Before embarking upon today's brief ramble through the applications of physics, I should confess to a small but significant personal bias. I am, in general, opposed to the blowing up of people with nuclear bombs, except where all of the alternatives have been exhausted; and even then only after the most careful consideration. On to business.
Oliver Kamm writes in today's Times a brief rant on the subject of this publication by the Campaign for Nuclear Disarmament; as you would imagine, he is against it. (Unaccountably he somehow forgot to link to the CND piece, but it is easy to find on their home page.) His complaint, so far as he has one, is this:
Conventional wisdom has it that the US dropped the nuclear bombs in order to minimise casualties, claiming that a ground war would have killed many more people. However, historical records have shown that Japan was in fact trying to surrender at the time. Dwight Eisenhower, commanding general of US forces in Europe in World War II and President of the US from 1953-1961, said, ``Japan was at that very moment seeking some way to surrender with minimum loss of face. It was not necessary to hit them with that awful thing.''
The Eisenhower quote is footnoted as a reference to Gar Alperovitz's Atomic Diplomacy: Hiroshima and Potsdam -- Kamm's `long-debunked thesis'. But Oliver, I think, is interpreting this as the citation for the whole paragraph, which continues,
The annihilation of Hiroshima and Nagasaki was a defining moment in global warfare and marked the emergence of the US as the world's dominant super power, a position secured by its unchallengeable nuclear might and its preparedness to wield it. This is the only time that nuclear weapons have been used in war.
Conventional wisdom has it that the US dropped the nuclear bombs in order to minimise casualties, claiming that a ground war would have killed many more people.
CND quotes Eisenhower on this point, but we can do better. From Richard Rhodes's (recommended) The Making of the Atomic Bomb we have, (pp 684--685)
US intelligence had intercepted and decoded messages passing between Tokyo and Moscow instructing Japanese ambassador Naotake Sato to attempt to interest the Soviets in mediating a Japanese surrender.
You can read some of the correspondence in translation at nuclearfiles.org (or in a library...). As Rhodes says, Sato was asked to interest the government of the USSR to mediate a negotiated peace; this wasn't really on, and Sato said so. The United States did not shift in its demand for ``unconditional'' surrender (i.e., surrender under the conditions in the Potsdam declaration -- roughly: occupation and withdrawal from the territories invaded by Japan; but the Emperor to keep his throne), but it is certainly true that Japan had a go at surrendering on its own terms in July 1945 -- before Truman made the final order to use the bomb (on the 24th, according to Rhodes).
Dwight Eisenhower, commanding general of US forces in Europe in World War II and President of the US from 1953-1961,
said, ``Japan was at that very moment seeking some way to surrender with minimum loss of face. It was not necessary to hit them with that awful thing.''
[CND's] treatment of the subject consists in denouncing as a lie the notion that the US dropped the nuclear bombs in order to minimise casualties, claiming that a ground war would have killed many more people.
The reference to `lies' is in the heading above the paragraph quoted: ``Dispelling the lies''. The CND author doesn't state their thesis explicitly, but it's clear enough by implication: a settlement with Japan could, they claim, have been achieved by accepting a negotiated surrender -- which Japan made some effort to offer -- with the result that fewer people would have been killed than would have been killed in the atomic bombings.
Now, there are solid reasons to think that that's not a very plausible counterfactual. But Oliver (`excluded middle'?) Kamm doesn't address them. Instead he shoots off on a tangent, quoting a US Army study on the likely number of casualties which the US would have suffered in an invasion of Japan (very large, not surprisingly). This isn't germane to the point; the thesis in the CND document is that both the bombings and a ground invasion could have been avoided.
In 1998, the Japanese historian Sadao Asada demonstrated, after assessing newly released documents about the surrender, that the dropping of both bombs was crucial in strengthening the position of those within the Japanese Government who wished to sue for peace.
Of course, if you want to address the question of why a negotiated surrender before the bombings was pretty unlikely to interest the Allies, you get into the (interesting but difficult) question of whether the bombs should have been dropped at all. Instead Oliver signs off with,