Protesters hold a rally against the deployment of the US missile defense system in Seoul on Saturday.Yao Qilin / Xinhua

Thursday marks the 25th anniversary of diplomatic relations between China and the Republic of Korea, an occasion that should have been observed with lots of fanfare and the extending of mutual best wishes.

That such high-profile celebrations are conspicuous by their absence can be attributed to the deployment of the United States' Terminal High Altitude Area Defense anti-missile system in the ROK, which put a brake on the development of the hard-won strategic cooperative partnership, and then thrust it into reverse.

Despite Beijing's firm opposition to the ROK's deployment of THAAD given its potential damage to the regional strategic balance and China's security interests－as well as the doubts about the system's ability to achieve its stated purpose of defending the ROK should it come under attack from the Democratic People's Republic of Korea－the recently installed ROK President Moon Jae-in ordered a speedy deployment of the controversial missile defense system late last month after the DPRK's most recent missile test.

The move dashed the hopes which arose when he took office in May that he would postpone the system's deployment in the ROK pending an environmental review. It was anticipated that this would improve the deteriorating Sino-ROK relations, by giving the two neighbors time to sort out their differences and find a common approach to easing the growing tensions in the region.

For relations shouldn't be like this. In the face of the escalating brinkmanship between the US and the DPRK, Beijing and Seoul are both on the same page in wanting the Korean Peninsula to be nuclear free, and both believe war is not an option. Just last week, Moon said he was considering sending a special envoy to the DPRK for talks in a bid to jump-start diplomacy.

The ROK's security concerns are genuine, but they would be better addressed by not estranging China, and the two countries working closely together to promote peace and stability on the peninsula.

The ROK should not let its fears that it is in the DPRK's cross hairs betray its judgment. Hanging on to the coattails of the US, which has its own aims in the region, merely increases the likelihood of those fears coming true.

Twenty-five years ago, the leaders of China and the ROK, guided by their wisdom, and displaying courage and vision, beat all odds and decades of hostility to forge a friendly relationship that has benefited the two nations tremendously and contributed to peace, security and prosperity in the region.

Seoul should display similar wisdom and vision now.