Few listen, but three popes have said it:
112. Hence justice, right reason, and the recognition of (human) dignity cry out insistently for a cessation to the arms race. The stock-piles of armaments which have been built up in various countries must be reduced all round and simultaneously by the parties concerned. Nuclear weapons must be banned. A general agreement must be reached on a suitable disarmament program, with an effective system of mutual control. In the words of Pope Pius XII: “The calamity of a world war, with the economic and social ruin and the moral excesses and dissolution that accompany it, must not on any account be permitted to engulf the human race for a third time.” (Cf. Pius XII’s broadcast message, Christmas 1941, AAS 34 (1942) 17, and Benedict XV’s exhortation to the rulers of the belligerent powers, August 1, 1917, AAS 9 (1917) 418)
113. Everyone, however, must realize that, unless this process of disarmament be thoroughgoing and complete, and reach (people’s) very souls, it is impossible to stop the arms race, or to reduce armaments, or—and this is the main thing—ultimately to abolish them entirely. Everyone must sincerely co-operate in the effort to banish fear and the anxious expectation of war from (people’s) minds. But this requires that the fundamental principles upon which peace is based in today’s world be replaced by an altogether different one, namely, the realization that true and lasting peace among nations cannot consist in the possession of an equal supply of armaments but only in mutual trust. And We are confident that this can be achieved, for it is a thing which not only is dictated by common sense, but is in itself most desirable and most fruitful of good.