Originally Posted by
Hempy
To be accurate, Roosevelt only asked for Soviet help against Japan at Yalta because he wasn't sure at that stage if the nukes would work. The Japanese knew they faced inihilation after Nagasaki proved to them Hiroshima wasn't a one off.
Stalin was a cagey f
er. He grabbed as much as he could while it was there for the pickings (Sakhalin etc)
I think you'll find though that the claim
"that the Russian campaign in Manchuria was the reason that the Japanese surrendered" is a little myopic.
Agreed on that last point. The bolded point underscores how hard the war with the Japanese was. Even with them being pushed back, they were fighting hard. FDR was looking for a way to end the war as soon as he could, and bringing the boys home rather than having them die overseas. Truman followed through on that.