"Need to"??? Seriously?!
One of the major guiding principles of international law - especially the Geneva Conventions (which, for the uninitiated, essentially boil down to "rules for when shit has already hit the fan and you do find yourself at war - for the non-psychopaths among us") is that violations by one party do not justify the same by another!
In other words: no, Israel does not NEED TO bomb civilians in Gaza any more than Hamas NEEDED TO kill entire families in Kfar Azza!
That is just utter bullshit! Nobody bloody NEEDS TO massacre civilians!
For the record: I think I probably, on deeply personal grounds, despiseHamas more than you do! I am not excusing them! At all! I might be an atheist - but if I were not, I would want their leadership in hell!
But also: yes, I DO hold Israel to a somewhat higher standard! Absolutely, I do! That will be because the state of Israel claims to be a liberal democracy. I actually happen to believe in the ideals of liberal democracy (whereas I would not be seen dead subscribing to those of Hamas). So, you BET I expect leaders that claim to be in my camp to suck less than ones I would not be seen dead with!