The Mushroom Cloud Romance

According to researcher, Ward Wilson (senior fellow at the British American Security Information Council), the Japanese surrender in 1945 had virtually nothing to do with Hiroshima and Nagasaki and everything to do with the fact that the Soviet Union had just declared war on Japan and were rapidly preparing for an invasion (they had already invaded Manchuria and several islands to the north of Japan).........................................................................................And the fellow makes a very persuasive case. a) The timing is much more proximate to the Soviet actions (a full 72 hours had passed since Hiroshima and it wasn't until the Soviet invasion of Manchuria that the Japanese council finally met). b) The U.S. had already destroyed over six dozen Japanese cities via conventional methods and so what was one more, really? And c) the Soviet declaration and invasion represented a much more strategic change in the course of the war and it is that which generally moves the needle and not a change in the method of carnage....I mean, I know that the U.S. has this visceral (not to mention, perverse) hubris that it was us who won the war in the Pacific (through our ingenuity, technology, etc.) and that the other countries were simply along for the ride but maybe this is a myth as well.