Interesting and apposite analogy. I think if I was attacked by someone with a 6 inch blade, in a restaurant, with my family present, I would do everything I could to defend myself and my family. This could extend to me grabbing a knife from the restaurant to do so, or using the attacker’s own knife on them if I was able to seize it from them. It might even extend to me killing my attacker in the act of defending myself and my family.
What I wouldn’t do, when the person who attacked me was plainly incapacitated, would be to go on to attack his family, including his children with the same weapon that I used on the attacker and everyone who happened to be sat near him for the next two hours.
Your first sentence only stands up to any form of scrutiny if it’s predicated on the basis that innocent children are as culpable as the monstrous and foolish people who launched the utterly misconceived strategic calamity that was 7/10; but that act of infamy (to borrow a phrase from FDR) however appalling, can never give Israel carte blanche, because if it does then deliberately starving children is acceptable - so unless you don’t believe that there has to be a line somewhere, then it’s obvious to anyone with any sense of reason and objectivity that Israel, from a position of legitimately defending itself, crossed that line some considerable time ago.
And the amount of firepower is far from irrelevant. It’s akin to saying that when that same person attacked me with the knife, and I happened to be carrying a machine gun, I’d be entirely justified to kill everyone in the restaurant with it, after I’d killed him, simply because I had it on my person. If every world leader thought like that then our species would already have wiped itself out in a nuclear Armageddon, and in turn destroyed the planet, many years ago.
The amount of firepower any nation possesses, and how it deploys it, is always relevant to any discussion about how it wages war, especially where an inequality of arms subsists. It’s inhuman to suggest otherwise.