Trust me, if the leadership saw this first hand it would make a much bigger impression.
Anyways, I think the conversation derailed a bit, I cannot claim this would’ve worked for sure, I don’t have a time machine. My point is, this was done with the intention to cause mass civilian casualties, which today one could argue it being a war crime (and that’s why I don’t approve of it), but of course, the Geneva convention didn’t exist yet at the time.
Maybe there was a different way to get the Japanese to surrender, with fewer casualties, but it doesn’t look like the US really tried.