I believe President Truman thought he would have been impeached had he not dropped the bombs on Japan. But he also thought it was the right thing to do.
But Mr. Bartlett errs, I think, when he opines that Truman probably did not have to drop the nukes on Japan. There was just no way American intelligence could have known how Japan would have reacted to an invasion of the home islands. Most estimates of casualties that I have read over the years put American losses at more than a million men.
Dropping the bombs also kept the Soviet Union out of Japan.
See "Downfall" by Richard B. Frank. He uses Japanese archival material to show that the invasion of JUST the southern island would have been far bloodier than we predicted because they had moved two additional divisions that we didn't know about there. Overall, calculations I've seen were 1 million U.S. dead, minimum, to take Japan. Frank also shows there was NO---zip, zero, nada---consideration whatsoever of surrender by the Japanese prior to Aug. 6.
The idea that Truman had any alternative to dropping the atomic bombs is a revisionist myth. Casualties were higher in several conventional bombings throughout the war, and one only needs to review the horrific casualties at places like Iwo Jima to realize how catastrophic a full-scale invasion would have been for both sides. Hiroshima and Nagasaki probably ended up SAVING millions of lives.
I might agree on Hiroshima, but I think the Nagasaki bomb was just over kill.
The Japanese were ready for the invasion and the result would have been similar or worse than that in Okinawa--a complete fight to the death. Both the military and civilians were being prepared for the final battles and it would have been devastating for all. The bombs were needed and ended the war. That's the only thing Truman did to get my vote. His handling of the Korean war, however, was awful. It was the first of the RAT start-but-never-win wars. Now the MSM and the RATs are determined for us to lose yet another war. It's so depressing.
Fortunately, it worked.
The man is a fool. Our casualties from an invasion of the Home Islands of Japans would have been horrific. However, the atomic bomb saved more Japanese lives than American. We had total domination of the sky. We would have bombed Japan for months. Every major city would have been fire bombed with casualties that would have made Hiroshima and Nagasaki look like an afternoon tea party. The Japanese fought on Okinawa to the last man. They would do the same on the home islands. They would give no quarter nor would we. It would be a battle of extermination. Japan should be grateful that we dropped the bomb on them and thus give them a "face saving" way to surrender.
This idea being pushed by some people today that Japan had really given up before the bombs were dropped is nothing but revisionist history being pushed by people who seem to have an unnecessary guilt complex.
Also, if defense of IWO JIMA was any indication of what the Japanese would do to defend their homeland, then Truman was right to drop the Atomic Bombs. Plus we had to make Japan think we had a whole arsenal of them. If they knew we only had two, they probably would not have surrendered.