My dear Professor Cate:
Your letter of December 6, 1952 has just now been delivered to me.
When the message came to Potsdam that a successful atomic explosion had taken place in New Mexico, there was much excitement and conversation about the effect on the war then in progress with Japan.
The next day I told the Prime Minister of Great Britain and Gereralissimo Stalin that the explosion had been a success. The British Prime Minister understood and appreciated what I'd told him. Premier Stalin smiled and thanked me for reporting the explosion to him, but I'm sure he did not understand its significance.
I called a meeting of the Secretary of State, Mr. Byrnes, the Secretary of War, Mr. Stimson, Admiral Leahy, General Marshall, General Eisenhower, Admiral King and some others, to discuss what should be done with this awful weapon.
I asked General Marshall what it would cost in lives to land on Tokio plain and other places in Japan. It was his opinion that such an invasion would cost at a minimum one quarter of a million casualties, and might cost as much as a million, on the American side alone, with an equal number of the enemy. The other military and naval men present agreed.
I asked Secretary Stimson which cities in Japan were devoted exclusively to war production. He promptly named Hiroshima and Nagasaki, among others.
We sent an ultimatum to Japan. It was rejected.
I ordered atomic bombs dropped on the two cities named on the way back from Potsdam, when we were in the middle of the Atlantic Ocean.
In your letter, you raise the fact that the directive to General Spaatz to prepare for delivering the bomb is dated July 25. It was, of course, necessary to set the military wheels in motion, as these orders did, but the final decision was in my hands, and was not made until we were returning from Potsdam.
Dropping the bombs ended the war, saved lives, and gave the free nations a chance to face the facts.
When it looked as if Japan would quit, Russia hurried into the fray less than a week before the surrender, so as to be in at the settlement. No military contribution was made by the Russians toward victory over Japan. Prisoners were surrendered and Manchuria occupied by the Soviets, as was Korea, north of the 38th parallel.