Did Truman Make the Right Decision to Use the Atomic Bomb?

Allison L., 2008-2009

The Creation of Atomic Bomb

The United States began building a bomb to protect themselves from the Axis Powers who were threatening to take control of Europe and Southeast Asia.


FDR's Decision to Commission the Building of the Bomb

Letter from Albert Einstein to FDR Updating the President of the Progress Made on Atomic Bomb

Albert Einstein fled Germany when the government began persecuting Jews in the country. Upon his arrival he informed President Roosevelt that he believed harnassing power through chain reactions could create an explosive bomb. He also believed Germany was involved in the same research.

Albert Einstein
Old Grove Rd.
Nassau Point
Peconic, Long Island
August 2d, 1939

F. R. Roosevelt
President of the United States
White House
Washington, D.C.

Some recent work by E. Fermi and L Szilard, which has been communicated to me in manuscript, leads me to expect that the element uranium may be turned into a new and important source of energy in the immediate future. Certain aspects of the situation which has arisen seem to call for watchfulness and, if necessary, quick action on the part of the Administration. I believe therefore that it is my duty to bring to your attention the following facts and recommendations.

In the course of the last four months it has been made probable- through the work of Loiot in France as well as Fermi and Szilard in America-that it may become possible to set up a nuclear chain reaction in a large mass of uranium, by which vast amounts of power and large quantities of new radium-like elements would be generated. Now it appears almost certain that this could be achieved in the immediate future.

This new phenomenon would also lead to the construction of bombs, and it is conceivable-though much less certain-that extremely powerful bombs of a new type may thus be constructed. A single bomb of this type, carried by boat and exploded in a port, might very well destroy the whole port together with some of the surrounding territory. However, such bombs might very well prove to be too heavy for transportation by air.

The United States has only very poor ores of uranium in moderate quantities. There is some good ore in Canada and the former Czechoslovakia, while the most important source of uranium is the Belgian Congo.

In view of this situation you may think it desirable to have some permanent contact maintained between the Administration and the group of physicists working on chain reactions in America. One possible way of achieving this might be for you to entrust with this task a person who has your confidence who could perhaps serve in an unofficial capacity. His task might comprise the following:

a) to approach Government Department, keep them informed of the further development, and put forward recommendations for Government actions, giving particular attention to the problems of securing a supply of uranium ore for the United States.

b) to speed up the experimental work, which is at present being carried on within the limits of the budgets of University laboratories, by providing funds, if such funds be required, through his contacts with private persons who are willing to make contributions for this cause, and perhaps also by obtaining the co-operation of industrial laboratories which have the necessary equipment.

I understand that Germany has actually stopped the sale of uranium from the Czechoslovakian mines which she has taken over. That she should have taken such an early action might perhaps be understood on the ground that the son of the German Under- Secretary of State, von Weizacker, is attached to the Kaiser- Wilhelm-Institut in Berlin where some of the American work on uranium is now being repeated.

Your very truly, (signed) A. Einstein [1]

The Manhattan Project
In 1939, the United States believed the Nazis developing an atomic bomb. In June 1942 Presdient Roosevelt decided to begin research to create one that would cause great destruction. Much of the research and testing occured in Los Alamos, New Mexico. General Leslie R. Groves, Deputy Chief of Construction of the U.S. Army Corps of Engineers, was appointed to direct this top-secret project.[2]

Results of the Manhattan Project

The Manhattan Project produced two differents of atomic bombs: Fat Man and Little Boy.

Fat Man was dropped on Nagasaki. The high explosives were designed to produce a highly accurate and symmetrical implosion. Scientists at Los Alamos were not entirely confident in the plutonium bomb design, so they scheduled the Trinity test.

The Little Boy type of bomb, which was dropped on Hiroshima, had a much simpler design than the Fat Man model. Little Boy triggered a nuclear explosion, rather than implosion. [3]

Attack on Pearl Harbor

Speech from President Roosevelt: "A Date That Will Live in Infamy"


FDR Signing Document to Declare War on Japan

FDR Signs Declaration of War


Truman and His Decision

President Truman was sworn in as the 33rd President of the United States on April 12, 1945. From July 17 to August 2 He attended a conference at Potsdam, Germany to determine the fate of Germany.

Potsdam Conference

While the US Navy was concentrating on invading Japan, the Japanese military was preparing for a land invastion. Based upon the dogged resistance at Iwo Jima and Okinawa , the allies determined that as many as 500,000 to one million allied soldiers would die if the invasion, scheduled for November 1, 1945 took place. The Potsdam Proclamation July 26, 1945 The Potsdam Declaration was broadcast to the Japanese by the Allied Forces. The demands of the Declaration created a crisis in Japan . [4]


Potsdam Conference July 28th-August 1st 1945. British Prime Minister Clement Atlee;
U.S. President Harry S. Truman; Soviet Premier Joseph Stalin. http://www.history.navy.mil/photos/images/ac00001/ac01861c.htm

On July 28, 1945 Prime Minister Suzuki announced he would ignore the proclamation.

Decision to End the War

"If they do not now accept our terms they may expect a rain of ruin from the air,
the like of which has never been seen on this earth."
-- President Harry S. Truman

Since Japan would not surrender immediately, the decision was left to President Harry Truman to either pursue a land invasion of Japan or to drop the atomic bomb. Truman had to make his decision, either to invade Japan or to drop the nuclear bomb to make a quick end to World War II.

Scenario 1: The United States Invades Japan

Japan armed almost every civilian with bamboo sticks to attack every American soldier that came upon their soil. General Douglass MacArthur of the American high command predicted a tragedy if a land invasion was required then there would be one million casualties on the American side. The United States was tired of the war and wanted a quick end. Congress exhausted all of their efforts in the war. As for the United State's economy, we had already spent so much time and billions of dollars in Germany.

Scenario 2: The United States Use the Bomb to End the Conflict with Japan

Since Truman had the bomb to his advantage, and no other nation in the world had it, he decided to demonstrate to the world how powerful it was. Truman also wanted revenge on Japan for the attacks Japan inflicted upon Pearl Harbor. Truman did not realize the true devastation of dropping the bombs. He had to make a decision that had no “historical precedence.” Truman knew there would be destruction; but he had no idea how much. He knew that the bomb would end the war with the fewest casualties. What neither he (nor the world) knew, was the horrible and tragic after effect. He did not count on the after effects being so large and dramatic.[5]

Dropping the Bombs on Japan


The atomic bomb Little Boy was dropped on Hiroshima on August 6, 1945 8:15AM
The atomic bomb Little Boy was dropped on Hiroshima on August 6, 1945 8:15AM

At 8:15 am August 6, 1945, the first atomic bomb dropped in history exploded approximately 580 meters above the city of Hiroshima. In an instant, the atomic bomb reduced the city to a scorched plain, wiping out countless precious lives and inflicting devastation on all city structures. This unprecedented tragedy was on a completely different scale from the destruction caused by natural disasters or conventional weapons. Furthermore, the large amount of radiation that instantly descended upon the earth penetrated deeply into people’s bodies, destroying cells. The death toll of Hiroshima was approximately 140,000. [6]
Jacob Beser was one of the witnesses from the Enola Gay who saw the first atomic bomb being dropped onto Hiroshima.
"I wasn't watching the radar screen. I had my own instrumentation I was concerned with.
I saw the fuse come on after the bomb separated from the aircraft, fixed time delay of about 10 seconds,
give it time to clear.
The fuse come on to get the whole thing rolling and then the thing disappeared.
Around the same time it disappeared there was this big flash which illuminated the inside of the airplane.
I couldn't wear the goggles like they were supposed to.
I was busy analyzing the environment making sure there was nothing [unplanned] happening.
I was looking for the presence of signals"[7]

- Jacob Beser August 6th, 1945

"I was reading lying on the floor with a friend of mine.
Under the eaves I saw blue flash of light just like a spark made by a train or some short circuit.
Next, a steamlike blast came."
-- Akira Onogi[8]

Dropping the Bombs on Nagasaki

The atomic bomb Fat Man was dropped on Nagasaki on August 9th, 1945.
The atomic bomb Fat Man was dropped on Nagasaki on August 9th, 1945.
Three days after Hirshima, "Fat Man" was dropped onto Nagasaki. Nagasaki approximately lost 70,000 of its citizens.

Japan Surrenders

Japan surrendered few days afterward Nagasaki, on August 14th, 1945.

Effects of the Atomic Bomb

Moral Obligations of a Country to the Rest of the World

Einstein talks with Hideki Yukawa, 1949 Nobel Laureate in Physics and John A. Wheeler, a Hopkins alumni.
Einstein talks with Hideki Yukawa, 1949 Nobel Laureate in Physics and John A. Wheeler, a Hopkins alumni.

As a result of the bombs in Japan, not only did many people die, but the consequences were far reaching. The country realized an increase in cancer, especially tyroid, breast, lung or salivary cancer. Also, any people who were in utero at the time of the bombings were born mentally retarded.

America was the most powerful country militarily after World War II.

The significance of America building its first atomic bomb demonstrates great accomplishments and grave consequences. The bombs had a major effect on Japan. Both before and after the bombings, many of the scientists who worked on the Manhattan Project regretted their involvement with the project.


  1. ^ http://www.ibiblio.org/pha/documents/einstein.html
  2. ^ http://www.cfo.doe.gov/me70/manhattan/
  3. ^ http://nuclearweaponarchive.org/Usa/Med/Lbfm.html
  4. ^ http://www.history.navy.mil/photos/events/wwii-dpl/hd-state/potsdam.htm
  5. ^ http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/index.php
  6. ^ http://www.eyewitnesstohistory.com/atomictest.htm
  7. ^ http://brucegoldfarb.com/beser.htm
  8. ^ http://www.inicom.com/hibakusha/akira.html