China and South Korea accuse each other of undermining key national principles

China and South Korea have exchanged formal protests over the highly sensitive Taiwan question and Korean unity. The two countries have been trying to improve relations in recent months, but South Korean national security adviser Wi Sung-lac said he had issued “a serious objection” after an official Chinese statement welcomed moves “towards the peaceful coexistence of the two states of South and North Korea”. Meanwhile, Beijing “lodged serious representations” with Seoul over an art event…