That and to avoid commencing Operation Downfall, which would have been the mainland invasion of Japan. As one of the other respondents point out, the consequences of implementing this alternative versus the bomb would have been astronomically grave. The Japanese soldier fought tooth and nail, having no reputation for giving up easily; think how much all the more the Japanese soldier would fight with all his might when knowing that he was protecting the mainland of his country; implied within that scenario, the Japanese probably would've created a many of egregious war crimes against our men for the same reasons (though the Japanese committed a lot of terrible things against American soldiers); the Japanese population would probably have spiked to a high unprecedented in its history, as the Japanese people were taught that suicide is preferable to death to pretty much an obligatory degree; and, from our own end, dealing with such heavy ferocious fighting from the Japanese and consequentially harness such strong contempt for it that our soldiers, sailors, airmen, and Marines would commit a stewpot full of war crimes. Wherein history as we know it that over some 200,000 lives were lost, Operation Downfall would no doubt costs millions, especially if we were to take into account our allies--the British, the Australians, the Canadians, and the Soviets participating as well.

Despite my love for intellectuals and academics, I would like for someone to have made Anscombe aware of this (which she probably would already be aware of) and remind her that she is not the one neither planning this war nor fighting it.