Israel is responsible first and foremost for the security of its people.
I agree, but that doesn't justify war crimes. Such crimes are, by their nature, not worth the military gain from engaging in them. They represent a gross neglect of human rights and a clear violation of international laws that Israel is a party to and has agreed to abide by. The road to hell is paved with good intentions. That's why we have created a common consensus concerning the rules of war and delineated what is and isn't acceptable. Israel has simply routinely engaged in military acts that are well within the realm of that which has been deemed unacceptable, barbaric, and inhumane.