Experts have long debated the idea of defending national territory against airborne strategic attack. These debates often conflate feasibility, morality, strategy, and politics, so that each observer must independently weigh such factors even in arguments that seem to be purely technical.

BMD (ballistic missile defense) supporters tend to draw on early strategic theory developed by Wohlstetter (1958) and others from the RAND Corporation (for example Kahn 1970). They generally suggest the following: Nuclear strategy is neither easy nor impossible. It requires repeated analysis and improvement. It should serve national policy, such as deterring enemies (or the nation should change its policy). National leaders have a commitment to preserve and protect the people and the political system as well as they can, which no technical advice can abrogate. Deterrent systems should maximize human control over weapons. Deterrence based on the threat of retaliation against civilians is immoral...