Dictatorships on the other hand are terrified of their own people, and so crush and expression of freedom that they don't directly approve (see for instance the lady that was arrested in Moscow for standing in public with a blank piece of paper).
However in times of threat from an external force, then people group together and there's more cohesion. Would a democracy like France press the button to protect themselves or an ally under such circumstances? Yes, I think they would.
However these societies are not run by a single small cell of egotistical leaders like feudal courts of old as current autocracies are. The question is more, would these deranged autocracies have the dumb courage to risk annihilation by directly attacking the democracies they hate? Doubt it.