I have been surprised at the unanimity with which the notion of the unacceptability of a Doomsday Machine is greeted. I used to be wary of discussing… - Herman Kahn

Here is another form of deterrence which, while not a Doomsday Machine, is still an"ultimate" of a sort. This could be called the Homicide Pact Machine, an attempt to make a failure of Type I Deterrence mean automatic mutual homicide. The adherents to this somewhat more practical device hope to divide the work of deterrence in a natural way: We destroy the enemy and the enemy destroys us, neither of us cheating by buying any effective Counterforce as Insurance for our respective societies. The Homicide Pact Machine is clearly more satisfactory to both humanitarians and neutrals than the Doomsday Machine and both should make the distinction.

Even if military advantages were not to be had by deliberately limiting attack to counterforce targets, I suspect that most governments would still prefer to observe such limits. Almost nobody wants to go down in history as the first man to kill 100,000 people.

However, even those who expect deterrence to work might hesitate at introducing a new weapon system that increased the reliability of deterrence, but at the cost of increasing the possible casualties by a factor of 10, that is, there would then be one or two billion hostages at risk if their expectations fail. Neither the 180 million Americans nor even the half billion people in the NATO alliance should or would be willing to design and procure a security system in which a malfunction or failure would cause the death of one or two billion people. If the choice were made explicit, the United States or NATO would seriously consider "lower quality" systems; i.e.,systems which were less deterring, but whose consequences were less catastrophic if deterrence failed. They would even consider such possibilities as a dangerous degree of partial or complete unilateral disarmament, if there were no other acceptable postures. The West might be willing to procure a military system which, if used in a totally irrational and unrealistic way, could cause such damage, but only if all of the normal or practically conceivable abnormal ways of operating the system would not do anything like the hypothesized damage. On the other hand, we would not let the Soviets cynically blackmail us into accommodation by a threat on their part to build a Doomsday Machine, even though we would not consciously build a strategic system which inevitably forced the Soviets to build a Doomsday Machine in self-defense.