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How the US can play the missile defence card in Korea

United States Assistant Secretary for Arms Control, Verification and Compliance Frank Rose is visiting Seoul this week to meet his South Korean counterparts and discuss a wide variety of regional security issues.

United States Assistant Secretary for Arms Control, Verification and Compliance Frank Rose is visiting Seoul this week to meet his South Korean counterparts and discuss a wide variety of regional security issues.

Missile defence is reportedly one of these issues, once again stirring up the contentious topic of US’ deployment of the Terminal High Altitude Area Defence (THAAD) on the Korean Peninsula.

In April, North Korea had greeted US Defence Secretary Ashton Carter’s inaugural visit to East Asia by test launching two short-range, surface-to-surface missiles. This prompted pundits and analysts to turn their attention to THAAD to counter North Korea’s growing ballistic missile capabilities.

Chinese leaders have warned Seoul that Sino-Korean relations will be jeopardised should the missile defence system be deployed. Despite this testy scenario, there is a way for the US to utilise THAAD to simultaneously bolster regional security and mould Chinese decision-making.

THAAD is a US-made defence system designed to shoot down ballistic missiles that fly at different levels within, as well as above, the Earth’s atmosphere. THAAD interceptors use a kinetic energy, hit-to-kill approach to destroy ballistic missiles in their terminal phase (when the incoming missile re-enters the atmosphere). The ostensible purpose of the US’ missile defence systems such as THAAD is to defend against missile strikes from rogue states.


North Korea possesses an arsenal of approximately 1,000 ballistic missiles. This arsenal includes the Nodong-1, which boasts a range of 1,200km to 1,500km and can easily reach any target in South Korea and most of Japan, both of which host tens of thousands of US troops.

North Korea has also experimented with launching at higher angles and greater flight altitude, thus allowing the missile a greater chance at dodging South Korea’s existing defences.

On May 9, North Korea once again made headlines after allegedly test-firing a new submarine-launched ballistic missile (SLBM). Though US intelligence sources claim that North Korea is still in the early stages of developing an operational SLBM, the missile test signals Pyongyang’s apparent intention to fortify its nuclear deterrent by rendering its nuclear arsenal less vulnerable to a disabling first-strike by its adversaries.

To counter the threat from the North, Seoul is developing its own Korean Air and Missile Defence (KAMD) system. KAMD will not reach full operational status for some time, however, and is estimated to be more costly than THAAD.

So, why has South Korea not turned to the US for help?

This is because Seoul has found itself in a sensitive position due to China’s opposition to the deployment of THAAD. Although the US is South Korea’s most important security partner, China ranks as South Korea’s largest trading partner.

China’s objections to THAAD are two-fold. First, THAAD’s powerful X-band radar system has an operational range of 1,500km to 2,000km and can be reconfigured to peer deep into Chinese airspace.

Second, North Korean attack against South Korea will most likely consist of artillery shells and, if at all, short-range ballistic missiles that travel within the atmosphere.

Since THAAD is also capable of intercepting threats that fly well above the atmosphere, Chinese leaders surmise that the US aims to target China’s own missile arsenal.

Consequently, the official position of South Korean President Park Geun-hye’s government on THAAD is the “Three Nos”: No decision, no consultation and no request.

That is, Seoul has not yet made an official decision, there has been no consultation between South Korea and the US, and there has been no formal request from the US about deploying THAAD on the Korean Peninsula.


In light of these complicating factors, the Obama administration has three options.

The first option of deploying THAAD on the Korean Peninsula, irrespective of China’s concern, is not advisable. Although the US is used to operating freely throughout the Asia-Pacific, China’s rapidly growing military power has changed the equation.

China has maintained a relatively small and weak nuclear arsenal for minimal deterrence, but it will likely feel the need to modernise its cruise and ballistic missiles as well as nuclear forces to keep pace. This would mire the region in a deadly arms race and sour Sino-US relations.

The second option is to refrain from deploying THAAD altogether. In this scenario, South Korea would be free to pursue its indigenous missile defence system and China will not feel so threatened. This option, however, ignores North Korea’s growing capabilities. Chinese nuclear experts have publicly warned that North Korea may possess as many as 20 nuclear warheads, far exceeding previous estimates.

Pentagon officials also suspect that North Korea already has the ability to miniaturise nuclear warheads onto intercontinental ballistic missiles. This option is also inadvisable as it would be too politically costly.

South Korea’s objections to the THAAD stem from Chinese pressure. By allowing China to dictate the terms of the US’ bilateral alliances in the region, it reaffirms the notion of American retrenchment and sends the wrong message to other US allies and strategic partners.

The third, and most promising, option is for the US to use THAAD as a bargaining chip with China. Beijing can cement its role as an active participant in stabilising the region by pressuring its North Korean ally to refrain from further developing its nuclear programme, rein in missile testing, and curb its belligerence and brinkmanship.

By conditionally offering to refrain from deploying THAAD in return for intensified Chinese pressure on Pyongyang, the Obama administration can provide China with a significant inducement to prove that it is a responsible stakeholder in the region.

If Chinese leaders choose not to cooperate, the US could then consider deploying THAAD with muted radar capabilities. If the operational range of THAAD’s radar system is China’s principal objection, the US can shorten its range to 600km to 800km. This will allow the US to make the deployment much less threatening to China, while still honouring its security commitments to South Korea.

If Beijing continues to object, Washington and Seoul can proceed with the THAAD deployment confident that all viable alternatives have been exhausted.


Harry H Sa is a research analyst with the United States programme at the Institute of Defence and Strategic Studies at the S Rajaratnam School of International Studies, Nanyang Technological University.

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