S T A T E M E N T O N T H E A T O M I C

B O M B

A R A D I O A D D R E S S T O T H E N A T I O N

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–––––––––––––––––––––– Harry S. Truman ––––––––––––––––––––––

Sixteen hours ago an American airplane dropped one bomb on Hiroshima, an

important Japanese Army base. That bomb had more power than 20,000 tons

of T.N.T. It had more than two thousand times the blast power of the British

“Grand Slam” which is the largest bomb ever yet used in the history of warfare.

The Japanese began the war from the air at Pearl Harbor. They have been

repaid many fold. And the end is not yet. With this bomb, we have now added a

new and revolutionary increase in destruction to supplement the growing

power of our armed forces. In their present form these bombs are now in

production and even more powerful forms are in development.

It is an atomic bomb. It is a harnessing of the basic power of the universe. The

force which the sun draws its power has been loosed against those who brought

war to the Far East.

Before 1939, it was the accepted belief of scientists that it was theoretically

possible to release atomic energy. But no one knew any practical method of

doing it. By 1942, however, we knew that the Germans were working

feverishly to find a way to add atomic energy to the other engines of war with

which they hoped to enslave the world. But they failed. We may be grateful to

Providence that the Germans got the V-1’s and V-2’s late and in limited

quantities and even more grateful that they did not get the atomic bomb at all.

The battle of the laboratories held fateful risks for us as well as the battles of

the air, land and sea, and we have now won the battle of the laboratories as we

have won other battles.

Beginning in 1940, before Pearl Harbor, scientific knowledge useful in war

was pooled between the United States and Great Britain, and many priceless

helps to our victories have come from that arrangement. Under that general

policy the research on the atomic bomb was begun. With American and British

scientists working together we entered the race of discovery against the

Germans.

The United States had available the large number of scientists of distinction in

the many needed areas of knowledge. It had the tremendous industrial and

financial resources necessary for the project and they could be devoted to it

without undue impairment of other vital war work. In the United States the

laboratory work and the production plants, on which a substantial start had

already been made, would be out of reach of enemy bombing, while at that

time Britain was exposed to constant air attack and was still threatened with the

possibility of invasion. For these reasons Prime Minister Churchill and President

Roosevelt agreed that it was wise to carry on the project here. We now have

two great plants and many lesser works devoted to the production of atomic

power. Employment during peak construction numbered 125,000 and over

65,000 individuals are even now engaged in operating the plants. Many have

worked there for two and a half years. Few know what they have been

producing. They see great quantities of material going in and they see nothing

coming out of these plants, for the physical size of the explosive charge is

exceedingly small. We have spent two billion dollars on the greatest scientific

gamble in history—and won.

But the greatest marvel is not the size of the enterprise, its secrecy, nor its

cost, but the achievement of scientific brains in putting together infinitely

complex pieces of knowledge held by many men in different fields of science

into a workable plan. And hardly less marvelous has been the capacity of

industry to design, and of labor to operate, the machines and methods to do

things never done before so that the brain child of many minds came forth in

physical shape and performed as it was supposed to do. Both science and

industry worked under the direction of the United States Army, which achieved

a unique success in managing so diverse a problem in the advancement of

knowledge in an amazingly short time. It is doubtful if such another

combination could be got together in the world. What has been done is the

greatest achievement of organized science in history. It was done under high

pressure and without failure.

We are now prepared to obliterate more rapidly and completely every

productive enterprise the Japanese have above ground in any city. We shall

destroy their docks, their factories, and their communications. Let there be no

mistake; we shall completely destroy Japan’s power to make war.

It was to spare the Japanese people from utter destruction that the ultimatum

of July 26 was issued at Potsdam. Their leaders promptly rejected that

ultimatum. 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 Secretary of War, who has kept in personal touch with all phases of the

project, will immediately make public a statement giving further details.

His statement will give facts concerning the sites at Oak Ridge near

Knoxville, Tennessee, and at Richland near Pasco, Washington, and an

installation near Santa Fe, New Mexico. Although the workers at the sites have

been making materials to be used in producing the greatest destructive force in

history they have not themselves been in danger beyond that of many other

occupations, for the utmost care has been taken of their safety.

The fact that we can release atomic energy ushers in a new era in man’s

understanding of nature’s forces. Atomic energy may in the future supplement

the power that now comes from coal, oil, and falling water, but at present it

cannot be produced on a basis to compete with them commercially. Before that

comes there must be a long period of intensive research.

It has never been the habit of the scientists of this country or the policy of this

government to withhold from the world scientific knowledge. Normally,

therefore, everything about the work with atomic energy would be made

public.

But under present circumstances it is not intended to divulge the technical

processes of production or all the military applications, pending further

examination of possible methods of protecting us and the rest of the world from

the danger of sudden destruction.

I shall recommend that the Congress of the United States consider promptly

the establishment of an appropriate commission to control the production and

use of atomic power within the United States. I shall give further consideration

and make further recommendations to the Congress as to how atomic power

can become a powerful and forceful influence towards the maintenance of

world peace.

Source: Public Papers of the President: Harry S. Truman, 1945 (Washington,

1961), pp. 197, 199. Reprinted in Judgment at the Smithsonian, edited by Philip

Nobile (New York: Marlowe & Company, 1995), pp. 88–91.