Download The Second World War Ends:

The Second World War
Ends:
The Manhattan Project and
The Defeat of Japan
Today, we will look at:
 The development of nuclear weapons
 The Pacific War
 The surrender of Japan
The Manhattan Project
• As the Nazis gained
power across Europe,
many scientists,
especially of Jewish
background, began
fleeing to the United
States
• Among these scientists
were Albert Einstein,
Enrico Fermi and Nils
Bohr; all of whom had
done extensive nuclear
research
• Once the United States
was at war, these
scientists told US
President Roosevelt
about the possibilities of
nuclear weapons
• Roosevelt was told that
Nazi Germany might
already be building
such a weapon, and
decided that the United
States should develop
the technology as well
• Under extreme secrecy, the
“Manhattan Project” began,
with the goal of producing a
nuclear weapon for the
United States
• The Project was housed at
Oak Ridges Tennessee,
employing some of the
greatest scientists in the
world
• The necessary research and
production of a usable bomb
took nearly 3 years
• The total estimated cost of
the project was $20 billion
• By the early summer
of 1945, three usable
nuclear bombs had
been produced
• One was intended for
testing, while the other
two would be reserved
for military use
• The world’s first
nuclear detonation
took place on 16 July
1945 at Los Alamos,
New Mexico
The “Trinity” Test:
16 July 1945
5:29 A.M.
“If the radiance of a thousand suns
Were to burst at once into the sky,
That would be like the splendour of the
Mighty One...
I am become Death,
The shatterer of Worlds.“
-J. Robert Oppenheimer, Project Supervisor
“Now we’re all sons of bitches”
-Ken Bainbridge, Test Director
Meanwhile,
in the Pacific Ocean…
• Since 1941, The United
States had been at war
against Japan
• The US strategy was
called “Island Hopping”,
literally taking back one
island at a time from the
Japanese
• Each island required a
major battle, each
taking the lives of
thousands of American
soldiers
• The Americans
realized that
many Japanese
soldiers were
willing to commit
suicide to assist
their country
• Quite often, US
Navy ships came
under attack
from “Kamikaze”
or suicide pilots
• The battles for Iwo Jima
(in February 1945) and
Okinawa (April 1945)
had cost nearly 20 000
American lives, and
tens of thousands more
injured
• With these losses in
mind, US leaders were
looking for a way to
avoid an invasion of the
Japanese “Home
Islands” while still
forcing a Japanese
surrender
• On 12 April, 1945, President
Roosevelt died suddenly,
and Harry S Truman
became president of the
United States
• It was only then that
Truman was made aware of
the Manhattan Project, and
of the existence of the
Nuclear Bombs
• Once the first bomb had
been successfully tested,
Truman faced a decision
about the best way to end
the war
Truman’s moral dilemma:
Is it better to risk up to 1 million American
lives in an invasion of Japan to end the
war, OR, use a new type of weapon with
enormous destructive power whose
effects are not fully known or
understood?
• Truman elected to make use of the nuclear weapons
that were now ready
• Two target cities were selected by the US military:
The cities of Hiroshima and Nagasaki
• The Japanese government was informed that the US
possessed a new type of weapon that could destroy
entire cities
• The Japanese were offered a choice: Surrender
unconditionally or face the use of these new weapons
• The ultimatum was rejected by Japan
Hiroshima:
6 August 1945
• One of the available
nuclear bombs,
nicknamed “Little
Boy” was loaded into
a US Air Force B-29
bomber
• Shortly before 9:00
am, the bomb was
dropped on the city
of Hiroshima
Hiroshima
After the Bomb
Nearly 200 000 people
were killed in the
bombing. Most of the
city of Hiroshima was
destroyed
Many people who
survived the bombing
would suffer from
radiation poisoning
over the coming years
• After Hiroshima had
been bombed, the
Japanese
government was
given another
ultimatum:
Surrender or face
another nuclear
bombing
• This warning was
also ignored
• On 9 August 1945, a
second nuclear
bomb, nicknamed
“Fat Man” was
dropped on Nagasaki
• On 14 August 1945,
the Japanese
government was
prepared to surrender
to the Allies
• The formal surrender
of Japan was signed
on 2 September 1945,
on board the US
battleship, USS
Missouri
• This ended the
Second World War, 6
years and 1 day after
it had begun