Thanks for the article. I also tend towards the view that Russia's involvement in the late stages of the war was the main factor leading to Japan's surrender, but we'll probably never know for sure. I didn't read the article in detail (sorry!), but one part struck me: 'but the nuclear strike fell precisely on two peaceful cities, which, as it turns out now (but requires unconditional confirmation), were the centers of Japanese Christian communities!'
The fact that these were centres of Christianity was widely known even before the war (though I imagine that Christians had to keep quiet about their beliefs during the pre-war era). Christianity certainly has a long history in Kyushu (see
Christianity in Japan - Wikipedia). You could perhaps reword the sentence as 'but the nuclear strike fell precisely on two peaceful cities that happened to be centers of Japanese Christian communities!'