The Russian "Dead Hand" System works on the belief that even if the USA succeeds in destroying all the command and control structures of the Soviet Union, the system is to be organised so that the retalitory strike will be launched if contact with command is broken. Which basically means that the Soviets (and their Russian sucessors) will launch a strike on the USA unless they tell it NOT to!
The potenial for a catastrophic apocalypse is overwhelming, especially if you consider that eventually there could be a natural disaster or planetary destructive event that would be crippling enough without the threat of nukes being unleashed.
Think about that and try to sleep tonight... good luck!
To see how the Russian "Dead Hand" System works in detail, download pdf file here