I was discussing this with a friend the other day, and he claimed that Truman's true intent was not saving American lives because the Japanese were already planning to surrender to the Soviets. Instead, the bomb was a first act of the cold war, i.e. to prevent the Soviets from making a foray into the Asian theater.
I was stopped in my tracks because I really don't know enough about it, but I found the claim suspiscious as the Soviets didn't really have an Asian front to speak of.
So is there any historical evidence to support these claims: that Japan was planning to surrender to the Soviets and that Truman put a stop to it by levelling Hiroshima and Nagasaki?
Hi there, while you await further answers on this topic, you may be interested in this section of our FAQ, which has a few answers that go into the "why drop the bomb" question as well as "did the Soviet invasion of Manchuria or the atomic bombings actually end the war." Thanks!
OK... let's break this down.
First of all, I'm not sure I like the language about Truman dropping the a-bomb. He really wasn't in the planning process at all. The a-bomb was already in development before he was aware of it, as were the schedules, and the bombing site selection. All of that happened without his knowledge or approval. He didn't even know the a-bomb existed until after he was sworn into office as president in April 1945. The a-bomb was viewed at the time as just another weapon, and the military had full control over it. The first real decision Truman made regarding the a-bombs was when he ordered the military to stop bombing after Nagasaki. Truman didn't make the order to drop the a-bomb, he simply tacitly went along with the existing US Army plans. The decision to bomb Japan was made in mid-1943. Once that happened it just kinda kept on schedule.
Second, the Japanese were not trying to surrender to the Soviets. The Japanese weren't even at war with the Soviets when the first a-bomb was dropped. The Soviets did however declare war on the Japanese three days later. What the Japanese were trying to do, was use the Soviets as an intermediary to surrender to the US. They just wanted to surrender on very favorable terms. Basically they wanted to keep their pre-war empire, which is something the US wasn't going to allow.
Third, far from trying to prevent the Soviets from opening an Asian front, the US had specifically asked the Soviets to join the war against the Japanese. And the Soviet gains for doing so had already been hammered out in advance. The Soviets were to occupy Manchuria, North Korea, South Sakhalin, and the Kuril Islands. The agreement held and the Soviets literally handed some areas back to the US (mainly parts of South Korea) in order to honor that agreement. There was concern that the Soviets might grab more than the agreement assigned to him, but in the end he was true to his word. He declared war on Japan like the US requested, and he only occupied the agreed upon areas. Perhaps he would have done more had the Japanese not surrendered when they did, but that's pure speculation.
Fourth, Japan did surrender to the Soviets, or more precisely the United Nations which included the Soviet Union. When they signed the surrender agreement, the Soviets were one of the ten allied signatories. I'm not sure signing a separate agreement with the Soviets would have helped the Japanese anyway. A separate agreement wouldn't have prevented the US from continuing their war, not unless the Soviets were prepared to intevene on behalf of the Japanese, which they absolutely weren't prepared to do.
The idea that the atomic bombs were partially a political point to the Soviets to "watch out" has been around for a while. And it has some validity. The US political and military leaders were concerned about post war Soviet intentions. A little intimidation in that direction was considered a good thing. Certainly when Truman mentioned the atomic bombs to Stalin at Potsdam he was trying to get a better deal from Stalin. But there is no indication that he ever changed their intended use, let alone in order to influence the Soviets.