No Such Thing as a Free Ride? ROK Missile Defence, Regional Missile Defence and OPCON Transfer

Crisis Group’s report on South Korean Intelligence will be released in early August.

In a previous post, we examined South Korean intelligence, surveillance and reconnaissance (ISR) capabilities as they relate to larger alliance dynamics and the issue of the Republic of Korea’s (ROK) military and wartime operational control (OPCON). South Korea also seeks to improve its missile defense (MD) capabilities. While ISR and MD are interrelated, the latter presents its own distinct set of regional and alliance-based issues.

On 3 June, General Curtis Scaparrotti, commander of United States Forces Korea (USFK), recommended the deployment of Terminal High Altitude Area Defence (THAAD) missiles to South Korea. These were the first public remarks by the U.S. military regarding such a deployment, following previous reports of U.S. defence officials stating that it was being considered. The THAAD system reportedly would serve as a more advanced missile-defense system to counter North Korean missile capabilities, which were most recently demonstrated by flight tests of the road-mobile Rodong missile, with a range of more than 1,000km.

While Washington has made no formal proposal to deploy THAAD to the ROK, the U.S. has begun an initial review and carried out site surveys of possible locations. The potential deployment of such a system highlights several ongoing issues that are both technical and highly political in nature. These include upgrading MD capabilities in response to an evolving North Korean threat; the potential expansion of the U.S.-led regional missile defence system, which is part of the U.S. rebalancing strategy in the region; and the ROK’s efforts to upgrade its own MD capabilities while simultaneously balancing its longstanding alliance with the U.S. and its deepening economic and political ties with China.

During testimony last month before the ROK National Assembly’s Foreign Affairs and Unification Committee, former Defence Minister Kim Kwan-jin stated that he would not oppose U.S. deployment of the THAAD system. Kim noted the advantages of the THAAD system if “used together with the Patriot … ground-to-air interceptor”, enhancing “our ability to intercept North Korea’s ballistic missiles”. The new Defence Minister Han Min-koo, who replaced Kim on 30 June, recently reiterated the advantages of THAAD, stating that it would help “strengthening the security posture on the peninsula”. The ROK’s current low-tier Korean Air and Missile Defence (KAMD) system and the THAAD system differ in how they track and intercept incoming missiles, which has implications for ROK defence against a North Korean missile attack.

The ROK’s current Patriot system is the PAC-2, which is only capable of hitting targets at a maximum altitude of 15km using a blast-fragmentation warhead that could send dangerous debris to the ground. The THAAD system is capable of intercepting short-range, medium-range and intermediate-range ballistic missiles at a higher altitude in their terminal phase, between 40km and 150km, and utilises a direct hit-to-kill method. The Lockheed Martin-made THAAD system, equipped with a Raytheon-built AN/TPY-2 X-band radar*, would enhance MD in South Korea by providing more extensive detection, higher altitude intercept capacity and greater accuracy. Moreover, THAAD provides an additional layer of defence that, according to Lockheed, is “interoperable with other ballistic missile defence system elements and can accept cues from Aegis, satellites and other external sensors, as well as work in concert with the Patriot/PAC-3”. This interoperability is salient since the ROK’s KAMD system is equipped with Aegis destroyers and utilises U.S. satellite early-warning launch data. Moreover, the ROK’s Defence Acquisition Program Administration (DAPA) recently announced plans to upgrade its PAC-2 fire control system to enable it to fire both PAC-2 and PAC-3 missiles.

Technical advantages aside, the defence ministry’s remarks have drawn attention as they indicate that the ROK could be moving toward joining a U.S.-led regional ballistic missile defence (BMD) system, a step that Seoul thus far has avoided. One key reason for Seoul’s reluctance has been the potential damage to its increasingly important economic and diplomatic relations with Beijing.

According to the Chinese perspective, the Pentagon is exploiting the DPRK threat as a pretext for enhancing its forces in the region. As Richard Weitz explains, Beijing views U.S. missile defence systems as a potential threat to its own assortment of ballistic missiles, which it employs as a deterrent to Taiwanese independence, a tool to deny U.S. force movements in key coastal regions and airspace, and to intimidate other regional powers. Furthermore, Beijing sees U.S. missile defence enhancements as emboldening U.S. allies to challenge China on territorial disputes by increasing the likelihood of U.S. intervention on their behalf in case of a crisis. Thus, the potential deployment of a THAAD battery to the Korean peninsula has significant strategic implications even apart from Seoul’s potential willingness to integrate its own MD system into a broader U.S.-led system. Beijing has stated that such moves do not bode well for “stability and strategic balance” in the region.

This almost certainly explains why the ROK defence ministry continues to stress the peninsular nature of the potential THAAD deployment. Following former Defence Minister Kim’s remarks that it is “in no way a threat to China”, a spokesman for Defence Minister Han recently reiterated the point. In addition to these assurances, Seoul maintains that it has no plans to purchase its own THAAD system, but has asked the U.S. for data on THAAD only as a reference in establishing its own interceptor system. That said, THAAD is a key component in the U.S.-led regional BMD system. For example, the X-band radar that is integrated in the THAAD system has a detection range exceeding 1,000km, which would put China’s major coastal regions well within its sight. As part of its regional BMD system, the U.S. currently deploys one X-band radar in Japan, with a second planned to arrive before the end of the year, thus deepening Japan-U.S. BMD cooperation, which has been operationally integrated since 2006. For U.S. officials and defence analysts, the missing link remains the ongoing lack of cooperation between the ROK and Japan.

Former Defence Minister Kim vowed to strengthen trilateral cooperation by pushing the General Security of Military Information Agreement (GSOMIA) and the Acquisition and Cross-Servicing Agreement (ACSA) with Japan. Both agreements were expected to be signed in 2012 but Seoul balked due to the Korean public’s outcry over the Lee administration’s perceived lack of transparency, in addition to resurgent historical animosities between Seoul and Tokyo that continue to obstruct adoption of the agreements. However, Kim stressed that such cooperation would be “confined to sharing intelligence on North Korea’s nuclear and missile programs, and the [ROK] government will push for the issue in a transparent way while seeking understanding from the public”. Such developments in missile defence and trilateral cooperation are bound to complicate relations with China.

Consequently, the ROK has been progressively developing its own KAMD system since 2006 while officially maintaining its independence from the U.S.-led BMD system. Currently, KAMD is made of several integrated parts. First, U.S. early warning satellites provide initial detection of missile launches, then U.S. and ROK ground-based and sea-based radar systems track the incoming missile’s flight path. The ROK has two Israeli-made Green Pine land-based radars, and sea-based Aegis SPY-1 radars on its three KDX-III Class destroyers. Second, a central operations center known as the ADM-Cell at Osan Air Base collects and processes this information. The ADM-Cell sends the information to the PAC-2 system equipped with PAC-2 interceptor missiles as well as to the Aegis destroyers equipped with SM-2 Block IIA/B interceptors. As noted, the ROK has plans to upgrade its land-based interceptor to a PAC-3 system with a 30km range by 2020. Furthermore, senior government officials announced plans to arm Aegis destroyers with SM-6 surface-to-air missiles starting in 2016. The deployment of SM-6 missiles with a maximum range of 320-400km would be a notable improvement.

KAMD ostensibly is an independent and indigenous missile defence system. While officially outside of the U.S.-led regional BMD system, KAMD is made up of foreign – mainly U.S.-made – technology and it depends upon U.S. early-warning surveillance satellites to detect North Korean missile launches. Furthermore, assuming an actual North Korean missile attack against the South, U.S. missile defence assets – regardless of type and location – almost certainly would be utilised so that Washington could fulfil its alliance commitments. The U.S. responsibility to employ such resources is codified in the Mutual Defence Treaty between the Republic of Korea and the U.S., which commits each party to come to the defence of the other if under external military attack. And with wartime OPCON under the U.S., the Combined Forces Command (CFC) chain of command goes through the Pacific Command (PACOM) in Honolulu and the Chairman of the Joint Chiefs of Staff (JCS) in Washington. An American CFC commander faced with an external armed attack on a treaty ally would have these regional PACOM assets available and it is virtually certain that they would be used. The mutual defence treaty also works in the other direction. In other words, Seoul would be obligated to assist Washington if the U.S. were to come under a North Korean missile attack. According to the bilateral mutual defence treaty, this means any territory under U.S. administrative control in the “Pacific area”, including the U.S. territory of Guam in addition to numerous U.S. military installations in Japan. In sum, the treaty stipulates that Seoul is obliged to utilise ROK assets to defend areas beyond the Korean peninsula. Indeed, the ROK Navy’s three Aegis destroyers possess the capacity to play such a role. This creates a situation where the ROK, while officially outside the U.S.-led regional BMD system, would be treaty-bound to play a role in regional missile defence. Despite the political inconvenience in Beijing-Seoul relations, the ROK’s planned MD upgrades along with the potential deployment of a THAAD battery to South Korea binds the ROK much more tightly – even if unofficially – into the U.S. regional BMD framework. Recent trilateral discussions, whatever their outcome, strengthen such an impression.

Seoul has argued for further delay of the OPCON transfer and reports indicate such a delay is likely to occur. The stated reason for the delay is the ROK’s continued inability to counter the DPRK’s asymmetric capabilities, including ballistic missiles. Seoul’s missile defence system is one area that remains inadequate to the task. In this sense, Seoul’s planned MD upgrades are a step in the “conditions-based” process in preparation for eventual OPCON transfer. The potential U.S. deployment of a THAAD system could provide an additional layer of defence while the ROK develops its own capabilities. Nevertheless, as noted in the previous post on ISR, the possibility remains that Seoul could view such a deployment as an opportunity for a free ride at U.S. expense, avoiding the immense cost of its own missile defence upgrades.

*Correction: This blog post initially stated that this was a a Raytheon-built X-band radar. It was, however, a Raytheon-built AN/TPY-2 X-band radar.