North Korea is A Military Junta, South Korea is a Military Junta disguised as a "Republic"

 North Korea is not really ran by the Kim dynasty think about it. They have a huge military, military leaders were purged by Kim Jung Un when he took power. Why? Because the military has a presence in the politics in North Korea. Un has to work with the military and bribe them. Why? To appease the military in North Korea. The reason you see missile tests is because of the military not Kim Jung Un the real power is with the military. The North Korean military knows if they start war or spark a fight they will lose and would have to participate in a bloody conflict. The end result would be no North Korean military and war crime tribunals. The military is smart they're not going to put themselves in that situation. However, it takes one crazy General to spark things in Korea that is what you have to watch otherwise North Korea is just playing games to antagonize there rival the ROK army. Its like a football game between two bitter rivals I'm willing to bet a good portion of both militaries like the game they are playing but hope it will continue to be a game and not all out war.

To get elected in Korean politics you have to have support from the ROK army, if you don't you will lose, ROK army is embedded in South Korean politics. If you look at the past, people in power were former military generals you also see coup's throughout South Korea and if you think it will never happen again you're naïve. The ROK army can still overthrow and still can be a ruthless force to civilian opposition. Will it happen probably not, is there still that possibility absolutely.