The China getting upset on THAAD deployment is understandable. It will jeopardize their nuclear retaliation capability with ICBM. And the superior capability of THAAD radar is also quite uncomfortable for China.
But China didn't do its homework. NK is essentially vassal state of China. China is responsible of bad behavior of NK. North Korea is threatening US with WMD like nuclear bomb and ICBM/SLBM missile. China has enough influence and power to inhibit NK from playing nuclear game against USA. But China didn't any substantial effort to keep NK from developing WMD. So US/SK is deploying THAAD in Korea to defend such threat of WMD of NK.
If China is to object THAAD deployment, it should do its homework. Cut all the economic and political/military tie with NK. Force NK to abandon its WMD development efforts. then SK/US has no need of THAAD.
It is simple: No Chinese money to NK, No WMD in NK, No THAAD in SK.
