Even though it is the ultimate in Type I Deterrence, the Doomsday Machine is an unsatisfactory basis for a weapon system. It is most improbable that … - Herman Kahn

The Doomsday Machine is not sufficiently controllable. Even though it maximizes the probability that deterrence will work (including minimizing the probability of accidents or miscalculations), it is totally unsatisfactory. One must still examine the consequences of a failure. In this case a failure kills too many people and kills them too automatically. There is no chance of human intervention, control, and final decision.And even if we give up the computer and make the Doomsday Machine reliably controllable by the decision makers, it is still not controllable enough. Neither NATO nor the United States, and possibly not even the Soviet Union, would be willing to spend billions of dollars to give a few individuals this particular kind of life and death power over the entire world.

We must not look too dangerous to neutrals. While this is probably less important for us than not looking too dangerous to friends and allies, it is still too important to be ignored. Here again, we must not look excessively destructive. It may be all right to promise the Soviets that if they attack us we will destroy every Soviet citizen in retaliation (though personally I think this far too destructive a proposal), but we should not threaten nonbelligerents with near annihilation because of our quarrel with the Russians. Many of the world's inhabitant perhaps two-thirds of them, do not feel it is their quarrel but feel it is their world. The more destructive we look, the less they like us and our program. To the extent that some in our midst talk and threaten potential world annihilation as a U.S. defense measure, we focus undeserved attention on ourselves as being dangerous and even irresponsible—appearing to be willing to risk uncounted hundreds of millions or billions of bystanders as to our selfish ambitions and desires. Neutrals and bystanders will inevitably suffer heavily in any thermonuclear War. But there is a difference between damage and annihilation.

In any case, the thought of a catastrophe or holocaust unleashed by accidental (i.e. nonhistorical) causes might be very unsettling to any Marxists who had a passionate belief in a deterministic theory of history. Instead of saying "It is inevitable that we will take over the world in fifty years", this Marxist would have to add, "Always assuming some capitalist fool doesn't press the button."