North Korea has been a problem child in the world-at-large for longer than most of the world has been alive. The DMZ is one of the largest permanent military operations in the world, and every act made by the nation is scrutinized thoroughly and treated with the utmost suspicion. A sort of prejudice against any action taken by N. Korea has formed in the world consciousness.
Tomorrow, Kim-Jong Al* usurps Kim-Jong Un in a violent takeover because he's sick of seeing his people in a famine state, he's sick of his people being denigrated, and he's sick of constantly wondering if eagleland will get sick of his nations antics and use nuclear weapons to make South Korea an island; but most of all, he's sick of the embargo that keeps him from upgrading from iPhone 6 to the iPhone 6s.
Given the current hostility towards anything North Korean, what would he have to do, and what would the world have to do, in order to bring North Korea gracefully into the world economy? At this point it seems like the mistrust would run too deep to gracefully let the nation become a world player.
*A fictional "Second Prince" to Kim-Jong Un if you will