After the North Korean rocket launch, South Korea announced it would “officially discuss deploying Thaad to US Forces in Korea to improve its missile defense posture.”

Thaad stands for Terminal High Altitude Area Defense. It’s a US anti-missile system, similar to Patriot missile batteries but is able to work against ballistic missiles at a higher altitude. As the term “terminal” indicates, it’s supposed to take out ballistic missiles as they start to descend on their targets from on high.

There are reasons to be skeptical about Thaad’s utility to South Korea, and not just because missile defense appears to be mired in a difficult and unattractive adolescence.

US-made Thaad launcher

Thaad is unlikely to do the ROK much good in defending against North Korean missile attack because of the short distances/times/types of missiles involved.  According to this Arms Control Wonk podcast, (listen at 15:00) the system might provide some protection for the southern tip of the ROK against DPRK attack but not much else.

As to why Thaad? There is of course the issue of the People’s Republic of China, which is the only other country in the area that might fire missiles that the United States would want to intercept.  The PRC thinks so, too, and has made prompt, public representations to the ROK that this Thaad in South Korea is a bad idea.

The prevailing US attitude appears to be, F*ck ‘em. The PRC has been unacceptably laggard in pressuring the DPRK to knock it off, so as punishment they get US missile defense on their doorstep.

Thaad in the ROK is seen as potentially blunting the PRC’s “A2D2” or “anti-access/area denial” option of using its copious supply of short and medium range ballistic missiles to turn the waters around China into an ocean of flame for the US Navy in the case of a confrontation over Taiwan, the Senkakus, or whatever.

It’s hard to argue with a defensive measure that would help deter the PRC from military adventurism in the region. However, there’s another side to Thaad, one that supports the PRC objection in unexpected ways.

In terms of a Thaad facility in the ROK, Sukjoon Yoon described the capabilities of the system in The Diplomat:

Thaad’s range will extend beyond the Korean Peninsula. The coverage provided by the existing sea-based Aegis system will be greatly extended by the planned deployment of AN/TRY-2 radars. These track inbound short- and medium-range ballistic missiles (SRBMs and MRBMs) with a high-resolution X-band (8-12.4 GHz) phased-array sensor system providing a 120-degree azimuth field out to 1,0003,000km, effectively covering the whole of mainland China.

And there’s this.

Like Turkey, the ROK has considered its own homegrown missile defense project, which the United States deplores because it would be stand-alone and just protect the ROK. Signing onto Thaad isn’t pursuing “missile defense.” It’s “providing a platform for the US integrated missile defense system.”

Per Yoon:

The deployment would imply that South Korea is part of the Ballistic Missile Defense (BMD) led by the US Missile Defense Agency. South Korea is also developing an indigenous missile defense system against North Korean threats, the Korea Air Missile Defense (KAMD) system, which is less likely to antagonize China than Thaad, since it will not be integrated into the wider BMD system designed to counter Iran in Europe and China in the Asia-Pacific.

What has particularly disturbed the Chinese military is the prospect of the U.S. linking individual sensors, interceptors, and communications assets dispersed all around the Asia-Pacific region into a comprehensive and integrated BMD system to interdict Chinese ballistic missiles in the boost and ascent phases of their trajectories. This would allow Thaad to penetrate and severely compromise China’s air defense zone.

And there’s more. With the military, there’s always more.

There is Thaad, you see, and then there is THAAD-ER.  THAAD-ER is currently just a gleam in Lockheed Martin’s eye ($30 million in declared LM outlay on top of $2 million seed money from the Pentagon), but it is easy to believe it will be welcomed into the US Missile Defense Agency’s $100 billion portfolio of anti-missile capabilities.

ER stands for “extended range.” Its publicly announced mission is to counter the threat from hypersonic glide vehicles currently being developed by the PRC and the Russian Federation.  Hypersonic glide vehicles, you see, have the ability to scootch along on flatter downward trajectories than the simple upsy-downsy parabolas of pure ballistic missiles while chugging along at speeds of 8-10 Mach. The HGVs are also designed to operate in the tricky boundary between the atmosphere and space, where neither  space rocketry or aerodynamic correction work very well in missile defense. THAAD-ER is supposed to handle that.

Per Lockheed Martin:

“That kind of a target is designed to find a seam between systems like Patriot … and systems like the Aegis weapon system. Because Thaad operates both in the endoatmosphere and the exoatmosphere, it has intercept capability in the region where that threat flies. The extended range version [of Thaad] would extend our battlespace against that kind of threat.” 

That means the target has to be acquired and attacked further out i.e. extending the range by adding a booster rocket. The booster also gives the Thaad missile some linger, diddle, and fiddle leeway to adjust the flight path to hit a hypersonic glide vehicle.

And there’s potentially more involved than the A2D2 equation.

“With an additional stage and an ability to loiter, Thaad [extended range] has been reported to have nine to 12 times existing Thaad coverage, and its increased velocity could potentially both counter hypersonic threats and have homeland missile defense applications, supplementing [Ground-Based Midcourse Defense],” said Thomas Karako, an analyst with the Center for Strategic and International Studies.

Not sure if he’s talking square kilometer or linear distance coverage. The current Thaad missiles have a range of 200 km.

In any case, the “Ground-Based Midcourse Defense” that THAAD-ER is supposed to supplement is anti-ICBM defense. The PRC has noticed Thaad’s implications for its strategic nuclear missile deterrent and is not pleased, per CSIS think tankers:

Chinese officials argue that Thaad could be used to monitor Chinese launches potentially as far inland as Xi’an in northwest China and could be linked to the larger US ballistic missile defense (BMD) system to undermine China’s “lean and effective” second strike capability.

PRC planners are probably not persuaded by wonkish poor mouthing that Thaad is a hopeless boondoggle suffering from the same case of blind staggers that seems to afflict the Star Wars program overall, and unconvinced by assertions Thaad in South Korea will never impact PRC’s strategic nuclear deterrent.

The US, I suspect, is carefully sandbagging its strategic ambitions for the Thaad so they can spot them around the PRC and Russia in the name of local defense. Once the missiles are in there, they’ll be integrated into the region-wide network and can be upgraded to strategic assets to the extent that technology and diplomacy and the ability to fudge field tests as needed allow. Money, I think it is safe to say, will be no object.

Kim Jong-un

So, Thaad in South Korea has nothing to do with North Korean rockets and missiles or, for that matter, South Korea. It has everything to do with the US rivalry with China. And it’s not just a matter of frustrating the PRC’s war plans for a conventional A2D2 battle against the US in the Western Pacific.

Thaad in South Korea potentially relates to degrading the viability of the PRC’s land-based strategic nuclear deterrent and a host of knock-on consequences for PRC nuclear doctrine, Air Sea Battle, and the security of the region.

So Thaad is probably too important a strategic gambit to be played unilaterally and misleadingly on the pretext of messing with Kim Jong-un’s rocket party. Even if it doesn’t work.

Peter Lee runs the China Matters blog. He writes on the intersection of US policy with Asian and world affairs.

The opinions expressed in this column are the author’s own and do not necessarily reflect the view of Asia Times.

Peter Lee

Peter Lee runs the China Matters blog. He writes on the intersection of US policy with Asian and world affairs.

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