N Kor comes late to the nuclear game. While N Kor was the site of the Japanese nuclear program during WW II, the effort lay dormant for a long time afterwards. They were first, but they are also last. They may not be aware that nukes cannot be used to blackmail other nuclear powers. Same for Iran. It will not be allowed.
""They may not be aware that nukes cannot be used to blackmail other nuclear powers""
Err,what exactly did the Pakis do when India threaten to attack them twice in 2002(for terrorist acts in India)-but I must add that one is a Islamic dictatorship & the other is a secular democracy- so u can only expect rational behaviour from one.