Doesn't matter, if nobody interfers with Iran or N Korea nothing will happen. You know that Germany basically gifted submarines (U-Boat) that can fire nuclear "explosive devices" to Israel, a country which didn't sign the nuclear contract, like the US, Russia, Germany etc. did, and nobody cares about them. Experts say that Israel may have 200-300 nuclear "explosive devices".
Nowadays nuclear weapons are used as a "shield" nobody attacks with them, but everybody that has them is like: "well, if you try to F*** with us we might nuke you"
If I'm right the last nuclear thing used to harm anyone were those nuclear bullets in Vietnam, that didn't just kill the enemy but also the ones that were firing them.
Even the most retarded person must have realized by now that Nuking is fatal for everyone, when Tschernobyl blew up you weren't able to eat mushrooms found in the forest over at Germany, even 20 years later.
Nukes are pretty much a "Last Stand" Weapon. As long as you don't interfere with the countries that have them you don't have to fear anything.