The difference is Cuba was not making verbose threats to nuke the USA (or its territory). I know I was 8yrs old watching TV then when it was going down -- it was scary as fuck actually.
The threat was just implied -- what did President Kennedy do? Embargo Cuba and threaten Russian shipping into Cuba.
We could blow up the rail lines and bridges into North Korea. What are they going to do -- commit suicide and attack Seoul? If China and Russia will not intervene to maintain as least the status quo ... Then either they have no will nor balls or they are in acquiescence.
Tough shit you die!