This chapter considers the relationship between nuclear deterrence and nuclear defense. The term nuclear defense sounds oxymoronic, and for most of the nuclear age, strategists, at least Western ones, have regarded it so. But the question of defense with or against nuclear weapons needs more careful consideration. New technologies prompt policy makers and military thinkers to speculate about new strategies. In addition, the mission or function of defense is one that can be accomplished with a variety of approaches. Nor is the relationship between offense and defense one that is dictated by technology, except in a very gross way. It is fundamentally a strategic relationship, influenced by technology but not determined by it.
The discussion reviews some of the hereditary components of U.S. nuclear strategy as it relates to the relationship between offensive and defensive missions. It will note the distinction between force structures uniquely tasked for nuclear retaliation and those in which conventional and nuclear missions can be commingled. The latter are the more problematical from the standpoint of command and control, the backbone of effective strategic implementation. Strategies and technologies that cannot be implemented, especially in crisis time or during war, are likely to be incredible as deterrents.
The last statement is partially qualified. A deterrent can be credible without being perfectly rational according to some strategist’s calculus of the nuclear force balance. As I note below, force balances are only part of the equation for deterrence stability and crisis management. Obviously one-sided force imbalances might tempt aggression, but this temptation is conditional upon providing for the aggressor some ability