All you list are except Cuba already are nuclear powers, itś too late. Kennedy in the cuba missile crisis agreed to never invade Cuba if Russia removed their missiles. That agreement still stands with Cuba and Russia. If Cuba in any way pursues nukes, invasion is guaranteed.
In no case has any country seeking nukes been a theocracy whose religious beliefs support a nuclear war as a way to bring in their theological new world. Further, as far as I recall, none has repeated endlessly for 40 years the aim of totally destroying another country.
Pakistan, the Muslim nuclear power, is a Sunni country, not at all the same as Shia.
It is a massive mistake to view Iranś religious government as rational by our standards, or as viewing the world and beyond as we do.
I suspect that Russia might try to station nuclear weapons
in Cuba as a result of our efforts in eastern Europe.
What evidence is there that Iran would use nuclear warfare
to the ends you claim?
Do you think we should take military action to stop N Korea
from developing platforms for their nukes?
To brand countries as rational or irrational is an illusion.
Those traits are both present in all countries.
Certainly, Ameristan behaves irrationally often.
Looking at the differences between Sunni & Shia....
Key Differences Between Shia and Sunni Muslims
...& also at how both have behaved, I'm not inclined
to say that one is safe relative to the other.