Cuba Missle Crisis: In 1962 the stationing of Russian nuclear war heads in Cuba brought the world to the brink of a, possibly nuclear, war between the two super powers. The intense decision making process is documented in transcripts of discussions that were secretly taped in the White House (The Kennedy Files)

Movie: Thirteen Days (2000), with Kevin Costner, Bruce Greenwood

Text of the Letters exchanged between Nikita Khrushchev and John F. Kennedy from 1961-1963. Especially interesting are documents #65 to #70, written in the heart of the crisis.

I found the following passage by Khrushchev most impressive:

"Mr. President, I appeal to you to weigh well what the aggressive, piratical actions, which you have declared the USA intends to carry out in international waters, would lead to. You yourself know that any sensible man simply cannot agree with this, cannot recognize your right to such actions.

If you did this as the first step towards the unleashing of war, well then, it is evident that nothing else is left to us but to accept this challenge of yours. If, however, you have not lost your self-control and sensibly conceive what this might lead to, then, Mr. President, we and you ought not now to pull on the ends of the rope in which you have tied the knot of war, because the more the two of us pull, the tighter that knot will be tied. And a moment may come when that knot will be tied so tight that even he who tied it will not have the strength to untie it, and then it will be necessary to cut that knot, and what that would mean is not for me to explain to you, because you yourself understand perfectly of what terrible forces our countries dispose.

Consequently, if there is no intention to tighten that knot and thereby to doom the world to the catastrophe of thermonuclear war, then let us not only relax the forces pulling on the ends of the rope, let us take measures to untie that knot. We are ready for this." (Telegram From the Embassy in the Soviet Union to the Department of State, Moscow, October 26, 1962, 7 p.m.)

Other Links: Cuba Missle Crisis:
Wikipedia
Time Line
National Security Agenecy (NSA)
National Security Archive