It's a scary situation, that's for sure.  However, too often overlooked is the likelihood that both both Cuba then and North Korea now were/are acting defensively.  

I'm not aware that North Korea has developed its weapons with a view to invading any of its neighbours.

And most people forget that the attempt to put nuclear weapons in Cuba came just 18 months after a failed American-backed invasion attempt at Bay of Pigs.  Of course it was defensive.