South Korea’s THAAD deployment is not appropriate given its geographical and technological inadequacies, diplomatic issues with its neighbors, and defense sovereignty concerns. Instead, other defense systems should be considered.
Terminal High Altitude Area Defense (THAAD) is a “terminal high-altitude area defense system” that would directly shoot down incoming missiles at the terminal stage. It was developed by the U.S. Army as part of the U.S.-led Missile Defense, and its embedded TPY-2 X-band radar detects targets and intercepts warheads in a hit-to-kill, last-ditch effort. Discussions to deploy THAAD in South Korea began in 2011 between the ROK military and the Department of Defense, and in May 2014, U.S. Chairman of the Joint Chiefs of Staff James Winfeld announced that the U.S. was considering deploying THAAD in South Korea to defend against North Korean provocations. Later, in July 2023, U.S. Secretary of State Tony Blinken also hinted at the possibility of including THAAD in the Korean Peninsula missile defense system in a Twitter interview. However, the South Korean government has not taken a clear position due to the many controversies, including strong opposition from China and Russia. In the past, the South Korean government has taken an ambiguous stance, stating that 1) it has no clear plans to implement THAAD, 2) it would be helpful to have it, and 3) it is not opposed to the U.S. military purchasing it on its own budget. Under these circumstances, the South Korean government should oppose THAAD for the following reasons.
First, THAAD is geographically and technologically unsuitable for South Korea. The official purpose of THAAD is to defend against North Korean missile provocations. However, if North Korea were to attack South Korea, its short-range missiles are sufficiently capable of being shot down. After a missile is launched, it goes through three main phases: boost phase, mid-course phase, and terminal phase, and THAAD can only defend against the terminal phase. In addition, THAAD is difficult to intercept at altitudes of 40 kilometers or less. However, the ballistic missiles fired from North Korea to South Korea fly lower than THAAD’s minimum intercept altitude due to their short distance. For example, even if THAAD is deployed as a defense system in the event of a North Korean attack on Japan or Guam, a North Korean ballistic missile would already be at an altitude of more than 700 kilometers by the time it passes over South Korea and would be out of THAAD’s intercept range. In addition, THAAD is a relatively new interceptor, having only been mass-produced since 2005, so it is not perfect. Lockheed Martin, the company that developed THAAD, has publicized its high hit rate, but this was done under optimal conditions, which are very different from real-world conditions, making its reliability questionable. Lockheed Martin has not disclosed THAAD’s actual warhead intercept rates. In the Gulf War, the U.S. military was unable to stop Iraq from launching ballistic missiles, and if North Korea attacks South Korea, it is likely to use a larger amount than in the Gulf War. Therefore, the technical and geographical limitations of THAAD are obvious.
Second, the deployment of THAAD in South Korea can be considered a threat to Northeast Asian countries. THAAD’s X-band detection radar has a detection range of about 1,000 kilometers, which can reach China’s Shandong Peninsula, Shanghai, and Beijing. In addition to the radar, THAAD’s upper layer defense system has an interceptor altitude of 150 kilometers, allowing it to attempt interceptions as far away as Okinawa and Guam. This opens up the possibility of invasion by the U.S. military into neighboring countries, which is why neighboring countries have been negative about THAAD’s deployment in South Korea. On March 16, China’s Vice Foreign Minister Liu Zenchao spoke out against the deployment of THAAD in South Korea, vowing to cut diplomatic ties with South Korea the moment it is deployed. The economic impact of severing diplomatic ties with China, South Korea’s main export market, is expected to be severe. Russia is also strongly opposed to THAAD, and the deployment of THAAD would likely lead to a breakdown in cooperation with Russia. This would be a major blow to the development of South Korea’s defense industry, which relies heavily on Russia. THAAD also poses a threat to South Korea’s defense sovereignty. The deployment of THAAD in South Korea would mean the integration of South Korea’s missile defense system with the missile defense system of the U.S. Forces Korea. This could result in the transfer of Korea’s defense sovereignty to the USFK.
Third, the deployment of THAAD deepens South Korea’s military dependence on the United States. While some argue that THAAD’s superior interceptor capabilities and threatening presence are the reason for its introduction, THAAD is not the only military alternative that can fulfill the intercept and defense mission. South Korea has the Patriot, a low-altitude, short-range interceptor ballistic missile, and the Arrow, an upper-level defense interceptor ballistic missile like THAAD that was developed in Israel. Arrow has been deployed since the early 2000s and has shown excellent hit and intercept rates through continuous improvements. It is also considered the most suitable weapon system for the South Korean missile defense system KAMD. These alternatives can also serve as a weapon for neighboring countries, and can fully fulfill the purpose of South Korea’s defense. The introduction of THAAD would only deepen South Korea’s military dependence on the United States.
The U.S. military’s demand for THAAD ignores the political and diplomatic situation in South Korea and the geographical and technical limitations of THAAD itself. The political damage from neighboring countries’ opposition to THAAD would be significant. The South Korean government has maintained a policy of strategic ambiguity and 3NO (No Request, No Consultation, No Decision) regarding the deployment of THAAD in South Korea. While the decision to deploy THAAD is difficult, it is not appropriate for South Korea to deploy THAAD domestically, given its many diplomatic ties and practical defense benefits.
