Republic of Korea President Moon Jae-in's four-day state visit to China that begins on Wednesday is certainly another sign that there has been a thaw in the recently chilly China-ROK relationship.

But pleasant as it will no doubt be to the ears of his hosts, his promise not to use the Terminal High-Altitude Area Defense anti-missile system for purposes other than preventing nuclear/missile threats from Pyongyang, will be difficult to verify in practice.

Nor will his appeal for the two sides to view the matter from each other's perspective mitigate Beijing's worries about THAAD's potential threat to national security.

Seoul should not assume Beijing will simply drop the matter just because its deployment in the ROK is now a fait accompli. It should honor the pledges it has made to Beijing.

However, although a complete thawing of relations may be a long and difficult process with THAAD in the way, Moon's attempt to assuage Chinese concerns does offer a starting point for repairing relations.

And it is essential both parties are pragmatic. They need to show a shared sense of urgency in working together on the imperative task of defusing the dangerous time-bomb ticking on the Korean Peninsula.

Although Beijing and Seoul both oppose the military option, they have yet to sit down and talk about what non-military alternatives are available, and feasible.

And though Moon has on multiple occasions expressed opposition to any military strike as an option for dealing with the Democratic People's Republic of Korea, his government has displayed little hesitancy in joining the United States' tit-for-tat saber-rattling when responding to Pyongyang's provocations.
If Pyongyang's missile test on Nov 29 and the US-ROK joint drill that followed were any indication, neither side seems ready to embrace the "dual suspension" proposal that Beijing and Moscow have long stood by. Nor is there any sign that the Six-Party Talks can be resumed any time soon. On the contrary, there has been growing pessimism about the possibility of a political resolution after a United Nations envoy returned from Pyongyang.

President Moon's visit presents a precious opportunity for China and the ROK to engage in serious discussion about how to engage Pyongyang and Washington in pursuit of a peaceful end to the crisis.