Oh that's very simple. Why? Because the North Koreans are a cult worshipping one family and man through military might dictatorship.
Iran is a death worshipping cult who has become hellbent on ushering in the coming of the Imam Mehdi through the spilling of the blood of the infidels via jihad. They manipulate the self flagellating sinners into bypassing the normal method of redemption through their religion into believing jihad is the only way to achieve martyrdom into Heaven. So that when the Ayatollah does spill enough blood of the infidels and cause the Twelfth Imam to appear and usher in the end of the days, the dead will rejoin the living and face judgement. Those who died during the course of Jihad will then inherit the New World. Or, I'm not Muslim so maybe I'm wrong, and the Ayatollah himself is preaching that he's the Twelfth Imam and is preparing to usher in the Anti-Christ and the return of Prophet Isa his God damned self. They have no problem spilling the blood of innocents to do this because it's irrelevant to them because the dead are meant to rejoin the living and face judgement together at the end of their jihad anyway. He has promised this to his people and followers though, just like the previous Ayatollah.
Either way, yeah kind of a big fucking difference.