This film is definitely satire at its best. The fact that it is still applicable about the World today, 60 years after it was filmed says it all.
Perhaps the most telling point of the whole film is with regards to the way that the unintended consequences of the attack order lead to such calamities. It is incredibly believable that one of the nuclear powers has a contingency plan that would result in a nuclear bomb being released that can't then be aborted, after all politicians tend not to think about the full consequences of their actions. Yes a final contingency might be necessary, but how can you guarantee that when the order is given will indeed be at the very end?
Some parts of the film are a little strange - particularly the pilot riding the nuclear weapon into the target - and perhaps the simplicity of the impending disaster maybe needs a little more suspense or a little more depth to really take you through the whole film. All in all though a worthwhile movie and probably meritorious of its position in the Top100.