The past two days have been somewhat different from other days with regard to the spiraling tit-for-tat actions raising tensions in Northeast Asia, which now worryingly seem to be taken for granted to some extent.

On Monday, the Democratic People's Republic of Korea fired four, maybe five, ballistic missiles toward the Sea of Japan in protest against the ongoing military drills being staged by the United States and the Republic of Korea, which it has condemned as a rehearsal for an invasion.

And the first of 14 US C-130J Super Hercules military airlifters, its "meanest, toughest, most tactical machine", arrived in western Tokyo in a show of strong commitment to its ally, whose leader asserted the DPRK missiles were a "new stage of threat".

Then on Tuesday, Washington and Seoul showcased the arrival of key components of the US' Terminal High Altitude Area Defense anti-missile system in the ROK.

Though seemingly in a rush, the US and the ROK have taken the first step toward a crossing of the Rubicon, shifting the multi-stakeholder security impasse in Northeast Asia toward a conflicting path and bringing the prospect of a mini "cold war" in the region, even a hot war, closer to being a self-fulfilling prophecy.

As the stated target of THAAD, the tough-talking DPRK is likely to counter the mounting threat with acceleration of missile programs, continuing to offer Washington, Tokyo and Seoul excuses to boost their war-preparedness and deploy similar systems at more locations on China's periphery.

Although the US and the ROK contend that THAAD's perceived potential threat to Chinese security is collateral and unintended, protests of Chinese consumers against ROK companies facilitating the THAAD system have demonstrated their concerns about it being a real security challenge that should be met.

The deployment of THAAD undermines strategic and security interests of countries in the region, including China and Russia.

And as many have observed, the proclaimed security benefits THAAD brings to the ROK will prove negligible compared with the losses it incurs. Since Seoul's miscalculation has already borne its bitter fruit, the immediate priority, for all stakeholders, is to prevent things from spiraling out of control.

THAAD's deployment in the ROK will only harm efforts to peacefully realize stability on the Korean Peninsula. The recent past possibility of Beijing and Moscow joining with Seoul, Washington and Tokyo to discourage Pyongyang may hardly be possible with THAAD getting in the way.

Given the professed shared interest of Washington and Seoul in a non-nuclear Korean Peninsula, as well as the painful fact that their joint military drills have spurred Pyongyang to speed up its missile program, they should call off the deployment, avoid traveling further down the wrong path, and act constructively to promote peace in the region.