North Korea is a sticky situation, it has been the "Elephant in the room" for a long time. Sanctions seem to have no effect, because China(and probably Russia) trades with them anyway. Sanctions seem to only help wipe out their citizens to starvation, fat ass still eats plenty.
If we wait too long to deal with them, they're going to get better and better weapons. Since we sanctioned them to hell, they'll probably sell them off to other countries. Countries that are even more unstable than North Korea.
If we attack them, who knows what they might do to South Korea, Japan, and perhaps Guam or Hawaii. If we did take them over, South Korea doesn't want 20+ million refugees, esp after Seoul got attacked. Can North Koreans even integrate? All that brain washing over the years.
But ya, something has to be done sooner or later, because North Korea can cause a lot of damage, and the more we wait, the more damage they can cause. It's just we dunno how to handle it.
Personally, I blame this mainly on China. They know what it going on in NK, they knew how shitty they treated their own people, yet they ignored it all. They allowed them to get nukes, and never put their foot down. They could have put an end to this ages ago, they're NK's bread and butter.