[Goose]

From a historians perspective you can only analyze what happened almost 80 years ago in light of the knowledge you had then, but it is very hard to ignore the now.  We and the British did not break the Venona code until 1946 and we began to have a clearer understanding of how much of our secrets were then in Russian hands.

Totally agree here. It is also I think worth of note that the "long telegram" was not sent until Feb 22,  1946 and the Truman Doctrine was not promulgated until March 12, 1947. While it is undoubtedly true that there were some people who were concerned about Russia in August of 1945, they obviously had not yet attained any traction among the decision makers. The US was exclusively concerned about winning the war as quickly as possible and at the same time at the lowest US casualty count possible. Anything else was secondary. Those two goals work directly against each other in most cases. The nuclear option was one thing that addressed both, and for that reason was inevitable. Add to that the vested interest and military inertia of those involved and it seems hard to imagine any decision but using it. Even after the war was won and the Truman doctrine announced, the Truman administrations actions and defense policy clearly shows they did not actually appreciate the USSR's threat potential. Part of that was the "We have the bomb and they don't" thinking, but most of it was an underestimation of the USSR.

The naval blockade option was a very long shot in large measure because the Navy had been uniquely successful in accomplishing what Germany could not (against Britain) and what had never been done previously. No nation in history had ever been defeated by naval blockade alone. Everybody got invaded. The concept that Japan would be thus defeated seemed fanciful in that light. It could have been argued that waiting for Japan to be significantly weakened and then invading would have been a plausible choice. However, the US would have been required to maintain an absolutely enormous army sitting ready to go for months, which was considered impossible. The troops were getting tired of war, the nation was getting tired of war. Having lots of troops sitting doing nothing was considered unacceptable from a morale point of view and a political point of view. Ironically, getting more people killed was viewed as more acceptable than doing nothing.

It also must be noted that not invading would surrender the initiative. This is something that military forces never like to do. Keeping the pressure on allows you, at least in theory, to dictate events. Not doing so risks the enemy figuring out a way to dictate events, never a good thing. It is tempting to say that Japan was so weakened it couldn't do that, but doing so smacks of hubris. Nobody wanted to lose the war at the last minute by doing anything less than all we could. Arguably, the blockade would have worked, but nobody was willing to do the experiment.

The Russian actions on Sakhalin island actually would not have let to an invasion of even northern Japan because Russia did not have the shipping to do it. They had literally nothing in that area. They could bring troops to Japan in very limited numbers and very slowly. Even if these troops prevailed they absolutely could not have been supplied and would have run out of food and ammunition very quickly. It was a "no go". This was independent of any naval action by Japan.

[Goose]

From a historians perspective you can only analyze what happened almost 80 years ago in light of the knowledge you had then, but it is very hard to ignore the now.  We and the British did not break the Venona code until 1946 and we began to have a clearer understanding of how much of our secrets were then in Russian hands.

Totally agree here. It is also I think worth of note that the "long telegram" was not sent until Feb 22,  1946 and the Truman Doctrine was not promulgated until March 12, 1947. While it is undoubtedly true that there were some people who were concerned about Russia in August of 1945, they obviously had not yet attained any traction among the decision makers. The US was exclusively concerned about winning the war as quickly as possible and at the same time at the lowest US casualty count possible. Anything else was secondary. Those two goals work directly against each other in most cases. The nuclear option was one thing that addressed both, and for that reason was inevitable. Add to that the vested interest and military inertia of those involved and it seems hard to imagine any decision but using it. Even after the war was won and the Truman doctrine announced, the Truman administrations actions and defense policy clearly shows they did not actually appreciate the USSR's threat potential. Part of that was the "We have the bomb and they don't" thinking, but most of it was an underestimation of the USSR.

The naval blockade option was a very long shot in large measure because the Navy had been uniquely successful in accomplishing what Germany could not (against Britain) and what had never been done previously. No nation in history had ever been defeated by naval blockade alone. Everybody got invaded. The concept that Japan would be thus defeated seemed fanciful in that light. It could have been argued that waiting for Japan to be significantly weakened and then invading would have been a plausible choice. However, the US would have been required to maintain an absolutely enormous army sitting ready to go for months, which was considered impossible. The troops were getting tired of war, the nation was getting tired of war. Having lots of troops sitting doing nothing was considered unacceptable from a morale point of view and a political point of view. Ironically, getting more people killed was viewed as more acceptable than doing nothing.

It also must be noted that not invading would surrender the initiative. This is something that military forces never like to do. Keeping the pressure on allows you, at least in theory, to dictate events. Not doing so risks the enemy figuring out a way to dictate events, never a good thing. It is tempting to say that Japan was so weakened it couldn't do that, but doing so smacks of hubris. Nobody wanted to lose the war at the last minute by doing anything less than all we could. Arguably, the blockade would have worked, but nobody was willing to do the experiment.

The Russian actions on Sakhalin island actually would not have let to an invasion of even northern Japan because Russia did not have the shipping to do it. They had literally nothing in that area. They could bring troops to Japan in very limited numbers and very slowly. Even if these troops prevailed they absolutely could not have been supplied and would have run out of food and ammunition very quickly. It was a "no go". This was independent of any naval action by Japan.