The bombing of a UN building filled with humanitarian supplies is not the way to rebuild international support for the United States or Israeli actions in the Arab world or elsewhere.  Israel's activity is one thing--United States support or approval quite another thing altogether.  To the extent the United States supports Israel's activities when they do things like this, I have to believe that our interests suffer. The hatred that this and the Lebanon war have spawned will last several generations.  And the people that have been bombed will begin to turn their hatred towards the United States.  (Indeed, the effect of this act would appear to me to be isolating--see abstention in the UN Security council).  

Second, Israel's right to self-defense notwithstanding, when this is over, there will be no one left for Israel  to negotiate with--just a shell-shocked, abjectly impoverished, and angry population. War-making on this scale only makes sense (to me, anyway) if the objective is to solidify and extend territorial gains made over the years. Perhaps that was the point all along.   That may be in Israel's best interests--I have no idea, but my "gut" tells me that it will be counter-productive.