For most of Kim Jong Il’s reign in North Korea, relations between China and his isolated country have alternated between extreme suspicion and a grudging politeness based on mutual need. The most intensive diplomacy between North Korea and China has taken place since Mr. Kim began to use his nuclear card two years ago. Now, as Kim agrees to rejoin the six-party talks in Beijing this month to discuss eliminating his nuclear-weapons program, many experts say that relations between the two states are ever more important. Full Story