Signers of the statement, unprecedented in the annals of science (with the possible exception of a secret memorandum submitted to the government just before the A-bomb was used), included such outstanding physicists as Hans A. Bethe of Cornell; Kenneth T. Bainbridge of Harvard; Samuel K. Allison, University of Chicago; Dean George B. Pegram, Columbia; C. C. Lauritsen, California Institute of Technology; Bruno Rossi and Victor F. Weisskopf, Massachusetts Institute of Technology; F. W. Loomis and Frederick Seitz, University of Illinois; Merle A. Tuve, Carnegie Institution of Washington; R. B. Brode, University of California; and M. G. White, Princeton—all, with the exception of Dr. Tuve, professors of physics at their respective universities. Those among them who did not directly participate in the development of the A-bomb played major parts in other scientific wartime projects, such as radar and the proximity fuse. Implicit in their statement was the first confirmation—indeed, the most authoritative we have had so far from scientists with first-hand knowledge of the subject—that a hydrogen bomb of a thousand times the power of the A-bomb could be made. More than that, they informed us that Russia may complete the H-bomb in less than four years, meaning, of course, that we too could achieve the same goal in the same period. We were thus provided by the experts with a time-table on which we must act if we are not to run the risk of Russia’s getting the H-bomb ahead of us, and so being in a position to use it, or threaten its use, against the nations of western Europe, as the greatest blackmail weapon in history. The statement summarizes in essence the principal points of view that have been advanced so far on what policy we should adopt on the H-bomb, and since it was promulgated by men known to have definite inside knowledge of the subject, it deserves closer scrutiny than it has hitherto received. “It was stated correctly,” they inform us at the outset, that a hydrogen bomb, if it can be made, would be capable of developing a power 1,000 times greater than the present atomic bomb. New York, or any of the greatest cities of the world, could be destroyed by a single hydrogen bomb. We believe that no nation has the right to use such a bomb, no matter how righteous its cause. The bomb is no longer a weapon of war, but a means of extermination of whole populations. Its use would be a betrayal of morality and of Christian civilization itself. Senator Brien McMahon has pointed out to the American people that the possession of the hydrogen bomb will not give positive security to this country. We shall not have a monopoly of this bomb, but it is certain that the Russians will be able to make one, too. In the case of the fission bomb the Russians required four years to parallel our development. _In the case of the hydrogen bomb they will probably need a shorter time._