After much speculation and discussion, South Korea and the US have finally reached a crucial decision to deploy the Terminal High Altitude Area Defence (THAAD) system. The American-made missile defence system has been a sensitive issue both domestically and in the international arena, but it was a calculated decision by the administration of South Korean President Park Guen-hye to accept the deployment. The THAAD debate tested the durability of Korea’s alliance with the US; Seoul had to choose between the wishes of its most loyal security partner and its largest trade partner – China. US Secretary of State, John Kerry and American military officials have been urging Seoul to consider THAAD since 2015, but South Korea played a game of “strategic ambiguity,” giving no hints of what it might do. One of the concerns for South Korea was the opposition by China, which views THAAD as an American ploy to monitor its military activities and missile locations. 

 

Serious consideration of the system gained momentum after a North Korean nuclear test in January, which was followed by a series of missiles tests. Chinese inability to contain North Korea’s behaviour and its lackadaisical response to the tests did not sit well with President Park, who has tried to woo  since coming to power, hoping that Beijing might use its influence to keep Pyongyang in check. After the North's nuclear test, the South Korean defence minister made an emergency call to his Chinese counterpart through a recently established hotline between the two countries but the call was not answered. President Park subsequently announced that South Korea was reviewing THAAD. Arguably, since Beijing has been unsuccessful in stopping Pyongyang's belligerent activities, which could have addressed Seoul's security concerns, the former, partly, has itself to blame. In February, Admiral Harry Harris, commander of the US Pacific forces, told China that it should have exerted more influence on North Korea if it sought to prevent the deployment of THAAD.

After Seoul and Washington decided to initiate official discussions about THAAD, the response from Beijing was predictably harsh. China’s ambassador to South Korea, Qiu Guohong, warned that there would be instant fallout in bilateral relations. For China, opposition to THAAD has become a bigger issue than controlling North Korea because it feels that the missile defence system will upset the balance of power in the region. China also fears that the AN/TPY-2 radar used in THAAD, which has a range of about 1,800 km, could snoop on its military installations and missile locations, posing a threat to its national security. In order to assuage Beijing’s security concerns, both Seoul and Washington have reiterated that the sole focus of the THAAD system in South Korea would be North Korean nuclear and missile threats and would not target any other countries. Although there have been suggestions of alternatively deploying the South Korean made Korea Advanced Missile Defence (KAMD) in order to deflect Chinese ire, a recent study by Hannam University in Daejeon suggests that the Korean system would not be sophisticated enough to counter a North Korean missile threat even if it were upgraded. In any case, KAMD would not be ready until 2023.

Another area of concern for the US is that North Korean nuclear threats have stimulated the interests of Japan and South Korea in developing nuclear weapons. In April, the Japanese Prime Minister Shinzo Abe announced that the Japanese constitution does not ban the possession of nuclear weapons. In June, US Vice President Joe Biden, during a meeting with Chinese President Xi Jinping, suggested that in the face of North Korea's nuclear threats, Japan may seek nuclear weapons of its own. It is no secret that South Korea has tried to acquire nuclear weapons in the past, and in the aftermath of North Korea's nuclear tests, the South Korean newspaper Chosun Ilbo reported that voices calling for the development of nuclear weapons have been getting louder. Although both Japan and South Korea are signatories to the Non Proliferation Treaty (NPT), it would not prevent them from acquiring nuclear weapons if they felt that US extended deterrence was not enough to meet their national security concerns. Hence, THAAD would not only counter North Korea's perennial threats but help the US protect its allies without setting off a nuclear arms race in Asia.

  

Discussions surrounding THAAD have brought political divisions and protests in the country, but given that its security is dependent on the US, South Korea cannot ignore the interests of its critical ally, which has been protecting the country since the Korean War. Any misadventure by North Korea not only threatens South Korean national security but puts in jeopardy the lives of 28,500 American troops stationed in the country. In order to address doubts over safety concerns, the US military showed off a THAAD battery stationed in Guam to South Korean journalists on 18 July, informing them that the electromagnetic waves emitted by the missile system radar are much lower than permissible levels set by the Korea Communications Commission. 

The coming days will be difficult for South Korea; it must assuage fears over THAAD among its citizens, bring unanimity among the ruling and opposition parties as well as continue to ease Chinese objections. The decision to deploy THAAD is a very difficult one, but also an unavoidable reality. South Korean diplomacy must gingerly balance the delicate relationships between the US and China without compromising its national security interests.