nuclear issue. I used it way back in 1939 as the rationale for starting the work on the atom bomb (but soon realized its fallacy); it was the rationale for nearly all the scientists in the pre-Manhattan years. Deterrence - in its various forms - was the reason for the build-up of huge arsenals during the Cold War period, and it is being used now to justify the retention of nuclear weapons.
The problem of deterrence has of course been frequently debated in Pugwash, as well as in numerous other forums. But the arguments have usually been on the political, strategic or military aspects; little attention has been paid to the ethical aspect. The reason for this is the one mentioned earlier: ethical issues have no place on the agenda of the cynics. But for Pugwash the ethical dimension of deterrence should be of prime importance. If the use of nuclear weapons is a crime against humanity, how can the threat of their use ever be justified?
In discussing the problem of deterrence I am primarily concerned with the doctrine of extended deterrence, although the ethical element applies of course to all aspects of deterrence. The argument that nuclear weapons are needed to prevent any aggression is the chief reason for policies of indefinite retention of nuclear weapons. I believe that if this argument were shown, and accepted, to be invalid it would open the way to the total elimination of nuclear weapons.
The extended deterrence argument lacks credibility, largely arising from the general abhorrence of nuclear weapons. The existence of these weapons has not prevented the several hundred wars that have taken place since 1945. Nor has the possession of them prevented the USA and the Soviet Union from being defeated (in Vietnam and Afghanistan). No doubt, there were political and military reasons for the non-use in these cases, but the opprobrium associated with such use must have played a significant role. The taboo against the use of nuclear weapons is still strong and this weakens the threat of deterrence. On the other hand, if the taboo is too strong the deterrence argument would cease to be valid. The whole thing is based on a deliberate ambiguity. We have made our security hang on uncertainty: on whether or not a would-be aggressor will take the threat seriously.
The deterrent would be effective only if it is made absolutely clear that the threat will be converted into action; otherwise it would have no value and the bluff would be called. This means that George W. Bush, or Tony Blair, have to show convincingly that they will push the button and unleash the most destructive and omnipotent weapon in a dispute which could otherwise be solved with much less destruction. The threat may work for a time but eventually an aggressor will gamble on the uncertainty. In the meantime, the security of the world is based on a balance of terror, and as Francesco Calogero pointed out a long time ago: "The fact that the survival of human civilization is predicated on such a policy may, in the long run, result in the disintegration of the ethical basis of civilized society."
Although the ethical aspect of nuclear deterrence is as old as nuclear weapons themselves, there are valid reasons for raising it now as an item for our agenda. There is growing awareness in the world community about individual and collective responsibility for one's deeds. With the establishment of the International Criminal Court, people may be put on trial for offences against international law even if these are legal under national laws.
This raises the much wider issue of the personal responsibilities of scientists working on military projects. If the use of a given type of weapon is illegal under international law, should not research on such weapons also be illegal, and should not the scientists also be culpable? And if there is doubt even about the legal side, should not the ethical aspect become even more compelling? In this connection we should be reminded of the call issued in 1995, on the occasion of the 50th anniversary of Hiroshima, by Hans Bethe, the most senior scientist in this field:
I call on all scientists in all countries to cease and desist from work creating, developing, improving and manufacturing further nuclear weapons - and, for that matter - other weapons of potential mass destruction such as chemical and biological weapons.