What's currently happening in Israel is not self defense no more than Bush's invasion of Iraq. Both are a depraved form of hubris that allows the more powerful party involved to perform the same acts that they denounce in others.
Israeli's targets have been very deliberately trapped behind walls, denied food and medicine. Like a buffalo hunt in modern day America? Except the buffalos are fed and watered before the brave hunters lean on the fence and shoot them dead. These brave hunters are after healthy prey. But when the object is extermination? Well, that model has been practiced any number of times.