Weighing South Korea’s options for improving its missile defenses
Seoul needs farsighted policy to respond to North Korean weapons threats while also managing ties with China
Joel Petersson IvreJune 6, 2022
Shortly before taking office, new South Korean President Yoon Suk-yeol released an ambitious 110-point agenda with a surprising omission: It didn’t say anything about Terminal High Altitude Area Defense (THAAD) missile defense batteries, even after Yoon played up the issue throughout his election campaign.
China’s perceptions of THAAD likely factored into the new president’s decision. After Yoon’s election, China’s Ambassador to South Korea Xing Haiming warned that THAAD is a “taboo word in China-South Korea relations.” Chinese diplomats have undoubtedly expressed the same sentiment to Yoon in private.
If Yoon is downplaying THAAD due to concerns about Beijing’s views, he might not be the China hawk he is often made out to be. But Yoon may also be weighing the pros and cons of different ways to boost South Korean missile defenses.
During his campaign, Yoon suggested that South Korea should upgrade its existing THAAD battery, but he later made a short Facebook post that simply said “Additional THAAD deployment.” His adviser Kim Sung-han then clarified that Yoon meant South Korea should purchase its own THAAD battery, as opposed to deploying one operated by the U.S. Yoon’s foreign minister nominee Park Jin adopted a cautious attitude toward additional THAAD deployments in his confirmation hearing.
The Yoon administration’s stance on THAAD is thus far from clear, making it worthwhile to examine the implications of the approaches available to him. What’s most important is that the new president chooses an option that improves South Korea’s long-term security, rather than seeking short-term political gain.
OPTION 1: IMPROVE EXISTING BATTERIES
After U.S. President Joe Biden affirmed that South Korea would receive “the full range of U.S. defense capabilities, including … missile defense capabilities,” the South Korean defense minister said South Korea would push for “normalization” of THAAD. The system has been deployed in a temporary capacity and without full logistical support, which has been delayed by an environmental impact study and local protests.
Other upgrades to the system would entail distancing the launchers from the radar and integrating it with Patriot systems to provide “layered defense.” If this integration only extends to missile defense systems on the Korean Peninsula, the upgrade would not require additional THAAD deployments nor entail regional integration of U.S. missile defenses — both of which China would object to.
Simply upgrading the system would not warrant a response of the kind that China offered in 2016, when unofficial sanctions on South Korea hit its tourism and export sectors hard. Indeed, the Moon administration approved the addition of new launchers to the system in 2017 without protest from China.
Incrementally upgrading THAAD does have drawbacks. The main protection that a missile defense offers is its deterrent effect: An adversary that believes an opponent’s missile defense will work may consequently doubt its own ability to strike a target and not strike at all. Upgrading THAAD without providing a clear signal of its increased capability might not improve this deterrent effect against North Korea.
OPTION 2: U.S. DEPLOYS ADDITIONAL THAAD UNIT
Following the barrage of North Korean missile launches so far this year, the U.S. has stated that it “does not exclude” the possibility of deploying additional THAAD units if Seoul requests it.
The U.S. has seven THAAD batteries, with one already deployed on the Korean Peninsula and one in Guam. The U.S. keeps THAAD systems ready for deployment to allies around the world at short notice and has previously deployed units to Romania, Israel and Saudi Arabia.
The deployment of an additional THAAD battery to the Korean Peninsula is the fastest option available to Yoon but also the one most likely to draw Chinese objections — the likely reason for Park Jin’s cautiousness.
The U.S. Forces Korea would operate an additional battery, and this would heighten Chinese suspicions that the U.S. would attempt to integrate the Korean Peninsula with its regional missile defenses and use the system’s radar to spy into Chinese airspace.
OPTION 3: PURCHASE A THAAD BATTERY FROM U.S.
To alleviate Chinese concerns, Yoon might decide to purchase a THAAD system from the U.S. By purchasing a system to be operated by the South Korean military, Yoon could better argue that the system would be used only against North Korea and not be a part of regional U.S. missile defenses. China is unlikely to accept that excuse, but it could overcome internal opposition to THAAD since South Korean progressives generally favor independent control of military assets.
Purchasing comes with delays, however. South Korea would probably not be able to purchase an existing U.S. system: The U.S. Missile Defense Agency has yet to acquire the nine THAAD systems it deems necessary for its operational needs and would likely be unwilling to share.
South Korea would thus have to get in line behind Saudi Arabia, which placed orders in 2018 for a THAAD system to be delivered by 2023. Even if Seoul could get a deal through faster, acquiring a new THAAD system would take at least three years.
If Yoon is going down this route, it makes sense that he has chosen to downplay the THAAD issue for the time being: Why risk the negative effects of announcing a THAAD deployment if South Korea can’t immediately enjoy the benefits?
OPTION 4: THE DIY SOLUTION
South Korea has also been developing its homegrown missile defense system called Korea Air and Missile Defense (KAMD). The Korean Agency for Defense Development recently announced the development of a domestically produced radar intended to fill a similar role to THAAD.
This alternative is attractive because it would require less U.S. involvement for development, deployment and operation than any of the other three options. KAMD has even been suggested as an alternative to THAAD.
If Yoon is serious about maintaining cordial relations with China, this option would raise the least concern in Beijing, or at least be the most difficult for Beijing to justify a response to. It would also enjoy bipartisan support in South Korea as previous administrations have already put significant efforts into KAMD. As late as January this year, South Korean company Hanhwa Systems signed a deal with the United Arab Emirates to export the Cheonggung II air and missile defense system, which forms a part of KAMD.
The downside is that creating a fully homegrown missile defense will take time. The recently announced radar will not be operational until 2027 — the end of Yoon’s term.
KEEPING COOL
Circumstances can change, and with them Yoon’s calculations. If North Korea does perform a nuclear test, or launches an intercontinental ballistic missile on a non-lofted trajectory, rapid deployment of another U.S. system may be the only answer that is politically feasible for Yoon, even though it would spoil relations with China.
Resisting the urge for rapid deployment to pursue lighter upgrades, a lengthy procurement process or domestic development will require the politically inexperienced Korean president to keep a very cool head. It might be helpful for him to keep in mind that there is considerable debate over whether missile defense systems even work at all.
The logic of arms racing also dictates that improved South Korean missile defense capabilities — however justified — will lead to North Korean efforts to circumvent them, which in turn will require even more drastic countermeasures from South Korea.
The situation on the Korean Peninsula thus does not benefit from measures that only increase security in the short term. Yoon will need to carefully consider his options to improve Korean security in the long run.
Edited by Bryan Betts
Shortly before taking office, new South Korean President Yoon Suk-yeol released an ambitious 110-point agenda with a surprising omission: It didn’t say anything about Terminal High Altitude Area Defense (THAAD) missile defense batteries, even after Yoon played up the issue throughout his election campaign.
China’s perceptions of THAAD likely factored into the new president’s decision. After Yoon’s election, China’s Ambassador to South Korea Xing Haiming warned that THAAD is a “taboo word in China-South Korea relations.” Chinese diplomats have undoubtedly expressed the same sentiment to Yoon in private.
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