This did not mean that he intended to threaten the Russians with the use of the bomb against them. Indeed he waited another week before almost casually informing Stalin of its existence, and then did so in terms so vague that had Stalin not been already well-informed through his spy network it might have meant little to him. What it did mean was that the Americans ceased to have an interest in getting the Russians to enter the war against Japan, and were therefore no longer hobbled by this consideration in arguing with them about Poland and the other puppet régimes which they were imposing in Eastern Europe.5 Henceforward it was the Russians who wanted to get in before the peace, and the Americans who had become indifferent. This new freedom however only released the flow of American argument and not the peoples of Hungary, Bulgaria and Roumania, where the Russians remained firmly in occupation and control.
Truman half, but only half, realized the qualitative difference between the new bomb and the previous use of massive quantities of high explosive. He recorded in his diary for July 25th: ‘It is certainly a good thing for the world that Hitler’s crowd or Stalin’s did not discover the atomic bomb. It seems to me the most terrible thing ever discovered, but it can be made the most useful.’10 This immediately followed a passage in which he said that he had instructed Stimson to use it only against military objectives so that ‘soldiers and sailors are the target and not women and children’.11 (Quite how this was reconcilable with what happened at Hiroshima, and still less with Hiroshima plus Nagasaki, is difficult to see. In reality with a weapon of such force, the distinction was unsustainable.)
What had been deliberately decided by Truman and his advisers was that it should not be used against Tokyo or Kyoto. But this saved face and buildings of note, not lives. The second or Nagasaki bomb seems to have been dropped, five days after the Hiroshima one, under a single authorization and without intermediate civilian re-appraisal. (It was a bomb of a somewhat different type but its release could hardly have been justified on the need for further experiment.6) The issue here is tied up with whether more explicit warnings should have been given to the Japanese, both before Hiroshima and between then and Nagasaki, and whether indeed a demonstration in the waters of Tokyo Bay might have been equally effective.
These issues were in turn entangled with a dispute within the US Administration as to whether the unfortunate commitment to unconditional surrender could be interpreted sufficiently elastically to allow the Emperor of Japan to remain upon the throne. An undecisive approach to this, partly in deference to ‘progressive’ opinion, made it more difficult to send clear messages which might have achieved peace without carnage.7 The Americans were also subject to the inhibition that they started with a total of only four bombs. Nagasaki used up the last but one. They did not therefore feel that they had much margin to spare for error, explosions which did not occur, or demonstrations which failed to convince. Furthermore they were impatient to end the war before the Russians could become effectively involved, and start making in Asia the territorial and political demands which were disfiguring Eastern Europe.
Truman therefore allowed the two bombs to be dropped and the world to enter a new era; and he did so with a good conscience. At the time the decision did not lie heavy upon his mind, and he did not subsequently regret it. The case in his favour is considerable. He believed he was saving rather than sacrificing lives by acting as he did, and he may well have been right. Certainly no alternative figure with whom the ultimate decision could conceivably have rested-Roosevelt, Churchill, Attlee-would have acted otherwise. Equally certainly he did not offend Stalin or provide the Soviet determination to catch up by dropping the bomb. Stalin, when told by Truman at Potsdam what he broadly already knew, answered that he hoped the Americans would make good use of the weapon against Japan. What spurred the Russian nuclear programme was the knowledge that the Americans had the bomb, not their decision to use it. Possession Truman could not conceivably have concealed.
The case against him, Nagasaki apart, which in retrospect at least looks unnecessary and therefore inexcusable, is almost more one of style than of substance. He took the decisions and received the results of their being executed with an inappropriate lack of sombreness and sensitivity. He could be excused for not wholly foreseeing the qualitative nature of the change over which he was presiding. Very few people did. But he knew the immediate destructiveness, even if not the longer-term damage of the weapon he had unleashed. His reaction on board USS Augusta, when news of the successful attack on Hiroshima came through, which was that of rushing round the ship and proclaiming the news with glee, does not sound right. Nor does his laconic diary comment on the White House staff conference on the morning after Nagasaki ‘Nothing unusual to discuss.’8 No doubt a wringing of hands would have served no purpose other than that of self-indulgence. But he was too brutal about those with less strong stomachs. When Robert Oppenheimer, a key figure in the development of the bomb, expressed remorse a few months after its use, Truman told Acheson that he had no patience with such a ‘cry-baby’.12