Even as they recently celebrated the 30th anniversary of bilateral ties, South Korea and China couldn’t avoid clashing over one of the major points of friction in their relationship.

Following a meeting between their top diplomats last month, China’s foreign ministry reiterated its support for the so-called three nos agreement, under which the previous Moon administration reportedly promised that Seoul would not install additional THAAD missile interceptors, not join a U.S.-led missile defense network and not enter into a trilateral alliance with Washington and Tokyo.