That's just a convenient argument made by Americans to justify their military bravado. Saving 15 million lives by using Atomic bombs is a wierdly exaggerated statement. We are hearing this age old argument of aggressors justifying killing with the saving of lives relative to what would have been lost had the killing not taken place.
If the US wanted to end the war with minimum casualties, they could have done it by demonstrating a low yield atomic bomb's capability at a relatively uninhibited area.
Let me put it to you this way...
For most people, a gun shot to a leg will compel them to surrender and submit to demands made of them. Some people are tougher, they may need two gun shots before they submit. Take special forces training, for example. There are gradual escalation in terms of physical hardships to induce candidates to surrender and remove themselves from the roster. The US learned that cold temperature and being constantly wet are great motivators for lesser candidates to drop. No need to be sadistic like the Russians that everyone falsely admire.
No different in warfare. Although the first punch should be powerful enough to shock the enemy into confusion and hopefully submission, there are always more powerful reserves readied to be used in the event he refuses to submit. You presents the arguments as to why A, B, and C reasons should be compelling for him to surrender, then you present D, E, and F reasons why that if he refuses to surrender, more death and destruction can be rained upon his forces and his land. And so the escalation.
Japan received many shocking blows during the war. Her military were in tatters. The Army troops were initially slowly isolated, then swiftly isolated from their supplies. The Navy were rendered impotent to counter the Americans' and allies' navies. In the air war, her combat experienced pilots were being killed off daily, and had to resort to training boys in suicide missions -- the Kamikazes. Her cities received no protections from daily bombardment. The fire bombings produced hundreds of thousands of casualties, the word 'casualties' includes killed and wounded. The escalation from the Allies was inevitable and inexorable.
But Japan refused to surrender.
So what make you think -- naively -- that Imperial Japan would be so frightened at a low yield nuclear demonstration destruction of a small island somewhere witnessed by only a select few VIPs from both sides ?
OPERATION KETSU-GO
The sooner the Americans come, the better...One hundred million die proudly.
- Japanese slogan in the summer of 1945.
Japan was finished as a warmaking nation, in spite of its four million men still under arms. But...Japan was not going to quit. Despite the fact that she was militarily finished, Japan's leaders were going to fight right on. To not lose "face" was more important than hundreds and hundreds of thousands of lives. And the people concurred, in silence, without protest. To continue was no longer a question of Japanese military thinking, it was an aspect of Japanese culture and psychology.
- James Jones, WWII
Japanese Homeland Defense Strategy
With the greater part of Japan's troop strength overseas and industrial production suffering under constant American air attacks, the defense of the Japanese home islands presented an enormous challenge to the Japanese Imperial General Headquarters (IGHQ). On 8 April 1945, the Imperial General Headquarters issued orders, to be effective 15 April, activating the First and Second General Armies.
(1) These two Armies would be responsible for the ground defense of the Japanese home islands. Also, on 8 April 1945, IGHQ issued an order activating the Air General Army, effective 15 April. The purpose of the new Air General Army was to coordinate the air defense of Japan, providing a single headquarters through which cooperation with the ground forces and the Navy could be expedited in implementing the defense of the home islands.
(2) Simultaneously with the activation of the First and Second General Armies and the Air General Army, IGHQ issued orders for the implementation of
Ketsu-Go(Decisive) Operation. Defensive in nature, the operation divided the Japanese home territory into seven zones from which to fight the final decisive battles of the Japanese empire.
(3)
The strategy for
Ketsu-Go was outlined in an 8 April 1945 Army Directive.
(4) It stated that the Imperial Army would endeavor to crush the Americans while the invasion force was
still at sea. They planned to deliver a decisive blow against the American naval force by initially destroying as many carriers as possible, utilizing the special attack forces of the Air Force and Navy. When the amphibious force approached within range of the homeland airbases, the entire air combat strength would be employed in continual night and day assaults against these ships. In conducting the air operations, the emphasis would be on the disruption of the American landing plans.
The principal targets were to be the troop and equipment transports. Those American forces which succeeded in landing would be swiftly attacked by the Imperial Army in order to seek the decisive victory. The principal objective of the land operation was the destruction of the American landing force
on the beach.
The Quantung Army was defeated on mainland China, as so many have so often pointed out. But no sane military mind would dismiss the combat experience of the soldiers. The Quantung Army was on the march home and with its combat experience, the urban guerrilla warfare these soldiers could conduct against the occupying forces would cost inestimable lives on both sides.
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By the time of the decision to use nuclear weapons on Imperial Japan, fighters, tanks, and rifles were already being manufactured in underground factories, manned by children and the elderly, and these factories survived the Allies' bombings on the surface. The Japanese were creative to use peanut oil as lubricant for machines, to either manufacture these weapons or in the weapons themselves.
So how much more deaths could be from both sides if these weapons, no matter how inferior they could be, were used in an insurgency war against the occupiers ?
Do you really think that you brought on any new arguments ?
Japan was indeed fighting a losing war which become clear after battle of Okinawa & other battles fought on Japanese Islands & Japanese imperial government are to be partially blamed for pushing Americans to make the deadly Nuclear attacks. But Americans were really adamant & were making unreasonable demands. They were not clearly diplomatic in their approach as they had been with west European powers.
I somewhere read that before Hiroshima attacks Emperor Hirohito was ready for a "conditional surrender" which the Americans never took seriously & when the Soviet Union suddenly declared war on Aug. 8, the day before the Nagasaki Atomic bomb was dropped,Emperor Hirohito put pressure on the military government to immediately surrender unconditionally. But the Americans never heeded it & dropped the bomb again. At least they could have stopped with Hiroshima & avoided the Nagasaki nuclear attacks
The US and allies were never under any obligations to accept a conditional surrender.
Any 'conditions' are essentially gestures of goodwill that can be legally used against the victor's side at unknown time. So the better option is to demand an unconditional surrender and use those gestures of goodwill as inducements for cooperation later.
So the privy council represented the more nationalist elements in Japan !
but considering there was a failed coup attempt even after the events in Hiroshima and Nagasaki to stop the unconditional surrender the emperor had some valid apprehensions about intervening that early !
I doubt he knew of the failed palace coup --
AFTER both cities were destroyed.
The fact that there was a coup attempt means that the decision to use nuclear weapons was, in an odd way, justifiable in hindsight. The coup, later known, revealed that the Japanese government was seriously divided with the final authority -- the Emperor -- favored unconditional surrender, and the military favored continuation of the war, even on home soil.
What if the coup succeeded ?
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Just like loony 9/11 conspiracy theories, leave the A-bombs on Japan issue alone long enough, and a naive fool will raise the same old arguments as something new and shockingly discovered.