I misread it as "Would anyone" instead of "Why would anyone".
> Not only completely weighted to one side, but consisting in its vast majority of civilians.
That's nothing new with atomic weapons. There was massive firebombing of Japanese cities prior to the nuclear attack.
From January 1944 until August 1945, the U.S. dropped 157,000 tons of bombs on Japanese cities, according to the U.S. Strategic Bombing Survey. It estimated that 333,000 people were killed, including the 80,000 killed in the Aug. 6 Hiroshima atomic bomb attack and 40,000 in Nagasaki three days later.[1]
That puts the loss of life from the atomic attacks at just over a third of the total loss of life from bombing. The question is how long would the Japanese have decided to prolong the war before losing (or winning, given some unforeseen circumstance) and would more or less people have died before that point. A show of overwhelming force, with the promise of more to come, can go a long way towards stopping hostilities very quickly.
> There has been no "war to end all wars", in spite of hopeful predictions. We haven't had WW3, but "one side being vastly superior" has not prevented the US from being engaged near constantly in various wars since after WW2.
Total loss of life in WW1 is estimated to be around 18 million people (11 million military, 7 million civilian).[2]
Total loss of life in WW2 is estimated to be between 50 million and 80 million.[3]
Any conflict since WW2 hsa been miniscule in comparison. Total casualties in Vietnam are estimated to be below 1.5 million over almost an entire decade.[4]
I would say that we are very lucky there hasn't been a WW3. It likely would have casualties in the hundreds of millions.
> It is indeed a very complex topic, but questioning the ethics of those involved in the development of atomic weapons, especially given all we know about the way it was done, is a completely reasonable stance.
I didn't take the original statement as much of a "question" of ethics, as an assumption that none of them could be expected to act ethically ("why would anyone expect them to behave 'ethically'" is the specific wording) because of the nature of the work. I think it's likely that some of them thought they were working for the greater good, and we cannot assume a failure of ethics in all cases.
1: http://www.japantimes.co.jp/news/2015/03/10/national/deadly-...
2: https://en.wikipedia.org/wiki/World_War_I_casualties