What would be the correct word for proportionality of a response? As in the balance between the offense and the retaliation (you are right in pointing out the meaning of it, which was indeed not what I meant, I'll excuse myself as being a non native english speaker ). Of course Israel has a right to defend itself, but at what point is the retaliation for attacks disproportionate? I think in that discussion you'd also need to consider effectiveness of the attacks, from both sides. Note that I don't know the answer, but at some point hundreds of civilian casualties vs a few makes you wonder if the scale of the response is appropriate or not. Out of the two major actors Hamas is (obviously) the worse one, because they specifically target civilians, but if the missile attacks are that ineffective, is it really worth this response, and aren't there better, less costly ways to counter? I honestly don't know enough about the whole thing to judge on that, so I won't, and it doesn't help that Hamas is using human shields/hiding their weapons in/near civilian targets.

edit: also blame the West Wing for having an episode called 'A proportional response'