jus in bello), any action must weigh the military gains against the harm to civilians. How can we measure this? In the Israeli-Palestinian context does this conflict begin in 1948 with the displacement of the Arab people of the Palestinian region and the subsequent occupation by Israel? I don't think Israel or the west will ever look at this issue in this way. If the crude rocket firing is the starting point then surely Israel has the right to defend its borders. But does the firing of rockets into Israel by Hamas warrant the barrage that followed? If so was it in line with jus in bello? Will there ever be a sit down with the leaders of Hamas, Fatah, and Israel? The killing of innocent people will continue until this age old dispute is settled. Remember, we are dealing with more than Hamas here..we are dealing with a systemically battered people here. Click on the title above for a Palestinian point of view. An Israeli point of view to follow...