All of this sheds important light on the question of whether the Allied demand for "unconditional surrender" helped prolong the war.

The "unconditional surrender" policy is often presented by revisionists as something akin to a demand for national self-immolation by the defeated power. In truth, "unconditional surrender," a joint Anglo-American policy, reflected the Allies' bad experience with the endgame of World War I and its aftermath in the Versailles non-settlement. An armistice, it was felt, had ill served the cause of peace in 1918; among other things, it had made possible the "stab-in-the-back" theory proposed by the German military, which, in turn, helped to delegitimate the Weimar Republic and prepare the rise of Hitler. Against that background, an armistice with a still aggressive Japan (which to this day has yet to acknowledge, much less apologize for, its role in starting the Pacific War) seemed an unlikely way to secure the peace.

Given those concerns about the relationship of the war's endgame to the future possibilities of peace, given the mass bloodletting on Iwo Jima and Okinawa, and given the Japanese leaders' determination to continue the war, what were Harry Truman's real options in the early summer of 1945?

He could proceed with Olympic and Coronet, with American casualties reliably estimated in the hundreds of thousands and Japanese deaths in the millions.

He could continue the fire-bombing of Japanese cities, which on one night (March 9-10, 1945) had turned the Shitamachi section of Tokyo into an inferno, burning out sixteen square miles of the city and killing between 80,000 and 100,000 civilians.

He could tighten the blockade of Japan, starving the Japanese to death or into submission.

He could try a "demonstration" of the atomic bomb, in the hope that that would persuade the Japanese leadership to quit.

He could wait and see what happened.

He could make a deal with the Japanese to end the fighting while allowing Japan to retain at least some of the territory it had conquered since 1931.

Or he could use the new atomic weapons, in the hope that this, plus the Soviet entry into the war, would shock the Japanese leadership into accepting the terms of the Potsdam Declaration: which, properly interpreted, would allow the imperial system to continue as a constitutional monarchy, if that was what the Japanese people freely decided.

Deal-making short of unconditional surrender would have involved a betrayal, not simply of Allied policy, but of the Allies' legitimate war aims, which involved the dismantling of fascist and militarist systems as necessary preconditions to an enduring peace. Cutting a deal with Japan would also have been politically suicidal; after Pearl Harbor, the Bataan Death March, Guadalcanal, Saipan, Tarawa, Iwo Jima, the Japanese destruction of Manila, the kamikaze attacks, and Okinawa, the American people would almost certainly have demanded the removal from office of a president who failed to see the war through to a conclusion that vindicated their children's sacrifice by creating the conditions for the possibility of a real peace.

Sitting tight and waiting would simply have reinforced the position of the most intransigent elements in the Japanese civilian and military leadership, while permitting the Soviet Union to occupy chunks of northeast Asia, including all of Korea and Sakhalin (and perhaps Hokkaido). Sitting tight would also have meant the deaths of tens of thousands of Allied prisoners of war, whom the Japanese were preparing to slaughter in order to ease the task of homeland defense.

A "demonstration" of the bomb risked a stiffening of Japanese intransigence in the event of failure. But even a successful "demonstration" was unlikely to have the desired, decisive effect. On August 9, three days after Hiroshima and the day after Nagasaki, War Minister General Korechika Anami told the Japanese Cabinet, "We cannot pretend victory is near, but it is far too early to say the war is lost."

Firebombing Japanese cities and/or starving Japan would have resulted in colossal civilian death tolls, with no guarantee of surrender over the short or perhaps even medium term. The people who had contrived Banzai Cliff and Suicide Cliff on Saipan were likely to absorb a mind-boggling amount of punishment before giving in.

In sum: there was little evidence in July 1945 that the Japanese were prepared to quit the war on acceptable terms any time soon, and considerable evidence (some of which has only now become public, with the declassification of the MAGIC intercepts available to Truman) that Japanese military leaders were actively preparing to pursue hostilities through any number of means. A "peace party" existed within the Japanese civilian leadership, but it was weak. Strengthening its hand seemed, reasonably enough, the most effective and humane way, and perhaps the only way, to bring the war to a conclusion that would make an enduring peace possible, and without turning Japan into an abattoir.