Good evening:
     Seventeen years ago man unleashed the power of the atom. He thereby took into his mortal hands the power of self-extinction. Throughout the years that have followed, under three successive Presidents, the United States has sought to banish this weapon from the arsenals of individual nations. For of all the awesome responsibilities entrusted to this office, none is more somber to contemplate than the special statutory authority to employ nuclear arms in the defense of our people and freedom.
     But until mankind has banished both war and its instruments of destruction, the United States must maintain an effective quantity and quality of nuclear weapons, so deployed and protected as to be capable of surviving any surprise attack and devastating the attacker. Only through such strength can we be certain of deterring a nuclear strike, or an overwhelming ground attack, upon our forces and our allies. Only through such strength can we in the free world - should that deterrent fail - face the tragedy of another war with any hope of survival. And that deterrent strength, if it is to be effective and credible when compared with that of any other nation, must embody the most modern, the most reliable and the most versatile nuclear weapons our research and development can produce.
     The testing of new weapons and their effects is necessarily a part of that research and development process. Without tests - to experiment and verify - progress is limited. A nation which is refraining from tests obviously cannot match the gains of a nation conducting tests. And when all nuclear powers refrain from testing, the nuclear arms race is held in check.
     That is why this Nation has long urged an effective worldwide end to nuclear tests. And this is why in 1958 we voluntarily subscribed, as did the Soviet Union, to a nuclear test moratorium, during which neither side would conduct new nuclear tests, and both East and West would seek concrete plans for their control.
     But on September first of last year, while the United States and the United Kingdom were negotiating in good faith at Geneva, the Soviet Union callously broke its moratorium with a two month series of tests of more than 40 nuclear weapons. Preparations for these tests had been secretly underway for many months. Accompanied by new threats and new tactics of terror, these tests - conducted mostly in the atmosphere - represented a major Soviet effort to put nuclear weapons back into the arms race.
     Once it was apparent that new appeals and proposals were to no avail, I authorized on September fifth a resumption of U.S. nuclear tests underground, and I announced on November second - before the close of the Soviet series - that preparations were being ordered for a resumption of atmospheric tests, and that we would make whatever tests our security required in the light of Soviet gains.
     This week, the National Security Council of the United States has completed its review of this subject. The scope of the Soviet tests has been carefully reviewed by the most competent scientists in the country. The scope and justification of proposed American tests have been carefully reviewed, determining which experiments can be safely deferred, which can be deleted, which can be combined or conducted underground, and which are essential to our military and scientific progress. Careful attention has been given to the limiting of radioactive fallout, to the future course of arms control diplomacy, and to our obligations to other nations.
     Every alternative was examined. Every avenue of obtaining Soviet agreement was explored. We were determined not to rush into imitating their tests. And we were equally determined to do only what our own security required us to do. Although the complex preparations have continued at full speed while these facts were being uncovered, no single decision of this Administration has been more thoroughly or more thoughtfully weighed.
     Having carefully considered these findings - having received the unanimous recommendations of the pertinent department and agency heads - and having observed the Soviet Union's refusal to accept any agreement which would inhibit its freedom to test extensively after preparing secretly - I have today authorized the Atomic Energy Commission and the Department of Defense to conduct a series of nuclear tests - beginning when our preparations are completed, in the latter part of April, and to be concluded as quickly as possible (within two or three months) - such series, involving only those tests which cannot be held underground, to take place in the atmosphere over the Pacific Ocean.
     These tests are to be conducted under conditions which restrict the radioactive fallout to an absolute minimum, far less than the contamination created by last fall's Soviet series. By paying careful attention to location, wind and weather conditions, and by holding these tests over the open seas, we intend to rule out any problem of fallout in the immediate area of testing. Moreover, we will hold the increase in radiation in the Northern Hemisphere, where nearly all such fallout will occur, to a very low level.
     Natural radioactivity, as everyone knows, has always been a part of the air around us, with certain long-range biological effects. By conservative estimate, the total effects from this test series will be roughly equal to only 1 percent of those due to this natural background. It has been estimated, in fact, that the exposure due to radioactivity from these tests will be less than 1/50 of the difference which can be experienced, due to variations in natural radioactivity, simply by living in different locations in our own country. This will obviously be well within the guides for general population health and safety, as set by the Federal Radiation Council; and considerably less than 1/l0 of 1 percent of the exposure guides set for adults who work with industrial radioactivity.
     Nevertheless, I find it deeply regrettable that any radioactive material must be added to the atmosphere - that even one additional individual's health may be risked in the foreseeable future. And however remote and infinitesimal those hazards may be, I still exceedingly regret the necessity of balancing these hazards against the hazards to hundreds of millions of lives which would be created by any relative decline in our nuclear strength.
     In the absence of any major shift in Soviet policies, no American President - responsible for the freedom and the safety of so many people - could in good faith make any other decision. But because our nuclear posture affects the security of all Americans and all free men - because this issue has aroused such widespread concern - I want to share with you and all the world, to the fullest extent our security permits, all of the facts and the thoughts which have gone into this decision.
     Many of these facts are hard to explain in simple terms - many are hard to face in a peaceful world - but these are facts which must be faced and must be understood.

     Had the Soviet tests of last fall merely reflected a new effort in intimidation and bluff, our security would not have been affected. But in fact they also reflected a highly sophisticated technology, the trial of novel designs and techniques, and some substantial gains in weaponry. Many of these tests were aimed at improving their defenses against missiles - others were proof tests, trying out existing weapons systems - but over one-half emphasized the development of new weapons, particularly those of greater explosive power.
     A primary purpose of these tests was the development of warheads which weigh very little compared to the destructive efficiency of their thermonuclear yield. One Soviet test weapon exploded with the force of 58 megatons - the equivalent of 58 million tons of TNT. This was a reduced-yield version of their much-publicized hundred-megaton bomb. Today, Soviet missiles do not appear able to carry so heavy a warhead. But there is no avoiding the fact that other Soviet tests, in the 1 to 5 megaton range and up, were aimed at unleashing increased destructive power in warheads actually capable of delivery by existing missiles.
     Much has also been said about Soviet claims for an anti-missile missile. Some of the Soviet tests which measured the effects of high altitude nuclear explosion - in one case over 100 miles high - were related to this problem. While apparently seeking information on the effects of nuclear blasts on radar and communication, which is important in developing an anti-missile defense system, these tests did not, in our judgment, reflect a developed system.
     In short, last fall's tests, in and by themselves, did not give the Soviet Union superiority in nuclear power. They did, however, provide the Soviet laboratories with a mass of data and experience on which, over the next two or three years, they can base significant analyses, experiments and extrapolations, preparing for the next test series which would confirm and advance their findings.
     And I must report to you in all candor that further Soviet tests, in the absence of further Western progress, could well provide the Soviet Union with a nuclear attack and defense capability so powerful as to encourage aggressive designs. Were we to stand still while the Soviets surpassed us - or even appeared to surpass us - the Free World's ability to deter, to survive and to respond to an all-out attack would be seriously weakened.

     The fact of the matter is that we cannot make similar strides without testing in the atmosphere as well as underground. For, in many areas of nuclear weapons research, we have reached the point where our progress is stifled without experiments in every environment. The information from our last series of atmospheric tests in 1958 has all been analyzed and re-analyzed. It cannot tell us more without new data. And it is in these very areas of research - missile penetration and missile defense - that further major Soviet tests, in the absence of further Western tests, might endanger our deterrent.
     In addition to proof tests of existing systems, two different types of tests have therefore been decided upon. The first and most important are called "effects tests" - determining what effect an enemy nuclear explosion would have upon our ability to survive and respond. We are spending great sums of money on radar to alert our defenses and to develop possible anti-missile systems - on the communications which enable our command and control centers to direct a response - on hardening our missiles sites, shielding our missiles and warheads from defensive action, and providing them with electronic guidance systems to find their targets. But we cannot be certain how much of this preparation will turn out to be useless: blacked out, paralyzed or destroyed by the complex effects of a nuclear explosion.
     We know enough from earlier tests to be concerned about such phenomena. We know that the Soviets conducted such tests last fall. But until we measure the effects of actual explosions in the atmosphere under realistic conditions, we will not know precisely how to prepare our future defenses, how best to equip our missiles for penetration of an anti-missile system, or whether it is possible to achieve such a system for ourselves.
     Secondly, we must test in the atmosphere to permit the development of those more advanced concepts and more effective, efficient weapons which, in the light of Soviet tests, are deemed essential to our security. Nuclear weapons technology is a constantly changing field. If our weapons are to be more secure, more flexible in their use and more selective in their impact - if we are to be alert to new breakthroughs, to experiment with new designs - if we are to maintain our scientific momentum and leadership - then our weapons progress must not be limited to theory or to the confines of laboratories and caves.
     This series is designed to lead to many important, if not always dramatic, results. Improving the nuclear yield per pound of weight in our weapons will make them easier to move, protect and fire - more likely to survive a surprise attack - and more adequate for effective retaliation. It will also, even more importantly, enable us to add to our missiles certain penetration aids and decoys, and to make those missiles effective at high altitude detonations, in order to render ineffective any anti-missile or interceptor system an enemy might some day develop.
     Whenever possible, these development tests will be held underground. But the larger explosions can only be tested in the atmosphere. And while our technology in smaller weapons is unmatched, we now know that the Soviets have made major gains in developing larger weapons of low-weight and high explosive content - of 1 to 5 megatons and upward. Fourteen of their tests last fall were in this category, for a total of 30 such tests over the years. The United States, on the other hand, had conducted, prior to the moratorium, a total of only 20 tests within this megaton range.

     While we will be conducting far fewer tests than the Soviets, with far less fallout, there will still be those in other countries who will urge us to refrain from testing at all. Perhaps they forget that this country long refrained from testing, and sought to ban all tests, while the Soviets were secretly preparing new explosions. Perhaps they forget the Soviet threats of last autumn and their arbitrary rejection of all appeals and proposals, from both the United States and the United Nations. But those free peoples who value their freedom and their security, and look to our relative strength to shield them from danger - those who know of our good faith in seeking an end to testing and an end to the arms race - will, I am confident, want the United States to do whatever it must do to deter the threat of aggression.
     If they felt we could be swayed by threats or intimidation - if they thought we could permit a repetition of last summer's deception - then surely they would lose faith in our will and our wisdom as well as our weaponry. I have no doubt that most of our friends around the world have shared my own hope that we would never find it necessary to test again - and my own belief that, in the long run, the only real security in this age of nuclear peril rests not in armament but in disarmament. But I am equally certain that they would insist on our testing once that is deemed necessary to protect free world security. They know we are not deciding to test for political or psychological reasons - and they also know that we cannot avoid such tests for political or psychological reasons.

     The leaders of the Soviet Union are also watching this decision. Should we fail to follow the dictates of our own security, they will chalk it up, not to goodwill, but to a failure of will - not to our confidence in Western superiority, but to our fear of world opinion, the very world opinion for which they showed such contempt. They could well be encouraged by such signs of weakness to seek another period of no testing without controls - another opportunity for stifling our progress while secretly preparing, on the basis of last fall's experiments, for the new test series which might alter the balance of power. With such a one-sided advantage, why would they change their strategy, or refrain from testing, merely because we refrained? Why would they want to halt their drive to surpass us in nuclear technology? And why would they ever consider accepting a true test ban or mutual disarmament?
     Our reasons for testing and our peaceful intentions are clear - so clear that even the Soviets could not objectively regard our resumption of tests, following their own resumption of tests, as provocative or preparatory for war. On the contrary, it is my hope that the prospects for peace may actually be strengthened by this decision - once the Soviet leaders realize that the West will no longer stand still, negotiating in good faith, while they reject inspection and are free to prepare for further tests. As new disarmament talks approach, the basic lesson of some three years and 353 negotiating sessions at Geneva is this - that the Soviets will not agree to an effective ban on nuclear tests as long as a new series of offers and prolonged negotiations, or a new uninspected moratorium, or a new agreement without controls, would enable them once again to prevent the West from testing while they prepare in secret.
     But inasmuch as this choice is now no longer open to them, let us hope that they will take a different attitude on banning nuclear tests - that they will prefer to see the nuclear arms race checked instead of intensified, with all the dangers that that intensification brings: the spread of nuclear weapons to other nations; the constant increase in world tensions; the steady decrease in all prospects for disarmament; and, with it, a steady decrease in the security of us all.

     If the Soviets should change their position, we will have an opportunity to learn it immediately. On the 14th of March, in Geneva, Switzerland, a new 18-power conference on disarmament will begin. A statement of agreed principles has been worked out with the Soviets and endorsed by the U.N. In the long run, it is the constructive possibilities of this conference - and not the testing of new destructive weapons - on which rest the hopes of all mankind. However dim those hopes may sometimes seem, they can never be abandoned. And however far-off most steps toward disarmament appear, there are some that can be taken at once.
     The United States will offer at the Geneva conference - not in the advance expectation they will be rejected, and not merely for purposes of propaganda - a series of concrete plans for a major "breakthrough to peace." We hope and believe that they will appeal to all nations opposed to war. They will include specific proposals for fair and enforceable agreements: to halt the production of fissionable materials and nuclear weapons and their transfer to other nations - to convert them from weapon stockpiles to peaceable uses - to destroy the warheads and the delivery systems that threaten man's existence - to check the dangers of surprise and accidental attack - to reserve outer space for peaceful use - and progressively to reduce all armed forces in such a way as ultimately to remove forever all threats and thoughts of war.
     And of greatest importance to our discussion tonight, we shall, in association with the United Kingdom, present once again our proposals for a separate comprehensive treaty - with appropriate arrangements for detection and verification - to halt permanently the testing of all nuclear weapons, in every environment: in the air, in outer space, under ground and under water. New modifications will also be offered in the light of new experience.
     The essential arguments and facts relating to such a treaty are well-known to the Soviet Union. There is no need for further repetition, propaganda or delay. The fact that both sides have decided to resume testing only emphasizes the need for new agreement, not new argument. And before charging that this decision shatters all hopes for agreement, the Soviets should recall that we were willing to work out with them, for joint submission to the United Nations, an agreed statement of disarmament principles at the very time their autumn tests were being conducted. And Mr. Khrushchev knows, as he said in 1960, that any nation which broke the moratorium could expect other nations to be "forced to take the same road."
     Our negotiators will be ready to talk about this treaty even before the Conference begins on March 14th - and they will be ready to sign well before the date on which our tests are ready to begin. That date is still nearly two months away. If the Soviet Union should now be willing to accept such a treaty, to sign it before the latter part of April, and apply it immediately - if all testing can thus be actually halted - then the nuclear arms race would be slowed down at last - the security of the United States and its ability to meet its commitments would be safeguarded - and there would be no need for our tests to begin.
     But this must be a fully effective treaty. We know now enough about broken negotiations, secret preparations, and the advantages gained from a long test series never to offer again an uninspected moratorium. Some may urge us to try it again, keeping our preparations to test in a constant state of readiness. But in actual practice, particularly in a society of free choice, we cannot keep top-flight scientists concentrating on the preparation of an experiment which may or may not take place on an uncertain date in the undefined future. Nor can large technical laboratories be kept fully alert on a stand-by basis waiting for some other nation to break an agreement. This is not merely difficult or inconvenient - we have explored this alternative thoroughly, and found it impossible of execution.
     In short, in the absence of a firm agreement that would halt nuclear tests by the latter part of April, we shall go ahead with our talks - striving for some new avenue of agreement - but we shall also go ahead with our tests. If, on the other hand, the Soviet Union should accept such a treaty in the opening month of talks, that single step would be a monumental step toward peace - and both Prime Minister Macmillan and I would think it fitting to meet Chairman Khrushchev at Geneva to sign the final pact.

     For our ultimate objective is not to test for the sake of testing. Our real objective is to make our own tests unnecessary, to prevent others from testing, to prevent the nuclear arms race from mushrooming out of control, to take the first steps toward general and complete disarmament. And that is why, in the last analysis, it is the leaders of the Soviet Union who must bear the heavy responsibility of choosing, in the weeks that lie ahead, whether we proceed with these steps - or proceed with new tests.
     If they are convinced that their interests can no longer be served by the present course of events, then it is my fervent hope that they will agree to an effective treaty. But if they persist in rejecting all means of true inspection, then we shall be left with no choice but to keep our own defensives arsenal adequate for the security of all free men.
     It is our hope and prayer that these grim, unwelcome tests will never have to be made - that these deadly weapons will never have to be fired - and that our preparations for war will bring about the preservation of peace. Our foremost aim is the control of force, not the pursuit of force, in a world made safe for mankind. But whatever the future brings, I am sworn to uphold and defend the freedom of the American people - and I intend to do whatever must be done to fulfill that solemn obligation.
    Thank you - and good night.