It sounds like the Reds already had an agreement with Truman to invade, but I wonder if they stepped up that time-table once they saw the first bomb go off. Perhaps they had wanted to wait (to avoid more costly war), but then saw the opportunity to get involved at the last moment and gain territory with little risk or loss?
Seeing the Norwegian underground attack on the heavy water plant. My dad’s cousin was in the Norwegian Underground. My dad asked him what he had done once (would have been in the late 70’s).
“Yes I was in the underground. Nobody, not even my family, knows what I did and I will die with those secrets. The NAZI’s are still out there.”
Whenever I read these types of stories I always think of him. He hid in a pile of coal in the basement when the Germans came through his house. He must have been 18 or so at the time.
He ended up being a very successful businessman.
If my memory serves, Stalin promised Truman that the Soviets would to go to war against Japan in three months, and they invaded Manchuria in exactly three months, to the day.
I recall reading one time that the agreement was for 90 days after the end of the war in Europe.