There's a good chunk of people in this topic who are loving stupid. I won't list names. (pat yourself on the back now.)
North Korea is likely to topple over itself before it presents a real threat. Believe it or not, the propaganda machine in North Korea is not as good as you're led to believe. Black markets in NK flood the country with western media, albeit privately. Plenty of them know their country is stuff and they live in a hell-hole, but what can ordinary people do about it when their families and themselves are threatened with forced labor, death, and knowing that whoever pulls the trigger is going to get an award for doing that. It's a loop of people backstabbing each other to benefit themselves, which is only natural given your circumstances.
When it does topple, the real threat will come from China.