watched many NK movies documentaries (like series made by vice.com) and i think US just doesn't want to kill those people. imagine 2-3 million of brainwashed NK soldiers, sure US have capability to erase them with few strikes but i think even agressive country like US doesn't want to have so many souls on their account
i think they (russia, china, US) will be just waiting for some domestic civil war maybe support them quietly and let north koreans take care of their regime but from what i've seen i have no idea how this could be achieved - everything is so hard under kim kontrols there.
don't know where it all leads and how it ends, but i doubt kim's missiles will reach anything i think russia and china will take it down after launch if it pose serious threat really, what was interesting in this article was this nuclear strike from satellite to shut down electricity grid by EMP - didn't know it's possible but sounds logical.