OK

This, we can't pin on Dr. Win-The-War. He may have approved the project that developed the atomic bomb, but he didn't give the command to use it. That grave responsibility fell on the man he chose to be his Vice President before the 1944 Democratic National Convention, a moderate internationalist Midwestern senator from Missouri, Harry S. Truman, because FDR passed away April 12, 1945.

Below the great orange obi for a discussion of the process, the results, and some of the implications.

You won't be surprised to know that the subject of the use of the bomb to end World War II is one of the most active historiographical (that's the study of the writing of history for you non-professionals) issues among American historians even now, almost 70 years after the events of August 1945. You may even remember the to-do over the wall cards when the Enola Gay was first exhibited at the new Smithsonian Air and Space museum in 1996. As Frank Rich noted in June 1996

the museum . . .  shelved a comprehensive and contentious exhibition about the dropping of the atom bomb on Japan, substituting a simple display of the Enola Gay accompanied by reminiscences of its crew.
It's never going to be a simple issue, so let's start with the development of the bomb and then look at its use and the aftermath.

The Manhattan Project

It seems that in the fall of 1941, before Pearl Harbor, the Roosevelt administration got word that Germany was working on a weapon to end all weapons. Four days after Pearl Harbor, FDR authorized Vannevar Bush (no relation), the director of the administration's Office of Scientific Research and Development, to develop an atomic bomb.By June 1942, it was obvious that the Army had to build the facilities to produce the materials for the bomb. The project was assigned to the Manhattan Engineering District of the Army Corps of Engineers, hence the Manhattan Project.

The project brought together the top scientists in the country, including recent exiles from Nazi and Fascist Europe, and companies like DuPont. Three sites were developed: in Oak Ridge, Tennessee and Hanford, Washington, (that's the F Reactor plutonium production complex at Hanford)
both adjacent to dams constructed as part of the New Deal, the apparatus was constructed to produce the fissionable materials, and in Los Alamos, New Mexico, the research and development  lab worked on how exactly to deliver these materials in a bomb. Brigadier General Leslie Groves, who had overseen the construction of the Pentagon (also a New Deal project), supervised, and he selected a leftist physicist from UC Berkeley, J. Robert Oppenheimer, to direct operations at Los Alamos, which has been called
the greatest floating seminar of physicists ever assembled.
By the late winter of 1945 it was clear that two bombs, one that used uranium-235 and one that used Plutonium, might be ready by the summer. Different designs were needed fore each: the U-235 bomb, which used a gun assembly, was called "Little Boy" (originally "Thin Man" after the Dashiell Hammett novel); the plutonium bomb, which used a shaped charge to squeeze the material into a critical mass, was called "Fat Man" (after the character Sydney Greenstreet played in The Maltese Falcon). The implosion device was tested on July 16 1945, well after Harry Truman became President, and this is what it looked like in the New Mexico dawn.
Oppenheimer later said that the detonation brought to mind a line from the Bhagavad-Gita
Now I am become Death, the destroyer of worlds.
Truman gets filled in

Truman wasn't entirely in the dark about the Manhattan Project. As a senator he had been able to establish a special investigating committee to monitor the cost of the War in 1941 before Pearl Harbor, so he knew about it, only just as something that was top secret. When Truman took office, the military estimated it would take another eighteen months until we could invade the mainland of Japan. On April 25, 1945, he was briefed on the bomb by Secretary of War Henry Stimson, and it appears that what registered was the responsibility he would have to authorize its use: he reportedly said

I'll make the decision, but it is terrifying to think about what I will have to decide.
But, of course, what this meant was the creation of an interim advisory committee which consulted both the scientists and the corporations (Westinghouse, Union Carbide, DuPont), and was advised by the War Department that the power of these weapons was so fearful they would hasten the end of the war. As the historian Sean Malloy notes, the development of the bomb
resulted in a weapon optimized for the destruction of cities and the killing of civilians
Planning was left to the military, because, after all, it was a weapon, and the military decided that use of the weapon might save American lives.  In fact, some historians suggest that the question about using the bomb should be phrased thus:Would the Japanese have surrendered without either use of the bomb or an invasion of the home islands, which was scheduled to begin in November 1945. An invasion might have cost a million American lives and enormous devastation to Japan. In the political climate of 1945 after V-E Day it is difficult to imagine that the American leadership would sacrifice American servicemen to save Japanese civilians (yes, there's a decidedly racist component to this argument); further, the firebombing of Tokyo, which had begun in Tokyo March 9, would certainly have continued.

Hiroshima and Nagasaki

I suppose that we should be relieved that the Allies had only two bombs, and that there was always the risk that, if the test bomb had failed to work, the impact of this terrible new weapon would have been squandered.  On July 25, the acting chief of staff of the Armed Forces gave direction that

the 509 Composite Group, 20th Air Force will deliver its first special bomb as soon as weather will permit visual bombing after about 3 August 1945 on one of the targets: Hiroshima, Kokura, Niigata, and Nagasaki.
American intelligence knew that the Japanese had moved 600,000 troops onto the island of Kyushu, and this suggested that they thought they could repulse an invasion.

Thus, on the morning of August 6, 1945, Paul Tibbets climbed into the cockpit of his plane, the Enola Gay, which he had named after his mother, knowing he had one of the special weapons loaded onto the bomb bay, and at 8:15 AM, he dropped the bomb on the heavily militarized and industrialized city of Hiroshima. Its objective was to force Japan to surrender. On August 7, planes continued their usual conventional bombing runs, dropping leaflets over other Japanese cities to inform them Hiroshima had been destroyed. The following day, the Soviet Union informed Japan that the two nations were now at war, and Truman went on the air to announce that what had happened at Hiroshima was

only a warning of things to come.
On the 9th, the target was supposed to be the city of Kokura on Kyushu, but the target was obscured by clouds and smog. So the bombers flew on to the other major city on Kyushu, the port city Nagasaki where the Mitsubishi shipyards were, and dropped their bomb at about 11:00 AM.  Here's the cloud over Nagasaki
and here's the Urakami district of Nagasaki where the bomb was dropped. The reason the Cathedral is still standing is that the bomb exploded directly over it.
Emperor Hirohito announced that Japan was leaving the war August 14 and the formal surrender took place September 2.

The Aftermath

The historiography is still complicated, so I'll give you my take. I can understand why they used the bomb on Hiroshima if only to show it off, but I have a harder time understanding why Nagasaki was bombed only three days later, if at all.  I'm still at the same point where I was in 1972, after reading a book that argued that the bombing especially of Nagasaki was supposed to make an impression on the Soviet Union. We know that the bomb has not been used again, but we still fear the possibility that an unscrupulous nation will be able to develop one. I'm heartened by the fact that neither Pakistan nor India have decided to nuke each other.

This is also where I give my midterm exam. Tuesday, to tie up some loose ends, I'll have some more thoughts on nativism, this time in the labor movement, and the next installment after that, two weeks from today, will deal with some aspects of America in the 1950s.

A note on sources
My notes on this are based on two books: Paul Boyer, By the Bomb's Early Light: American Thought and Culture at the Dawn of the Atomic Age and David Kennedy, Freedom from Fear: The American People in Depression and War, 1929-1945. I fleshed my notes out with the help ofWilson Miscamble, The Most Controversial Decision: Truman, the Atomic Bombs and the Defeat of Japan. The best book on the Manhattan Project is Richard Rhodes, The Making of the Atomic Bomb .

5:37 PM PT: You will notice that toward the end of the comment thread, one Kossack has warned you not to read this diary because I'm biased, and that conclusion is based on my not having said something that I most certainly said.

So two questions. Should I unpublish this? Or do you want to deal with the warning yourself?

EMAIL TO A FRIEND X
Your Email has been sent.