That's an odd point of view. With Operation Downfall, the Americans were planning literal genocide against the Japanese. If they hadn't surrendered after the atomic bombs, the projections were as high as 5-10 MILLION Japanese casualties (with several hundred thousand on the Allied side), precisely because Japanese policy had been to arm the citizenry with rakes and hoes if it came to that - i.e., the Japanese refusal to surrender despite there being no possible path to victory was going to cost the lives of many millions of their citizens. And America had little choice but to pursue that.
That America was willing to do this, if the bombs didn't work, seems to contradict your claim. (And I think the Americans had little choice to do so.)
I fully agree that America was very willing to commit atrocities, especially using atomic bombs (obviously) and firebombing civilian centers.
The key difference is that the US recognized that Japan could surrender, accepted that surrender, and instituted regime change with a goal of democratic prosperity.
I’m not convinced Israel would do the same. They certainly haven’t said anything about actual regime change and setting up a legitimate government.
> Operation Downfall, the Americans were planning literal genocide against the Japanese.
If you're at war and your opponent has lost but is foreign to the idea of surrender and fights to the last man, and you oblige him, you are pursuing war not genocide.
That America was willing to do this, if the bombs didn't work, seems to contradict your claim. (And I think the Americans had little choice to do so.)