That article relies on some half truths and supposition although its basic premises can't be dismissed out of hand. I've read a lot of material on the subject and the idea that the Japanese were going to surrender regardless of us dropping the bomb is pretty sketchy. In the end the only lives we were really concerned about were American, and if using the bomb helped save our troops from enduring an invasion of the Japanese mainland then it was going to be used at that point. Our firebomb attacks killed a lot more people. And the reason we started firebomb attacks was that high altitude precision bombing over Japan was shown to be ineffective, after making the B-29 our largest wartime project (more expensive than the A Bomb) and we needed to use them for something.
It's possible that the Russians entering the fight might have eventually caused the military to reconsider their policy of no surrender, but that was out of our control - using the bomb was in our control, and it also showed the Soviets that the West was going to be the power in charge post war, not them.