"So we have a challenge of optimizing our capability in a completely new environment. Space has intruded, you might say, in many ways, and in other ways it can bring about what I consider a spread in our deterrent overall capability. We can deter by—deterrence requires the deterrer to have the credibility that what he has is something that an enemy can't really do anything but, in the end, lose. Then he's deterred. But if he doesn't, for any reason at all, believe that we can do it, then deterrence flies right out the window."