Kahn vs. Failsafe

Kahn came up with the thought of the practical politics of a Doomsday Machine -- a computer attached to a cache of thermonuclear weapons which could automatically trigger in the event of a nuclear attack and purposely coat the planet in nuclear fallout. Building such a weapon would be, in Kahn's mind, impractical, dangerous, and foolish, but he used the idea as an analogy to the state of Europe at the time.
This more relates to Dr. Strangelove where the U.S. bombed Russia and set off the Doomsday Machine but since Fail-Safe and Strangelove are so similiar it can be assuemed that Kahn is reffering to this sence of "second attack" or retaliation. Thats all that the Doomsday Machine does. It prevents them from being bombed because the people bombing them know the consequesces if they do. However this machine does no good if no one knows about it because then it doesnt provide fear, it just kills everyone.