And it evolved out of paranoia--Soviet paranoia that we wanted to exterminate them, and Western paranoia about the threat of global communism. Both sides were operating from a position of institutitonal insanity.
That said, just because you're paranoid, it doesn't mean they aren't out to get you.
Nevertheless, it was a really quite perilous situation, because the balance was dynamic rather than static. I'm not sure the Doctor Strangelove scenario was ever a real peril, but all it would take is one permutation of that and the wrong set of cascading errors in response.
We are all very lucky.
Mark Schynert