File photo shows Seoungju residents chant slogans during a protest against the government's decision on deploying a US THAAD anti-missile defense unit in Seongju, in Seoul, South Korea, July 21, 2016. The banner reads "Desperately oppose deploying THAAD". [Photo/Agencies]

With Washington determined to rush its Terminal High Altitude Area Defense anti-missile system to the Republic of Korea "as soon as possible", the matter looks more than ever like a "done deal". Which Daniel Russel, United States under-secretary of state for East Asia, said already is.

The costs and benefits of the highly controversial, divisive deployment for all parties concerned have become obvious through tense, intensive prior discourse.

While gaining the illusive sense of security from THAAD, Seoul will face an angrier, unbridled Pyongyang and greater threat from the north, lasting grudge from Beijing and even Moscow, which find their security interests compromised.

Washington may find Seoul bound more tightly to its bandwagon on its Northeast Asia chessboard, but will see China and Russia less cooperative on key regional and global issues.

It is obvious that Washington and Seoul have ignored the strong opposition from Beijing and Moscow to the THAAD deployment on the Korean Peninsula as the system far exceeds the ROK's actual defense needs.

And since Seoul and Washington stubbornly proceed with THAAD's deployment, an almost definitive all-lose game, no reasoning or arguing may suffice to deter them.

Beijing, given this fact, should be realistic and stop fancying THAAD's deployment can be prevented in the current situation on the Korean Peninsula. As THAAD is posing a substantial security threat, now is time to refocus－rid itself of the helpless war of words, concentrate instead on effective countermeasures.

A sane approach is critical here, as without cool-headed, all-round evaluation of what degree of threat THAAD constitutes, subsequent response may end up being inadequate or excessive.

Of course, Seoul deserves to pay a price for an act that undermines a key Chinese national interest. But it takes a lot of weighing and balancing to come up with sensible, targeted, well-tailored countermoves.

This is not just about China-ROK relations, whose failure may not be crippling for either side. Nor is it about treating Seoul as a less-than-considerate neighbor, or a rival's proxy. It is more about how Northeast Asia defines security relations in the region, the consequences of which will be felt for many years to come.

If every country in the region goes its own way, the already difficult processes of regional integration will be at stake.

In a narrower sense, they are at a make-or-break moment on denuclearization of the Korean Peninsula. If they continue perpetuating the current state of hopelessness, they will only raise the stakes higher.