In his book “Meeting at Potsdam”, author Charles L. Mee suggested that Truman agreed to dropping the A-bombs on Hiroshima and Nagasaki not just to prevent a huge death toll to both American invaders and Japanese civilians but, more importantly, so he wouldn’t have to share the spoils of Japan with Stalin.
According to Mee, at the Potsdam Conference following the end of the War in Europe, Truman was routinely frustrated by Stalin because he would suggest ways to divide Europe between the US and the USSR, only to have Stalin shoot it down. Unfortunately for Truman, during WWII, when Roosevelt met with Stalin and Churchill at the Yalta and Malta conferences, he not only never recorded any of the details of those conferences, he never informed Truman of their discussions. Thus, Truman went in blind.
So, after some very trying negotiations with Stalin over Europe, Truman didn’t want a repetition over Japan. As a result, while the Russians were still in the process of transporting troops and materiel from the Eastern front to the coast, Truman trumped him by dropping the bombs and forcing Japan to capitulate.
In the late 60s and early 70s, as a young sailor, I was stationed in Japan and visited both Hiroshima as well as Pearl Harbor in Honolulu. It is important for Americans to know that it wasn’t until the late 90s that Japan finally acknowledged their surprise attack on Pearl Harbor. Prior to that time, the Japanese people were never told by their government that Japan had attacked first. It wasn’t taught in their schools, it wasn’t in their libraries and it wasn’t in their archives. As young American servicemen, we found ourselves engaged in any number of disagreements with our Japanese hosts over Pearl Harbor and the dropping of the bombs on Hiroshima and Nagasaki.
In the mid- to late 80s, a survey was done in Japan to see how contemporary Japanese felt about the dropping of the bombs, their surrender to America and life in Japan since the end of the war. Surprisingly, ~80% agreed that the way the war ended for them and the things that happened afterward were far better than if Japan had been able to continue either under their former feudal system or under the thumb of the Russians.
It was also in the late 80s or early 90s that the Japanese government admitted what it did to the Korean women that were captured when Japan invaded Korea. The women were taken hostage and brought to Japan where they were forced to become “comfort women” (sex slaves) for the Japanese soldiers.
It is likely that, as more time passes, Japan may, ultimately, develop an attitude about the war that many young Germans have developed about Hitler and the Nazis. In their revisionist world, Hitler and the Nazis never happended and were just an excuse manufactured by Americans to take over Germany as part of our “imperial” empire.
So, if we fail to teach all of these things not only to OUR children but to German and Japanese children (to name a few), the past will be prologue.
Odds are not only would we have had to fight in Japan to overthrow Tojo, we would also have wound up fighting in Japan afterwards to stop the Reds from taking the entire country.
I recall someone who was at the USS Arizona Memorial at Pearl Harbor (1990s) where they met a teenage American visitor who believed that Japan's attack on Pearl Harbor was in response to the bombing of Hiroshima and Nagasaki.