Hello!
I would like to know the opinions of r/AskHistorians on the subject, and see where the historians on Reddit stand.
Justified is not the word I would use, but yes, I do. An explanation of course is required.
It is completely wrong to view the atomic bombs either in modern terms or to view them outside of the context of the war. Simply put, at the time they were viewed primarily as just really, really effective bombs. Radiation itself wasn't well understood. The long term medical effects certainly weren't understood. And fallout and the like weren't even imagined. So we today tend to see them as extra heinous. But that was not the view at the time.
And what was going on at the time was already incredibly heinous. Combined, the bombings in Germany and Japan killed hundreds of thousands of civilians... perhaps as many as 1.2 million. And they contributed to the deaths of others due to exposure and malnutrition. The first thing we need to consider is that it wasn't a question of atomic bombs or no bombs. It was a question of atomic bombs or conventional bombing. Whether conventional bombing was justified is a different question entirely. Not using the atomic bombs wouldn't have saved lives; those lives would have just been taken in a fire-raid.
On top of the deaths from bombings, there were still many ongoing combat deaths. Japan was fighting in China and Manchuria, along with a lot of fighting happening in SE Asia, the Philippines, Indonesia, and more. Ending the war saved the lives of Japanese and Allied troops, as well as civilian lives in those areas. In addition the bombings the US was tightening the blockade around the home islands. Ports were mined. Everything that could be interdicted was sunk (either by sub or plane). And so the folks in Japan were already suffering from famine. The sooner the war ended, the sooner they could get food and medical supplies. And the US was planning the actual invasion of the Japanese islands themselves. Estimates vary. But by all estimates, it was going to be a very bloody campaign. By inducing the Japanese to surrender, those (likely million+) lives were saved.
And that is the key point. There is no question that the Japanese had lost the war. They had been mostly driven from their acquisitions. Their navy was wrecked. Their country was being systematically destroyed. But for reasons of pride, "face," and a hope for a slightly better settlement, they were absolutely willing to sacrifice a million or more of their own soldiers and civilians. Only the shock of having a city destroyed by a single bomber (plus the attack by the Soviets) gave the peace faction in the Japanese government enough power to force the others to allow a surrender.
I've read enough accounts, I am fully convinced that without something new and uniquely shocking, the war faction wouldn't have surrendered. And millions of Japanese would have died in bombings, from famine, and in combat. The army was training women on how to fight the Americans with bamboo spears. And they were serious about it. Even after the bombings, there was an attempted coup to prevent the emperor and the peace faction from sending the message of surrender.
The choices American planners had was to either: 1- Negotiate a peace and allow an antagonistic, expansionist regime to remain in place. 2- Continue the war conventionally and allow (and cause) the death of millions. Or 3- Drop atomic weapons and hope that would convince the Japanese into finally surrendering. Given those choices, it hard to imagine anyone choosing differently. It was a horrific choice, but there were no palatable options.
Always a heated topic. I have some follow up questions for those brave enough to answer.
I've heard it justified to prevent a bloody invasion of Japan. Why invade? It's an island that could be embargoed, no?
I've heard we dropped the bomb on the day that the Soviets entered the war on Japan was a message to the Soviets. Any truth to this?
Some say that it was no worse than the fire bombing of Japan. Couldn't the fire bombing also be viewed as immoral?