(Following is a letter from Senator John F. Kennedy to Thomas E. Murray, former member of the Atomic Energy Commission, in reply to his open letter dated September 6, 1960, addressed to the presidential candidates)

     DEAR MR. MURRAY: Your thoughtful letter of September 6 is greatly appreciated.
     I wholeheartedly concur in your opinion that the issue of nuclear weapon tests should not be exploited for partisan advantage. This subject, like all other public issues, is properly a matter for critical discussion and debate. But on this question - as on all other important issues - differences of opinion should be explored with responsible debate and with a full appreciation of the gravity of the question.
     Your letter urges both presidential candidates to espouse the proposition that although the present ban on atmospheric tests should be retained, underground tests and tests in outer space should now be resumed, for the explicit purpose of developing nuclear weapons suitable for rational military purposes.
     I do not agree that undergound nuclear weapons tests should be resumed at this time. Should the American people choose me as their President, I would want to exhaust all reasonable opportunities to conclude an effective international agreement banning all tests - with effective international inspection and controls - before ordering a resumption of tests.
     The Geneva Conference on Discontinuance of Nuclear Weapons Tests has been prolonged and generally discouraging. Even so, substantial progress has been made toward reaching agreement on some important phases of the problem.
     The people of the United States, like millions of people all over the world, are anxiously hoping for an effective and realistic agreement outlawing nuclear tests - which means an agreement that is not dependent upon faith alone, but one enforceable through an effective system of international inspection and controls.
     I have always considered the conclusion of such an agreement of extreme importance not only to the people of the present nuclear powers, but for all mankind. This is true because new advances in technology have brought atomic weapons within reach of several additional nations.
     For the United States to resume tests at this time might well result in a precipitate breakdown of the Geneva negotiations and a propaganda victory for the Soviets.
     Under these circumstances I do not now recommend a resumption of testing. The question is not one of political courage. A man might courageously follow either course of action. The question is, which course of action is right.
     It is possible that our negotiators, who have earnestly tried to negotiate a realistic and effective test ban, have exhausted every avenue of agreement, but since I have neither taken part in the negotiations nor had personal reports from the negotiators, who are not representatives chosen by me, I lack personal assurance of the futility of further discussion which alone would persuade me to urge the abandonment of so high an objective.
     The Geneva Conference has been in progress, off and on, for almost 2 years. Despite the complexity of the subject, it should be possible within a reasonable period of time to find out whether the representatives of the Soviet Union are really prepared to enter into an effective test ban. If the Soviet Union still refused, after our earnest efforts, the world would then know where the responsibility lay.
     Accordingly, it is my intention, if I am elected President, to pursue the following course of action:
     1. During my administration the United States will not be the first to begin nuclear tests in the world's atmosphere to contaminate the air that all must breathe and thus endanger the lives of future generations.
     2. If the present nuclear weapons test conference is still in progress when I am elected, I will direct vigorous negotiation, in accordance with my personal instructions on policy, in the hope of concluding a realistic and effective agreement.
     3. Should the current Geneva Conference have been terminated before January 20, 1961, I will immediately thereafter invite Great Britain, France, and the Soviet Union to participate in a new, and I would hope far more successful, conference on nuclear weapons test.
     4. In either event, I intend to prescribe a reasonable but definite time limit within which to determine whether significant progress is being made.
     At the beginning of the period, I would direct the Atomic Energy Commission to proceed with preliminary preparations for underground tests of the type in which radioactive substances would be forever sealed within the explosive cavity. If, within the period, the Russians remain unwilling to accept a realistic and effective agreement, then the world will know who is to blame. The prompt resumption of underground tests to develop peaceful uses of atomic energy, research in the field of seismic technology and improvement of nuclear weapons should then be considered, as may appear appropriate in the situation then existing.
     5. I would also invite leading nations having industrial capacity for production of nuclear weapons to a conference to seek and, if possible, to agree upon means of international control of both the production and use of weapons grade fissionable material and also the production of nuclear weapons.
     6. I will earnestly seek an overall disarmament agreement of which limitations upon nuclear weapons tests, weapons grade fissionable material, biological and chemical warfare agents will be an essential and integral part.