THAAD deployment would bring the United States and South Korea closer at the expense of China's security
Nan Li is a Visiting Senior Research Fellow at East Asian Institute of National University of Singapore
After months of negotiation, the United States and South Korea announced on July 8 their decision to deploy the Terminal High-Altitude Area Defense (THAAD) missile defense system in South Korea. During a press briefing, China’s Defense Ministry spokesman Yang Yujun said that Beijing is “firmly opposed to the proposed THAAD deployment… and will take necessary measures to maintain national strategic security as well as regional equilibrium”.
Why Is China Opposed to THAAD Deployment?
Chinese analysts are particularly concerned about THAAD’s X-band radar. Even though it would be configured as a fire-control radar with a detection range of 600 km, it perhaps could be reconfigured as an early-warning radar, which allows a detection range exceeding 2,000 km. Such a range suggests that China’s missile activities on land and at sea in northern and eastern China may be mostly exposed. The radar allegedly can see the critical processes where warheads and decoys are released during China’s strategic missile tests. In times of war, it can undermine the reliability of China’s strategic deterrent because in comparison with Alaska-based radars, it is believed to be capable of acquiring more than ten minutes of early warning time against China’s strategic ballistic missiles. It can also differentiate real warheads from decoys. If integrated into the U.S. national missile defense network, this radar allegedly can increase the odds of success in intercepting Chinese missiles even at their “boost phase,” reducing further the reliability of China’s already small strategic deterrent and tilting the strategic balance in favor of the United States.
Moreover, Chinese analysts believe that the Korean Peninsula has historically been a nearby sphere critical to China’s security. They worry that by deploying THAAD, South Korea could share data with the United States and Japan on air traffic control, air defense, and early warning. This may help to integrate South Korea-based systems with U.S. and Japanese sensors and sea-based Aegis systems, with the goal of forming a trilateral strategic alliance to contain China at China’s door steps. Chinese analysts believe that North Korean nuclear tests were only an excuse used by the United States to deploy THAAD, the real U.S. intention being to drive a wedge between South Korea and China at a time when China-South Korea relations were improving substantially, as reflected in the countries’ booming bilateral trade and Park Geun-hye’s attendance at the Victory Day Parade in Beijing in September 2015. THAAD deployment would bring the United States and South Korea closer at the expense of China’s security. This could help the United States to stabilize U.S.-South Korea relations and prevent the possible loss of the U.S. military foothold on the Korean Peninsula.
What Countermeasures Might China Take?
Chinese analysts have proposed a wide range of countermeasures to retaliate against the THAAD deployment. They argue that it is time to integrate technologies into Chinese medium-range ballistic missiles that can reinforce their penetration capabilities (突防能力), such as those that can enhance mid-course or terminal maneuverability of warheads to dodge intercepting missiles. These technologies and measures also include integrating decoys to mislead the intercepting missiles, hardening warheads, and building more missiles. They also propose electronic countermeasures to jam THAAD radar. Some believe that China’s flight-tested DF-ZF supersonic missile delivery vehicle, which allegedly can reach the speed of Mach 10, can “turn all missile defense systems obsolete in one night.” Some also argue that in times of war, China should “at the first moment” launch strikes to destroy THAAD. To elude South Korea-based THAAD, Chinese analysts propose to deploy China’s strategic nuclear submarines to the Pacific Ocean for routine patrol. Being highly mobile and more concealed than China’s land-based nuclear deterrent, these submarines can enhance the survivability of China’s sea-based nuclear force, thus enhancing the credibility of China’s second strike nuclear capabilities.
Chinese analysts argue that to restore regional “strategic balance,” China shouldcooperate with Russia in developing strategic offensive weapons, particularly in developing “penetration” technologies that can defeat missile defense. Other proposed countermeasures include concealment and redeployment of China’s strategic capabilities to reduce their exposure to the THAAD radar, and accelerated development of China’s own missile defense systems.
A Moderate View?
While a majority calls for sanctions, there also exists a minority view based on a more nuanced and moderate interpretation of the THAAD deployment. On the effectiveness of THAAD to intercept short-range missiles, this view agrees that a launched North Korean Scud missile targeting Seoul may fly lower than 40 km because of the short range. This missile cannot be intercepted by THAAD because such low altitudes do not match the interception altitudes of THAAD, even though it can be intercepted by South Korea’s Patriot PAC-2/3 interceptors. But if a Scud missile is fired to hit a South Korean target 300 km away, it would reach the maximum height of 80 km and then descend to 40 km in slightly more than a minute, which matches the interception altitudes of THAAD. For this school of thought, a major challenge for South Korea is how to acquire sufficient defenses against North Korean missiles, while at the same time not undermining China’s strategic security. The best option, according to these analysts, is for South Korea to replace the current AN/TPY-2 radar with the Israeli Green Pine radar, which has an effective search range of 500 km. Such a range can provide South Korea sufficient protection against North Korean missiles, while posing no threat to China’s strategic missiles.
China’s security analysts have offered great insights into why China is opposed to THAAD deployment in South Korea, and what countermeasures China might take to “maintain national strategic security as well as regional equilibrium.” However, a few important issues may require closer scrutiny in order to gain a balanced understanding of THAAD deployment in South Korea.
As pointed out by Chinese analysts, it is probably true that the interception altitudes of THAAD match the “terminal phase” of longer-range Chinese ballistic missiles, or those with ranges exceeding 3,500 km, including China’s ICBMs. Of note, however, is that these Chinese missiles are not intended for targets in East Asia. If launched, they are unlikely to have their “descending” or “terminal phase” in this region. So they are less likely to be intercepted by South Korea-based THAAD.
South Korea-based THAAD is more likely intended to intercept China’s medium-range ballistic missiles, or those with ranges between 1,000 and 3,500 km, including China’s DF-21 and DF-26 missiles. This is because these missiles may aim at military targets in the Asia-Pacific region, including U.S. military bases in Japan and on Guam, and its aircraft carrier strike groups deployed in this region. But because North Korea is also developing and deploying medium-range ballistic missiles, it is reasonable to assume that THAAD is intended to intercept both North Korean and Chinese medium-range ballistic missiles.
As mentioned earlier by some Chinese analysts, THAAD can be effective in intercepting a North Korean short-range ballistic missile attempting to hit a South Korean target 300 km away, because its “terminal phase” matches the interception altitudes of THAAD. It is also known that the North Korean ballistic missile arsenal consists mainly of hundreds of modified Scud missiles with ranges between 300 and 700 km. Because these missiles can hit any South Korean target beyond the Seoul area (which is protected by Patriot PAC2/3 interceptors), the primary objective for deploying THAAD in South Korea is in all likelihood for defending against short-range ballistic missiles from North Korea.
Chinese analysts believe that the X-band radar can gain more than ten minutes of early warning time compared to Alaska-based radars against Chinese strategic missiles flying toward the United States, which undermines the reliability of China’s already small strategic deterrent. Assuming this radar can easily be converted to an early-warning radar, however, whatever extra time it can contribute to early warning against Chinese missiles may become less significant for two reasons. One is that the two Japan-based X-band radars can also see the flight paths of Chinese missiles early and provide somewhat similar extra early warning time. The other is that the U.S. ballistic missile early-warning systems based on constellations of satellites, either deployed or under development such as the Space-Based Infrared System, may also be capable of provide early warning time sufficient to marginalize the contribution of the South Korea-based X-band radar.