You're...not sure what significance I assign to Hiroshima and Dresden having taken place a long time ago.
Very well, then; let me explain. When an event of international significance - like World War Two, let's say - is concluded, historians examine its conduct and implications for lessons learned, which typically form the basis for preventive action (assuming the overall experience was unpleasant and/or destructive, and repeating it is to be avoided) to ensure it does not happen again. The Holocaust; how about that? So committed was the world that nothing of its like should happen again that it inspired the simple two-word incantation, 'never again'.
Never again - in case the significance of that is likewise unclear - means such a lesson learned that its horrific disregard for human life must never be allowed to happen again.
Dresden and Hiroshima both happened a sufficient distance in the past that the wanton destruction of lives and property should serve as a lesson, not an inspiration. What that means, in simple terms, is that the joyous harvesting of the helpless Palestinians in Gaza is a sickening spectacle that has resulted in the Jewish people being hated as they never have been at any point in previous history...because Dresden and Hiroshima and the Warsaw Ghetto should have taught them better. And you, Mr. Rothschild, are not improving their assessment with cavalier bumper-sticker reasoning that Israel is killing civilians in Gaza because that's just what governments all over the world have to do to preserve their state.
What's Israel so crazy about? So 1,200 or so Israeli civilians were killed on October 7th - isn't the death of civilians just one of those things that happens in modern war? I'm sure it doesn't look so logical in that frame.
Going on what, 40,000 Palestinians killed now in reprisal? I'm afraid I'm not up on the latest score. The very great majority of them non-combatant civilians, even as Israel seeks to compound the death toll with starvation and disease and exposure. The part you don't seem to get is that it is one thing when civilians die in war, often because they were just in the wrong place at the wrong time. It is an entirely different kind of sickness to announce beforehand your intention to kill them all without sparing any, and to proceed on that course with the expectation you will not even be censured, but applauded, and to cover your cold-blooded soullessness with a lot of cockamamie chatter about tunnels and human shields.