First, relevance. Time alters history to the politically correct side of an equation. Be it EVs or A-bombs.
Nice. Way to go.
So all those innocent victims are just 'casualties'.
Back then we had the technology to spot bomb targets? What about all the film of this being done?
And Japan was ready to surrender, before these horrible actions....
OK, so why a second one so soon?
Dang it why does this 'extra credit' have to creep into The Highest Tech Car Forum?
It was in some reading that I was doing that day, and it surprised me that out of all the WWII coverage in books and film, this is not mentioned.
The whole idea of the Yamato-class was that you could win a war with fewer, more technologically advanced weapons. The Yamato was the most advanced battleship design ever and the pride of Japan. It showed the Japanese public that the Japanese military is superior to other nations, even the USA and Britain. Since Japan is an island, naval power is the supreme weaponry at least in the minds of the Japanese people and military commanders.
The idea was that the Yamato and it's sister ships could defeat a much larger force of lesser capital ships, especially if they knocked out US capital ship fleet first. Admiral Yamamoto knew it was a bad strategy, and warned both the generals in private and Japanese public in the newspaper, that this was likely to be a serious mistake. But he was overruled.
Obviously come the Battle of Midway, Yamamoto was proven correct, where the Yamato proved useless to deploy into the battle, and that was the beginning of the end of the Pacific war with Japan.
Why did the US drop a second bomb?
While the final decision rested with the President, the military advised to use everything we had, which only amounted to 2 weapons of different designs. Only one design was even tested, and it was not a radar triggered field test either. It was more like a lab experiment than a weapon test. The untested design was used on Hiroshima without knowing if it would even work at all.
Most likely the idea to was give the illusion that the US had a stockpile of these weapons and could destroy all of Japan from the sky. But there was also the consideration that atomic attacks involved only a few planes with most their defensive armament removed. When the Japanese military realized that a small group of planes were used for atomic attacks with no escort fighters, and slow airspeeds, they would focus their air defenses on these.
Were the Japanese ready to surrender?
The Japanese government was split concerning surrender after two atomic attacks and the decimation of Tokyo and many other cities. The Emperor broke the tie, but there was a coup attempt when he told the Generals about his decision to surrender but had not announced it publicly yet. The idea that the ground forces could not defend Japan from what President described to them after Hiroshima:
"It was to spare the Japanese people from utter destruction that the ultimatum of July 26 was issued at Potsdam, their leaders promptly rejected that ultimatum. If they do not now accept our terms they may expect a rain of ruin from the air, the like of which has never been seen on this earth." - President Truman.
Were the Japanese finished before Nagasaki?
The Japanese ability to wage a war of aggression in the Pacific Ocean ended June 20th, 1944. This is when they lost air superiority.
Japan knew they were going to lose the war by the time of Potsdam declaration on July 26, 1945. The question remained whether Japan should fight to the last man instead of a surrender. So they did not reply. It wasn't just the government who was notified. Millions of leaflets and radio broadcasts in both Japanese and English were spread across the population centers.
Hindsight is always 20-20 vision so nobody knows what would have happened if only one atomic bomb exploded. Since Japan destroyed over 90% of their war documentation, there are huge gaps in written or recorded history, all we are left with is what was verbally said by people who could have be convicted of war crimes for their brutality to the Chinese, Koreans, Phillipinos, POWs, etc, or held accountable by the Japanese people of dishonorable conduct.
(If by 'spot bombing' you mean precision bombing, it only existed in dive bombing or low altitude bombing. Nagasaki's bomb missed the target by nearly 2 miles which was common for high altitude bombing of the day.)