Herman Kahn

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.

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.

World War I broke out largely because of an arms race, and World War II because of the lack of an arms race.

You are a big country now but you still tend to feel small and fragile. If the United States gets a cold you get pneumonia.