This is a two-year-old article but it's pretty interesting to read: "North Korea After Kim Jong Il: Four Scenarios" http://www.nps.edu/Academics/centers/ccc/publications/Online...
Think of them like a crazy family member that keeps in trouble unless people pony up cash and you pretty much have their entire strategy in a nutshell.
As US News and World Report once commented, threatening the North Korean government with isolation was like threatening a drowning man with a life preserver.....
His son is about to achieve one of the last great overt dictatorships in the world.
I bet everything he is going to want to taste that power for a long time before he actually does something aggressive.
That is not to say he doesnt press his luck, make a strategic failure and gets attacked (e.g. not accepting a rothschild-backed central bank)