SEOUL — South Korea has decided to deploy a US advanced missile defense system in the country's southeastern region following years of controversy over the weapon system's effectiveness against North Korea's increasing missile capability.

The plan, however, immediately prompted backlash from North Korea and China, which claim the Terminal High Altitude Area Defense (THAAD) system will intimidate their security postures, as well as local residents fearing the potential health hazards caused by the system's radar.

"By operating the THAAD battery in Seongju, we will be able to better protect one-half to two-thirds of our citizens from North Korean nuclear and missile threats," Ryu Je-seung, deputy defense minister for policy, told reporters July 13.

"It will dramatically strengthen the military capabilities and readiness to defend critical national infrastructure such as nuclear power plants and oil-storage facilities, as well as the military forces of the South Korea-US alliance," said the three-star Army general, adding one THAAD battery is to be deployed at an air base in Seongju by the end of next year.

With a population of 45,000 people, Seongju is located about 240 kilometers from the inter-Korean border.

The defense ministry argues the weapon's location in the southern county enables defense against North Korea's missiles, including the 3,000-kilometer-range Musudan missile and rocket launchers deployed near the border.

The American interceptors, which have an effective range of 200 kilometers, will protect key military installations such as the Gyeryongdae military compound in central Korea and Camp Humphreys, a US force military hub in Pyongtaek, south of Seoul, according to the ministry. The capital area, meanwhile, is out the THAAD coverage area, but would be protected by the lower-tier Patriot system, the thinking goes.

Developed by Lockheed Martin, THAAD can shoot down short-, medium- and intermediate-range ballistic missiles at great speed and altitude. The weapons has been used by the US for years to protect its military units.

A THAAD battery consists of six mobile launchers, 48 interceptors and a radar and fire-control system. The X-Band radar is believed to have a detection range as far as 2,000 kilometers in forward-based mode and 600 kilometers in terminal mode.

"This is an important decision," Gen. Vincent Brooks, commander of US forces in South Korea, said in a statement. "North Korea's continued development of ballistic missiles and weapons of mass destruction require the alliance to take this prudent, protective measure to bolster our missile defense."

North Korea's military issued a warning July 11 that it would retaliate against a THAAD installation in the South.

The North's state-run Korean Central News Agency reported Pyongyang would respond with a "physical counter-action" if the US and South Korea deployed the system.

In an apparent move defying the antimissile plan, the North test-launched its KN-11 submarine-launched ballistic missile July 11, although the test was assessed to be failed.

China's opposition

China is sensitive about the THAAD operation on the Korean peninsula, arguing it would "destabilize the regional security balance."

The deployment "doesn't help achieve the objective of denuclearization in the peninsula, doesn't benefit maintaining peace and stability in the peninsula. It's going toward the opposite direction of solving the problem via dialogue and negotiation," China's foreign ministry said in a statement.

"China will resolutely take the necessary steps to protect our reasonable interests," China's foreign ministry spokesman Lu Kang said.

China's state-backed Global Times even suggested Beijing should come up with military measures, such as directing its missiles toward the THAAD location in Korea.

"The X-Band radar can detect things up to 2,000 kilometers away when it is set for a forward-based mode, which means it could threaten Chinese military posture in an emergency time," said Shin In-kyun, a military analyst at the Korea Defense Network. "The South Korean military pledges the radar will be operated only for terminal mode, but for China, it's hard to believe so because the THAAD is to be operated by the US forces, not the ROK military."

Kwon Young-se, South Korea's former ambassador to Beijing, expressed concerns that the THAAD issue would harm the strategic partnership at a time when China is putting pressure on North Korea's repeated provocations.

"What China is really worried about is that Seoul's potential joining in the US-led regional missile defense network, not just THAAD deployment on the peninsula itself," said Kwon.

Russia reacted angrily, too, hinting at a possible military buildup in response to the ROK-US scheme.

"'In cooperation with the defense ministry, we will work out certain decisions on strengthening of influence in this direction, including through deployment of missile and ground units," Yevgeny Serebrennikov, deputy chair of the Russian upper house's arms committee, said July 8.

Reliability questions

Many experts still cast doubt on whether or not the THAAD system can be effective to thwart North Korean missiles.

Last year, Michael Gilmore, director of the operational test and evaluation directorate at the US Defense Department, said in a report to Congress that the system still lacked the reliability needed for operation in the field.

"Analyses of date from the Reliability Confidence Test and multiple flight tests suggest that THAAD system components are not exhibiting consistent or steadily increasing reliability growth between test events," Gilmore said, adding the US military had succeeded in only nine intercept experiments.

He added the missile shield showed weakness in adapting to different natural environments, such as temperature extremes, humidity, rain, ice, snow, sand, and dust.

Recent simulation experiments here also revealed certain weaknesses, according to Korea Aerospace University.

One simulation presumed a situation that North Korea was firing a mid-range Nodong missile with a nuclear warhead toward a US base in Pyongtaek, 35 kilometers south of Seoul, said professor Jang Young-geun, a military advisor to the defense ministry.

"The simulation showed THAAD failed to shoot down the incoming Nodong missile," Jang noted. It took 203 seconds to detect, track and shoot the interceptor against the incoming missile, but it was too late to take down it, he said.

"THAAD's effective altitude is 40 to 150 kilometers, but the Nodong missile is too fast to intercept within the estimated effective altitude," the professor said, adding that the antimissile system could still defend against missiles flying toward the central or southern region.

Meanwhile, concerns over potential health problems from electromagnetic waves of the powerful radar are growing.

Defense officials contend the missile defense system will be located on a mountain, so it would be harmless so long as people stay at least 100 meters away from it.

But many residents in Seongju do not trust the military's argument, citing a US Army THAAD operational manual that describes the zone of 3.6 kilometers as a personnel-controlled area.

"You can't make a unilateral decision like this when about half of Seongju residents live within 2 kilometers of where THAAD is to be stationed," said Bae Jae-man, a local council speaker, before making a visit to the defense ministry for protest.

Attending a National Assembly session, Defense Minister Han Min-koo rebuffed any safety concerns.

"The US military conducted two evaluations of potential effects on the environment and confirmed operational safety with data from simulations," said the minister. "The conclusion from these evaluations is the THAAD deployment will pose no risk."