I got a lot of my info from my father, who was actually there for yrs. He knew a lot.
Your father had no information on Truman's decision to nuke two Japanese cities, nor did any other soldier or sailor serving in the Pacific, and your father had nothing to do with the decision. If Truman had done what he knew he needed to do to end the war in July, the overwhelming majority of GIs would not have cared one hoot that the emperor was not deposed.
There seems to be a heck of a lot of arm chair quarterbacks and Monday Morning 20/20 rear hindsighters on this thread.
Oh, no, no, that dog won't hunt. Truman KNEW that Japanese officials were sending out peace feelers in May, three months before Hiroshima. By early July, Truman KNEW that even the emperor wanted to surrender and that the only real obstacle was the fear that the emperor would be deposed. Acting Secretary of State Joseph Grew, one of the few genuine Japan experts in the government, gave Truman two extensive briefings in May and explained the emperor's status and limited power and why the Japanese would never surrender if they thought the emperor would be deposed. And Truman KNEW that Japan was already severely beaten and prostrate.
Truman lied to his own chief of staff and assured him that the nukes would only be used on military targets. He lied to the American people and told them the egregious falsehood that Hiroshima was "a military base" and that this "military base" was chosen as the first target to minimize civilian casualties. Truman was either being played as an absolute fool by the Japan haters in the War Department and the State Department, such as Byrnes and Acheson, or he was lying through his teeth.
And after Truman had nuked two Japanese cities and allowed the Soviets to enter the war, he proceeded to hand over China, northern Korea, and northern Vietnam to the Communists. In China, the Communists proceeded to kill over 30 million Chinese. We had to fight a bloody war just to prevent southern Korea from going Communist, and then we had to fight another war to try to keep southern Vietnam from going Communist, but Truman's fellow Democrats stabbed South Vietnam in the back and refused to provide the air and logistical support we had promised by treaty to give them.