I don't like the word nuclear exchange, it's like an exchange of wheat and so on. It's a horrible term and I always cross it out when I see it somewhere.
I'm not a representative of the military establishment. I came in with the Reagan Administration in 1981 as a presidential appointee.
The Soviets are not just looking at Moscow, they have a very extensive program of not only research, development, they have built this radar net around the whole country. One of those radars has become infamous because it's a clear violation of the ABM Treaty. They have an infrastructure and they are well prepared to develop a nationwide defensive system.
I think the important point is the turning point in combining offense and defense in a reasonable way.