As long as we're talking about Hiroshima and Nagasaki, it's worth pointing out that humanity's experience with the insidious effects of nuclear radiation had not yet been formed -- they began that day -- and that leaves the trade-off of "frying people with nukes" versus "shooting and/or exploding with regular bombs" look a lot more humane. (In either case assuming peace is not yet secured, obviously.)

Or we could light their cities on fire with bat bombs. War is hell.