The document summarizes the key events leading up to and following the atomic bombings of Hiroshima and Nagasaki by the United States during World War II. It describes the development of the atomic bomb through the Manhattan Project, the rejection of the Potsdam Declaration by Japan, and President Truman's decision to drop bombs on Hiroshima and Nagasaki. It then details the immediate and long-term effects of the bombings, including widespread destruction and loss of life as well as long-term health impacts like radiation sickness, cancers, and birth defects. An atomic bomb casualty commission was later established to study the effects on survivors.

1. PART I : ANATOMY OF A PLAN
 Key Elements :
1> Emperor Showa :
Also referred to by his personal name, Hirohito, Emperor Showa aided in the transformation of a rural and agricultural
Japan to an industrialized militaristic empire in the 1930’s. These actions eventually lead to Japan’s involvement in
WWII, which resulted in the complete devastation of Japan. During the occupation of Japan following the war he saw
rise to the rebirth of a highly urbanized modern Japan.
2> Second Sino-Japanese War:
Imperial Japan invaded China in 1937, creating a war between themselves and the Chinese Communists and
Nationalists. The Japanese committed infamous atrocities on the civilian population of China. Some estimates claim
that up to 20 million Chinese were killed during WWII. Chinese Nationalist and Communist forces eventually formed
an alliance against the Japanese. The shameful mutilation of women claimed 20,000 to 80,000citizens as the Imperial
Japanese army swept through Manchuria.
3> The Manhattan Project:
The secret U.S. project to create the first atomic weapon was known as the Manhattan Project. In August 1942 the U.S.
Army was given the responsibility of organizing the efforts of British and U.S. physicists to seek a way to harness
nuclear energy for military purposes.Working in collaboration with the United Kingdom and Canada, with their
respective projects Tube Alloys and Chalk River Laboratories, the project designed and built the first atomic bombs.
The scientific research was directed by American physicist J. Robert Oppenheimer, and the overall project was under
the authority of General Leslie Groves, of the U.S. Army Corps of Engineers.
 The Cause :
1> The Physicists :
After the invasion of Poland by Nazi Germany in 1939, the physicists Albert Einstein and Leo Szilard warned the
U.S. government of the danger threatening all of humanity if the Nazis should be the first to make a nuclear bomb.
Oppenheimer then began to seek a process for the separation of uranium-235 from natural uranium and to determine
the critical mass of uranium required to make such a bomb. This triggered the Manhattan project.
2> The Potsdam Ultimatum :
On July 26, Truman and other Allied leaders issued the Potsdam Declaration outlining terms of surrender for Japan. It
was presented as an ultimatum and stated that without surrender, the Allies would attack Japan, resulting in "the
inevitable and complete destruction of the Japanese armed forces and just as inevitably the utter devastation of the
Japanese homeland". The atomic bomb was not mentioned in the communiqué.
3> The Reply :
On July 28, Japanese papers reported that the declaration had been rejected by the Japanese government. That
afternoon, Prime Minister Kantarō Suzuki declared at a press conference that the Potsdam Declaration was no more
than a rehash of the Cairo Declaration and that the government intended to ignore it. The statement was taken by both
Japanese and foreign papers as a clear rejection of the declaration. Emperor Hirohito, who was waiting for a Soviet
reply to noncommittal Japanese peace feelers, made no move to change the government position. On July 31, he made
clear to his advisor Kōichi Kido that the Imperial Regalia of Japan had to be defended at all costs.
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2.  The Factors :
1> The USA did not want to invade Japan.
2> Only way to make Japan surrender.
3> Need to justify the cost of building the bomb and man hours spent working.
4> They reasoned that using the A-bomb would deliver a huge blow to Japan.
5> This would save the lives lakhs of American troops.
6> Give U.S. more power in rebuilding Europe.
7> Mounting tensions with Russia would end.
8> It would end the war.
 The Decision :
Preliminary research on Atomic bombs had begun in 1939, originally because of fear that Nazi Germany would develop
atomic weapons first. In May 1945, the defeat of Germany caused the focus to turn to possible use against the Japanese. In
early July, on his way to Potsdam, Truman had re-examined the decision to use the bomb. In the end, President Truman
made the decision to drop the atomic bombs on Japan. His stated intention in ordering the bombings was to bring about
a quick resolution of the war by inflicting destruction and instilling fear of further destruction in sufficient strength to cause
Japan to surrender.
 The Choice Of Targets :
On May 10–11, 1945, the Target Committee at Los Alamos, led by J. Robert Oppenheimer, recommended Kyoto, Niigata,
Hiroshima, Yokohama, and the arsenal at Kokura as possible targets. The target selection was subject to the following
criteria:
1> The target was larger than three miles (5 km) in diameter and was an important target in a large urban area.
2> The blast would create effective damage.
3> The target was unlikely to be attacked by August 1945.
The Target Committee stated that "It was agreed that psychological factors in the target selection were of great importance.
Two aspects of these are :
1>Obtaining the greatest psychological effect against Japan and
2>Making the initial use sufficiently spectacular for the importance of the weapon to be internationally recognized.
Hiroshima was described as "an important army depot and port of embarkation in the middle of an urban industrial area. It
is a good radar target and it is such a size that a large part of the city could be extensively damaged. There are adjacent hills
which are likely to produce a focusing effect which would considerably increase the blast damage. Due to rivers it is not a
good incendiary target."
Kyoto had the advantage of being an important center for military industry, as well an intellectual center and hence better
able to appreciate the significance of the weapon. The Emperor's palace in Tokyo has a greater fame than any other target
but is of least strategic value.
During World War II, Edwin O. Reischauer was the Japan expert for the U.S. Army Intelligence Service, in which role he
is incorrectly said to have prevented the bombing of Kyoto.In his autobiography, Reischauer specifically refuted the
validity of this claim:"...the only person deserving credit for saving Kyoto from destruction is Henry L. Stimson, the
Secretary of War at the time, who had known and admired Kyoto ever since his honeymoon there several decades earlier."
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3. PART II : ANATOMY OF THE EXECUTION
HIROSHIMA
 The Take- Off:
Hiroshima was the primary target of the first nuclear bombing mission on August 6, with Kokura and Nagasaki being
alternative targets. August 6 was chosen because clouds had previously obscured the target. A Superfortress bomber named
the Enola Gay, piloted and commanded by 509th Composite Group commander Colonel Paul Tibbets, was launched from
the West Pacific, about six hours flight time from Japan. The Enola Gay was accompanied by two other flights :
1>The Great Artiste, commanded by Major Charles W. Sweeney, carried instrumentation.
2> The Necessary Evil (a photography aircraft) was commanded by Captain George Marquardt.
During the journey, Navy Captain William Parsons had armed the bomb, which had been left unarmed to minimize the
risks during takeoff. Parsons thought while arming "Little Boy": "I knew the Japs were in for it, but I felt no particular
emotion about it."
"Little Boy" was created using uranium-235, a radioactive isotope of uranium. This uranium-235 atomic bomb, a product of
$2 billion of research, had never been tested. Nor had any atomic bomb yet been dropped from a plane. Some scientists and
politicians pushed for not warning Japan of the bombing in order to save face in case the bomb malfunctioned.
About an hour before the bombing, Japanese early warning radar detected the approach of some American aircraft headed
for the southern part of Japan. An alert was given. At nearly 08:00, the radar operator in Hiroshima determined that the
number of planes coming in was probably not more than threeand the air raid alert was lifted. To conserve fuel and aircraft,
the Japanese had decided not to intercept small formations.
 The Bombing :
The weather detector aircraft informed Enla Gay that Hiroshima was having a clear weather. At 8:15 a.m. (local time), the
Enola Gay's door sprang open and dropped "Little Boy." The bomb exploded 1,900 feet above the city and only missed
the target, the Aioi Bridge, by approximately 800 feet.
Staff Sergeant George Caron, the tail gunner, described what he saw: "The mushroom cloud itself was a spectacular sight, a
bubbling mass of purple-gray smoke and you could see it had a red core in it and everything was burning inside. . . . It
looked like lava or molasses covering a whole city. . . ."
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4.  Immediate Effects :
It created a blast equivalent to about 13 kilotons of TNT (54 TJ). Mind you, The U-235 weapon was considered very
inefficient, with only 1.38% of its material fissioning. The radius of total destruction was about 1.6 km, with resulting fires
across 11 km2.Hiroshima's population has been estimated at 350,000; approximately 70,000 died immediately from the
explosion and another 70,000 died from radiation within five years.Over 90% of the doctors and 93% of the nurses in
Hiroshima were killed or injured—most had been in the downtown area which received the greatest damage.
A survivor described the damage to people: ―The appearance of people was . . . well, they all had skin blackened by burns.
They had no hair because their hair was burned, and at a glance you couldn't tell whether you were looking at them from in
front or in back. . . . They held their arms bent [forward] . . . and their skin - not only on their hands, but on their faces and
bodies too - hung down. . . . If there had been only one or two such people . . . perhaps I would not have had such a strong
impression. But wherever I walked I met these people. . . . Many of them died along the road - I can still picture them in my
mind -- like walking ghosts.
Before Bombing After Bombing
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5. NAGASAKI
 The Statement :
After the Hiroshima bombing, President Truman issued a statement :
―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. Behind this air attack will follow sea and land forces in such numbers and power as they have not yet seen and
with the fighting skill of which they are already well aware.‖
The Japanese government still did not react to the Potsdam Declaration.
 The Second Flight :
"Fat Man" While the people of Japan tried to comprehend the devastation in Hiroshima, the United
States was preparing a second bombing mission. The second run was not delayed in
order to give Japan time to surrender, but was waiting only for a sufficient amount of
plutonium-239 for the atomic bomb. On August 9, 1945 only three days after the
bombing of Hiroshima, another B-29, Bock's Car left for Japan at 3:49 a.m.
The first choice target for this bombing run had been Kokura. Since the haze over
Kokura prevented the sighting of the bombing target, Bock's Car continued on to its
second target. At 11:02 a.m., the atomic bomb, "Fat Man," was dropped over Nagasaki.
 The Results :
The atomic bomb exploded 1,650 feet above the city.The explosion generated
heat estimated at 3,900 degrees Celsius and winds that were estimated at 1005
km/h.Casualty estimates for immediate deaths range from 40,000 to 75,000.
Total deaths by the end of 1945 may have reached 80,000.
Estimates of total deaths by the end of 1945 from burns, radiation and related
disease, the effects of which were aggravated by lack of medical resources,
range from 90,000 to 166,000. Some estimates state up to 200,000 had died by
1950, due to cancer and other long-term effects.
Until August 9, the war council had still insisted on its four conditions for
surrender. On that day Hirohito ordered Kido to "quickly control the situation
... because the Soviet Union has declared war against us." He then held an
Imperial conference during which he authorized minister Tōgō to notify the
Allies that Japan would accept their terms on one condition, that the declaration
"does not compromise any demand which prejudices the prerogatives of His
Majesty as a Sovereign ruler."
In his declaration, Hirohito referred to the atomic bombings:
Moreover, the enemy now possesses a new and terrible weapon with the power
to destroy many innocent lives and do incalculable damage. Should we continue to fight, not only would it result in an
ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization.
Such being the case, how are We to save the millions of Our subjects, or to atone Ourselves before the hallowed spirits of
Our Imperial Ancestors?
This is the reason why we have ordered the acceptance of the provisions of the Joint Declaration of the Powers.
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6. PART III : ANATOMY OF THERAMIFICATIONS
 Aftermath :
 The wind velocity on the ground beneath the explosion center was 980 miles/hr. Within 0.3 seconds of detonation, the
fireball high in the air grew to a diameter of more than 200 meters. The temperature on the surface was 7,000 degrees C.
 Most deaths and injuries occurred when people were trapped in their burning houses or struck by debris.
 Of the city’s 90,000 buildings, 60,000 were destroyed.
 This left many survivors homeless.
 At the end of the bombing, more than 220,000 people died from both bombs.
 An estimated total of 237,000 related deaths resulted from the explosion.
 Diseases :
 Black Rain :
Soon after the explosion, a giant mushroom cloud billowed upward, carrying dirt,
dust, and other debris high into the air. After the explosion, soot generated by the
conflagration was carried by hot air high into the sky. this dust and soot became
radioactive, mixed with water vapor in the air, then fell back to earth in what came to
be called "black rain.―
The black rain contained radioactive material. Fish died and floated to the surface in
the ponds and rivers where this rain fell. Many of the people who drank from wells in
Black Rain
areas where the black rain fell suffered from diarrhea for three months.
 Cataracts :
The patient was exposed 820m from the hypocenter and had white cloudiness in both eyes. The dark
area in the center of this photo is the cloudiness caused by an A-bomb cataract. Cataracts occurred
several months to several years after exposure.
 Leukemia :
Leukemia is cancer of the blood. The white blood cells multiply wildly without fully maturing. Red blood cells and
platelets are reduced, leading to anemia. The white blood cells increase in number but lose normal functioning, which
lowers resistance to infection. The incidence of leukemia was greatest 7 to 8 years after the bombing.
 Cancer :
Cancers began to increase about 1960. Some cancers for which a correspondence has been confirmed between distance
from the incidence are: myeloma, ovary cancer, urinary tract cancer, breast cancer, colon cancer, lung cancer, esophagus
cancer, stomach cancer.
 Birth Defects :
Radiation harmed fetuses in various ways. Some were stillborn. Development tended to be slower than that of other
children. Some were born with abnormally small heads, a condition known as microcephaly. Those who were exposed
close to the hypocenter were likely to display severe mental retardation that renders them unable to manage everyday life
without assistance.
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7.  Atomic Bomb Casualty Commission:
In the spring of 1948, the Atomic Bomb Casualty Commission (ABCC) was established in accordance with a presidential
directive from Harry S. Truman to the National Academy of Sciences–National Research Council to conduct investigations
of the late effects of radiation among the survivors in Hiroshima and Nagasaki.
Among the casualties were found many unintended victims, including Allied POWs, Korean and Chinese laborers, students
from Malaya on scholarships, and some 3,200 Japanese American citizens.
One of the early studies conducted by the ABCC was on the outcome of pregnancies occurring in Hiroshima and Nagasaki,
and in a control city, Kure located 18 miles (29 km) south from Hiroshima, in order to discern the conditions and outcomes
related to radiation exposure.
One author has claimed that the ABCC refused to provide medical treatment to the survivors for better research results. In
1975, the Radiation Effects Research Foundation was created to assume the responsibilities of ABCC.
 The Opposition :
 Albert Einstein was a critic of the bombing and was against it. He sent a letter to the president saying that the bombs
weren’t necessary.
 Leo Szilard is one of the many people against the bombing of Hiroshima and Nagasaki.
 Peter Kuznick was the director of the Nuclear Studies Institute at American University.
He said of the president:
‖He knew he was beginning the process of annihilation of the species. It was not just a war crime; it was a crime against
humanity."
 Jimmy Carter visited Hiroshima and wrote this memorial :
―This memorial must be a constant and permanent reminder for all people to work for
peace and better understanding.‖
 Looking Forward :
A testimony to Japan’s staggering resilience is the visible fact of the enormity of Hiroshima’s and Nagasaki’spost-
bombing development. The bombs still couldn’t stop its domination of the Electronic Industry.
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