Humanitarian law huh?
Gee not much said about all the Isreali's killed by Hamas and their rockets and suicide bombers. Guess that doesn't come under "humanitarian law."
Claiming moral outrage when violence is directed at you while attempting to absolve yourself of moral responsibility when your own side engages in atrocities is a losing argument because it's easily recognized as hypocritical. You simply can't have it both ways no matter how you try to convince yourself that you can. If the violence directed at you is immoral when it kills civilians, the violence you direct at the other side is also immoral when it kills civilians on the other side. Likewise, any claim you make to protecting yourself and fighting for a just cause can be made by the other side as well.
It's this fact that makes conservatives' argument to being "principled" such a joke as far as I'm concerned simply because they're ALWAYS trying to play both sides of the moral outrage fence; on the one hand, they're outraged at the violence directed at Israel, and on the other hand, they're outraged when anyone dares to suggest that Israel might actually be in the wrong when they engage in military operations which end up killing large numbers of civilians, including innocent women and children. That kind of simplistic sophistry doesn't impress me in the least, and I don't buy it any more than a lot of other people who see it for exactly what it is: total BS.