Residents chant slogans during a protest against government's decision on deploying a US THAAD anti-missile defense unit in Seongju, Republic of Korea (ROK), July 13, 2016. The banner reads "Desperately oppose deploying THAAD in Seongju". [Photo/VCG]

What has historically been ours is ours. Even if others say it is not. That is why, annoying as it is, the Philippines-initiated South China Sea arbitration is actually not worth the limelight it is being given.

It is time for Beijing to get down to real, serious business. It has bigger issues to attend to, the most imperative of which is the anti-missile system being deployed on its doorsteps. Because, while it was coping with the worthless arbitral award from The Hague, Washington and Seoul finalized their plan for the deployment of the US' Terminal High Altitude Area Defense missile system in the Republic of Korea.

The arbitral ruling, which is null and non-executable, will have little effect on China's interests and security in the South China Sea. But not THAAD, which is a clear, present, substantive threat to China's security interests.

The installment of the US system in the ROK should be of far greater concern to Beijing, and warrants a far stronger reaction. Or should we say retaliation?

The ROK has legitimate security concerns, especially with Pyongyang constantly threatening nuclear bombing. With that in mind, Beijing has been adamant about de-nuclearization of the Korean Peninsula, and worked closely with Seoul and Washington in implementing and upgrading United Nations sanctions, and appealed tirelessly for restarting the Six-Party Talks.

But Seoul has brushed aside Beijing's security interests while pursuing those of its own.

Washington and Seoul did claim that THAAD would be focused "solely" on nuclear/missile threats from the Democratic People's Republic of Korea, and would not be directed toward any third-party nation. But THAAD far exceeds such a need. Besides the far more credible threat from Pyongyang's artillery, short-range and lower-altitude missiles is simply beyond the system's reach.

While it will deliver a limited security guarantee to the ROK, THAAD's X-band radar will substantially compromise the security interests of China and Russia, no matter how the United States shrouds its purpose.

Yet having made such a beggar-thy-neighbor choice, Seoul has in effect turned its back on China. By hosting THAAD, it has presented itself as Washington's cat's-paw in the latter's strategic containment of China. All rhetoric about friendship is meaningless lip service with the deployment of THAAD.

Beijing must review and readjust its Korean Peninsula strategies in accordance with the latest threat from the peninsula, including its ROK policies.

That does not mean forsaking its commitment to de-nuclearization, or UN resolutions. But Beijing must concentrate more on safeguarding its own interests, both immediate and long-term.