North Korea's Leader Views Missiles as Bargaining Chips

So what do you do with a guy who has a limp missile that he uses to get the world's attention? You call on China.

Slate: Nukes and missiles are the only bargaining chips that Kim possesses; his brutal regime and self-imposed isolation have kept the country impoverished. However, every time the larger powers bellow about the North Korean threat or seek to impose penalties through harsh U.N. resolutions, they play into his game—they lavish him with the attention that he needs both to negotiate for goodies diplomatically and to justify his totalitarian reign at home.
This is why it's so tempting to ignore Kim's games—but also why it might be dangerous to do so. He requires the "drama and catastrophe"; his regime would probably collapse without them. And so, if the United States and the other major powers paid no attention to, say, his missile test, he would raise the stakes, do something more outrageous, then raise the ante on that as well, until we did pay attention—until we had to.
In this sense, tangling with North Korea is like playing highway chicken with a wild but calculating kid who visibly throws his steering wheel out the window, forcing the other, more responsible driver to veer off the road.
China is the one country that could crack the rod. Nearly all North Korea's trade comes through China, which also supplies Pyongyang with a great deal of aid and investment. Yet Beijing's leaders are so expansive with their largess, and so lax in their discipline, because they know—and Kim knows that they know—that if Kim's regime begins to collapse, tens of millions of North Koreans will rush across the Chinese border, creating a humanitarian crisis beyond Beijing's resources and possibly destabilizing that corner of China as well.