The continuing development of North Korea's nuclear and missile capabilities is testing the readiness and long-term planning of South Korea's missile defences. The plans will undoubtedly be overshadowed by Chinese concerns.
The recent nuclear test by North Korea follows on from the provocative Unha-3 rocket launch of late last year, the ultimate goal to develop an intercontinental ballistic missile (ICBM) capable of hitting the US mainland. North Korea is working towards a miniaturised nuclear warhead but despite recent advancements, this is some time away from fruition and questions still remain about the variety and deliverability of its nuclear arsenal. Â Â
While it must be emphasised that recent decisions regarding South Korea's Ballistic Missile Defence (BMD) capabilities were made before the December missile launch and February nuclear test, the growing sophistication of North Korea's recent tests has put the readiness and long-term planning of South Korea's deterrence and BMD capabilities under scrutiny.
Before the North Korean rocket launch of December 2012, South Korea in agreement with the US, announced the New Missile Guidelines (NMG). This would enhance deterrence capabilities against the North Korean missile threat and would, according to the White House, be a 'prudent, proportional, and specific response to the DPRK'. Seoul can now develop missiles with a 500kg payload, with ranges up to 800km, up from a limit of 300km (a sufficient range to be able to strike North Korean targets).
With the application of a 'trade off' rule, South Korea can also deploy shorter-range missiles (up to 300km) with a heavier payload above 500kg. Cruise missiles with an unlimited range, with a payload of up to 500kg can also be utilised. Cruise missile capabilities have been pursued due to the previous restrictions regarding ballistic missiles. In a timely riposte to the recent nuclear test, it was announced that new precision strike cruise missiles, launched via submarines or Aegis destroyers would be deployed. This is likely to be a modified version of the highly accurate indigenous Hyunmu-3C, comparable with the US-made Tomahawk missile, which is noted for its accuracy in attacking well defended targets and fixed sites such as command and control centres and air defences.
The NMG revisions reflect the changing dynamics of the US-South Korean relationship and are also a precursor to the transition of wartime operational control (OPCON) from the US to South Korea, scheduled to occur in 2015. Whilst it is the intention of the US to provide bridging capabilities leading up to the transition, issues of operational autonomy and how closely South Korean forces will be tethered to the US military presence on the Korean peninsula remain unresolved. The NMG framework attempts to focus on, and provide practical considerations to deter North Korean capabilities. There is also an element of prestige-seeking at play, with missile development intended to provide an effective signal to a domestic audience and the North Koreans who launched a satellite into orbit before their neighbours.
Chinese Concerns
The revised guidelines have wider ramifications due to the dynamics and volatility of the region. South Korea's extended missile ranges will irk China as parts of its territory will be within range. It will also fuel perceptions that this is part of the US strategic shift towards the Asia-Pacific region. The US would certainly welcome more fruitful ties between South Korea and Japan and US-led BMD cooperation would be a tangible way of enhancing such a relationship.
This would invite further Chinese scepticism, similar to Russian concerns regarding the US European Phased Adaptive Approach (EPAA). Such a system would undermine their deterrent capabilities as well as erode bilateral strategic stability. China would also find the prospect of further deployments of US X-band radars in East Asia (Japan and the Philippines) to monitor North Korean missile threats questionable. These radars would geographically cover Taiwan and could help enable interception of Chinese conventional medium-range missiles. China is also testing missile defence intercept technology with a view to understanding US systems better.
Despite a background of strained diplomacy and on-going island disputes, the recent leadership changes in South Korea, China and Japan may also present an opportunity for regional detente and a refreshing of relations.
South Korean Missile Defence - An Emerging yet Limited System
To counter the developing North Korean missile threat and its already deployable Scud and ballistic missile capabilities, South Korea is working on a combined missile defence system with the US, utilising an emerging Korean Air and Missile Defense system (KAMD) and Patriot and satellite assets provided by the United States Forces Korea (USFK).
This is intended as a regionally specific system, expand upon limited land-based theatre capabilities and versatile maritime assets such as KDX-III Aegis Destroyers to deal with derivatives of the Scud-C and Scud-D, variants of the Russian SS-21 'Scarab' and medium-range Rodong missiles. The system will consist of surveillance platforms such as the land-based Israeli early warning Green Pine radar and the maritime Aegis SPY-1D radar. Such radars are integral to developing an Air and Missile Defence-Cell (AMD-Cell), providing command-and-control, monitoring, tracking and interception of incoming cruise and ballistic missiles from North Korea. This is due to be become operational by 2015 to coincide with the transfer of OPCON but the recent nuclear test may accelerate the process for early deployment.
In terms of interceptors, Patriot PAC-2 GEM/T batteries will be augmented by the Patriot PAC-3, to provide increased effectiveness against tactical ballistic and cruise missiles. An upper tier indigenous capability (but based on Russian technology) will be provided by the Cheolmae 4-H missile, with a range of 150km.
South Korean Aegis destroyers are equipped with SM-2 missiles, whose primary function is to defend against enemy aircraft and anti-ship missiles.  Together with the anticipated procurement of SM-6 missiles, these assets will provide a limited defence against low-altitude ballistic missiles. This could be interpreted as a cost-effective measure, compared to the more expensive SM-3 variants, designed specifically to intercept short- to intermediate-range ballistic missiles. It is likely however that SM-3 equipped US Navy Aegis Destroyers would be a deployable option in support of US backing of South Korea should tensions escalate  especially to defend US military assets based there. Â
Conditions for International Cooperation
The long-term intention is interoperability within a wider US-led regional system. This would have shared situational awareness, enhanced early-warning radar technology and a variety of proven interception systems. It is already obvious that South Korea's first priority is to safeguard its own theatre capabilities, whilst not wanting to provoke China and Russia, who are both critical of US missile defence policy.
Further afield, the successful first test of the Arrow-3 high-altitude interceptor has shown how Israel's unique expertise (along with US backing) to deploy and modify BMD assets rapidly and attempts to mould them into a cohesive and integrated architecture can provide a template for South Korea in its BMD planning. Considering the linkages between the three countries, it is envisaged that Boeing and the state-owned Israel Aerospace Industries (IAI) - partners in production of the Arrow-2 and planned Arrow-3 long-range interceptors - would seek to create opportunities to sell these systems to South Korea. South Korean responses to such an overture will be telling, especially when seen in the light of not wanting to further infuriate China.
There is a focus on developing a very specific South Korean BMD system to counter North Korean threats (whilst also minimising Chinese dissent towards such capabilities). However, greater momentum towards a US-led wider regional architecture is currently lacking due to the absence of multilateral dynamics that have created the drive for missile defence within NATO. Rather, the US has had to formulate a strategy of trilateral cooperation which, it is hoped, will eventually pave the way for a regional system once consensus has been reached on joint security interests and perceptions. As ever, Chinese concerns will continue to overshadow such ambitions.