Lecture 7

Nuclear Plan Modification

1. In spring 1945 it became obvious that the US nuclear bomb would not be ready before Germany’s collapse. That triggered discussion of plan modifications.  Namely, project organizers questioned the use of the bomb in Japan and need to continue research.
   
2. Hans Bethe, who headed the Theoretical Division at Los Alamos, was astonished when Groves presented the situation and new plans in February, saying "I am amazed both by the conclusion not to use [the bomb] on Germany and secondly by their reasons [for targeting the Japanese fleet]. We [the scientists] had no idea of such a decision. We were under the impression that Germany was the first target until the German surrender. That was my belief. Obviously, it was wrong."
   
3. Compounding the variation of the global nuclear situation was the recent change in the American presidency.  On April 12, 1945 President Roosevelt dies, and Vice President Harry S. Truman is sworn in.  As vice president, Truman does not know about the nuclear bomb.  While he is updated, scientists debate the morality of the bomb. For Truman, the morality is never questioned.  He decides the war has been going on too long, that any voluntary postponement of its finish would be grounds for his own impeachment.  A new goal is made for the nuclear weapon: Forcing Japanese unconditional surrender to avoid extended jungle war and invasion of the Japanese islands.

Political Discussions

1. Issued at Potsdam July 26, 1945, the Potsdam Declaration was a proclamation Defining Terms for Japanese Surrender:
   "We, the President of the United States, the President of the National Government of the Republic of China, and the Prime Minister of Great Britain, representing the hundreds of millions of our countrymen, have conferred and agree that Japan shall be given an opportunity to end this war.  We call upon the government of Japan to proclaim now the unconditional surrender of all Japanese armed forces, and to provide proper and adequate assurances of their good faith in such action. The alternative for Japan is prompt and utter destruction. The only obstacle for the Japanese was acceptance the term “unconditional surrender” Meaning humiliation, loss of face, loss of emperor, loss of Japanese soul."
2. Setting the Test Date, July 2, 1945 - President Truman had delayed his meeting with Stalin until the atomic bomb could be tested. On July 2, General Groves told Robert Oppenheimer that the test date was being set by "the upper crust.“
3. Truman Tells Stalin, July 24, 1945 - At the Potsdam Conference in defeated Germany, President Truman told Stalin only that the U.S. "had a new weapon of unusual destructive force."
4. Truman Diary, July 25, 1945 – President Truman wrote in his diary: “I told the Sec. of War to use it so that military objectives and soldiers and sailors are the target and not women and children. Even if the Japs are savages, ruthless, merciless and fanatic, we as the leader of the world for the common welfare cannot drop that terrible bomb on the old capital or the new.”  (The target was to be a purely military one!)
5. Official Bombing Order, July 25, 1945 – The bombing order issued to General Spaatz made no mention of targeting military objectives or sparing civilians. The cities themselves were the targets.

Mission to Hiroshima

1. Hiroshima - Middle size coastal city founded in 1594 and built on six islands.  In 1945, the city had a population of 350,000 people.  It served as a local military command center, but was mainly commercial and industrial, oriented around several small shipyards.
2. At approximately 2:00 on the morning of August 6th, the Enola Gay, which was carrying an atomic bomb (Little Boy), started on the long flight from Tinian.  The Bomb, Little Boy, exploded at approximately 8:15 A.M. above the “A-Bomb Dome” at an altitude of 2,000 ft.
3. The shock wave traveled the first 2.3 miles in 10 seconds.  Wind speeds were measured at 1000 miles/hour.  Shock pressure was measured at 700000 lbs/square meter.  Shock temperature ~2000000 degrees Celcius.  There were instantly 70,000 deaths, though over 140,000 subsequent deaths have been recorded.

Nagasaki

1. Nagasaki was at the bottom of the pre-identified list of the Target Committee.  Weather conditions dictated the choice.  The reason for being on the target list was a concern for the psychological effect.  Nagasaki was added shortly before the first mission as the last on the list of alternate targets. Kyoto was considered to be the first choice because of its history, as the ancient capital, and "the advantage of the people being more highly intelligent, and hence, better able to appreciate the significance of the weapon.“  These factors were present in Nagasaki as well. The city had been an ancient center of trade with foreign countries, first with China, Vietnam and South Asia.  Later when trade with the outside world was cut off, Nagasaki remained a  Portuguese outpost. Nagasaki was a religious center for Catholicism as well as Buddhism. As a result, literacy was high. In addition, it held vital war related industry, being the home of the Mitsubishi Aircraft plant and the Ohashi Arms factory.
   
2. So, Why drop a second bomb?  Hiroshima has been justified as a way to save the lives that an invasion of Japan would cause. It has been explained as a way to impress the Russians and ensure American superiority in Asia. By August, 1945, the Japanese were all but defeated. The Soviet declaration of war was scheduled for August 15.
3. 1. “When you have to deal with a beast you have to treat him as a beast"   –President Harry S. Truman, August 1945.  
   2. "Now is the time to exterminate the Yellow Peril for all time… Let the rats squeal" —Congressman Charles A. Plumley, August 1945. 

Japan’s Surrender

1. On September 2, 1945, on board of battleship Missouri in Tokyo Bay, Gen. MacArthur referred to the nuclear bomb attacks on Hiroshima and Nagasaki, saying they had "revised the traditional concept of war."

Japanese surrender, Tokyo Bay, September 2, 1945. Photograph courtesy U.S. National Archives.