(narrator) In 1942,
the United States set up a highly secret effort
known as the Manhattan Project
to develop the atomic bomb.
Under the command of American physicist Robert Oppenheimer,
it brought together some of the world's greatest thinkers.
The making of the atomic bomb
was conducted in an atmosphere of urgency.
Many believed that Germany was on the road
to developing its own atomic weapon.
After months of secret work,
the first atomic bomb
was set off near Alamogordo, New Mexico,
on July 16, 1945.
Its destructive power
was a thousand times greater than anything ever seen before.
The world had entered the nuclear age.
With Germany's surrender
and the swearing in of Harry Truman as president,
the stage was set in the spring of 1945
for the final push against Japan.
Saipan's fall the previous summer,
combined with the knowledge of how the U.S. had bombed Germany,
made it obvious
that the United States would obliterate Japan's cities.
Yet the Japanese were dedicated to their emperor,
believing that his voice was the voice of God.
They felt that divine providence would do away with the invaders.
If the United States had invaded,
the Japanese would have fought to the last man.
General MacArthur told Secretary of War Stimson
that the invasion...
[man as General MacArthur] "Would cost over a million casualties
to American forces alone."
(narrator) A war department report
concluded that defeating Japan
would cost the Japanese 5 to 10 million deaths.
By the summer of 1945,
American fliers controlled Japan's skies.
American napalm had killed more than 400,000 Japanese
and injured nearly 500,000.
9 million Japanese were homeless.
On July 26th, President Truman issued the Potsdam Declaration:
"Japan shall be given an opportunity to end the war,
surrender, or face utter and complete destruction."
Let there be no mistake.
We shall completely destroy Japan's power to make war.
If they do not now accept our terms,
they may expect a reign of ruin from the air,
the like of which has never been seen on this earth.
(narrator) On August 4th,
720,000 leaflets were dropped on Hiroshima
urging everyone to get out
and indicating that the place was going to be obliterated.
On August 6th, Colonel Paul Tibbets,
commanding the B-29 superfortress Enola Gay,
named after his mother,
dropped the atomic bomb on Hiroshima, Japan.
Over 100,000 people were killed instantly.
Yet there was still no surrender.
A second bomb was dropped on Nagasaki on August 9th.
Finally, on August 14th, Emperor Hirohito surrendered.
Many years later,
a Japanese pilot, Mitsuo Fuchida,
who led the attack on Pearl Harbor,
told Colonel Tibbets:
[man as Fuchida] "You did the right thing.
"You know the Japanese attitude at that time,
"how fanatic they were.
"They'd die for the Emperor.
"Every man, woman, and child
"would have resisted that invasion
with sticks and stones if necessary."