China has the ability to cripple North Korea by cutting off shipments of food, fuel, and luxury goods that Kim Jong Il doles out to loyalists. Kim’s nuclear detonation may put that leverage in play and test its impact on the leadership.
China is increasingly frustrated by North Korea’s defiance of United Nations resolutions designed to curb its atomic and missile programs and is concerned that a nuclear-armed government in Pyongyang could spark a new arms race in Asia, analysts and a person familiar with the Obama administration’s policy said.