5Oct2018 [laptop-built, view on narrow browser window]
In the American war with Japan, could an atomic demonstration-test have been effective?
After the July 16, 1945 Trinity test, there was a lot of discussion about how to use the atomic weapon in order to shorten the war with Japan. Some of the American atomic scientists advocated a demonstration shot in a non-populated, perhaps wooded area of Japan, in hopes that the Japanese Emperor and the Japanese military command would see they could not possibly defeat a country with such weapons.
General George C. Marshall and others, mainly in the US military, argued that due to a number of American assaults on Pacific Islands that produced high American casualty rates and extremely high (approaching 100%) Japanese casualty rates (death before surrender), not to mention the Bataan Death March, the atomic weapon should be used on Japanese cities because, in General Marshall's words: "We had to shock em.' General Marshall was concerned that a land invasion of Japan might cost the lives of upwards of 300,000 or more American army soldiers.
Another problem was that developing an atomic weapon had cost a lot of money, and it might be difficult for President Truman to explain to Congress why he financed a weapon he ended up not using.
Part of the reason for choosing Hiroshima was the primary target for that day was covered by clouds. Another reason was that Hiroshima had industrial plants that were making war-materials. However, it would seem that attacking a Japanese city's war production facilities might not be nearly as important as convincing the Japanese Emperor and his military of the hopelessness of trying to fight any country armed with atomic weapons.
It was not the population of Japan that was in charge of prosecuting the war, it was the Japanese leadership. To attack a Japanese city's war-making facilities and its population in hopes of convincing the Japanese leadership seems an oblique tactic.
Was it a deep cultural misunderstanding? Since the ratification of the Constitution after the Federal Convention at Philadelphia in 1787, the American gov't has been extremely well acquainted with Americans petitioning the gov't for change. This happens all the time in America, especially in the House of Representatives. The American gov't may have assumed that combining targeting war-making facilities and the population of Japan would have convinced the Japanese leadership to surrender. It's not clear why the U.S. gov't would have made such an assumption.
In 1945 the Japanese Government was anything but a representative gov't, it was radically different from American representative gov't. To promptly convince the 1945 Japanese gov't to change a policy may have required addressing the gov't directly. To try and convince the Japanese gov't by destroying war-making facilities and Japanese cities sort of seems to be the long way around.
Futhermore, the Japanese leadership might legitimately feel that the destruction of Hiroshima was a test of their actual strength and fitness to lead the country. They might legitimately feel that if after Hiroshima they had surrendered it might make them look weak and unfit to rule the country.
Hiroshima might easily have had been taken as a challenge to their leadership, thus creating the opposite effect and strengthening the Japanese military's resolve. And after Hiroshima was destroyed, that may be how the Japanese military leadership felt (at least until the Nagasaki detonation).
"When news of the Nagasaki bombing came on August 9, the Supreme War Direction Council reacted not by moving toward peace but by declaring martial law throughout Japan. With the cabinet unable to reach a consensus on whether to accept the surrender terms, and War Minister Korechika Anami leading the opposition, its members finally turned to the emperor for a decision."
Yet another problem with targeting Hiroshima is that at a distance of 675 kilometers, the city was vastly too far away from the Japanese capitol for the Emperor and the military to readily appreciate the immense scale of damage such a weapon could do in the war against Japan. After the Hiroshima detonation, it's possible the Japanese military leadership wondered that if the atomic weapon was such a persuasive new weapon, why it was used on such a distant target.
Nagasaki is almost 1,000 kilometers from Tokyo, one of the furthest major cities from the capitol of Japan. For addressing the Japanese gov't directly, it would seem to be hard to pick a worse area to target.
A different strategy might have been to inform the Japanese leadership well in advance of a demonstration shot, far enough away from their physical location that they would not be harmed, but definitely close enough that they could see the fireball and the plume going up 30,000 feet high. It's not easy to think of a single reason to use the atomic weapon at distances so extreme it risks the isolated Japanese leadership telling themselves maybe it wasn't as effective as it really was.
In 1946 the U.S. Gov't assembled many thousands of US servicemen at the Bikini Island Pacific test site for a close-up demonstration of the destructive power of the Baker Shot for Operation Crossroads. Obviously, part of the reason was because American gov't and military officials as eye-witnesses could form a far more accurate and dramatic impression of the actual scale of atomic destructiveness.
The suggestion made here is that the Japanese military command might have needed the exact same eye-witness lesson. So in like manner to the many U.S. Military officials and thousands of US servicemen witnessing a close-up demonstration of the destructive power of the Baker Shot, it would seem not insuperably difficult to make one or more atomic demonstration tests that were at least within visual distance for the Japanese military command to witness. It would give them the same opportunity to try and realize the vast scale of instantaneous destruction.
Some atomic scientists suggested telling the Japanese gov't in advance to evacuate a specific city as it was going to be the target of a demonstration shot. If the Japanese people had got word of the sheer scale of the atomic demonstration test for the Japanese military, they may have needed very little additional prodding to evacuate.
It's important to remember the US atomic scientists themselves could scarcely believe the power of the American atomic demonstration. And the atomic scientists at Los Alamos had years to theorize about it before seeing it. It doesn't seem unreasonable to suggest the Japanese military may have also had serious doubts unless they had the same opportunity to personally eye-witness one or more atomic demonstration tests.