The widespread diffusion of nuclear weapons would make many nations able, and in some cases also create the pressure, to aggravate an on-going crisis, or even touch off a war between two other powers for purposes of their own.
For some years I have spent my time on exactly these questions - both in thinking about ways to prevent war, and in thinking about how to fight, survive, and terminate a war, should it occur.
From a scientific perspective there is some indication that a nuclear war could deplete the earth's ozone layer or, less likely, could bring on a new Ice Age - but there is no suggestion that either the created order or mankind would be destroyed in the process.
Projecting a persuasive image of a desirable and practical future is extremely important to high morale, to dynamism, to consensus, and in general to help the wheels of society turn smoothly.
Because of new technologies, new wealth, new conditions of domestic life and of international relations, unprecedented criteria and issues are coming up for national decision.
Deterrence itself is not a preeminent value; the primary values are safety and morality.
